#China (People's Rep. of) - #Influenza A #H5 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

Wild Species (unspecified) in Xinjiang Uygur Region.

Source: 

Link: https://wahis.woah.org/#/in-review/6978

____

Effectiveness of high-dose #influenza #vaccine against #hospitalisations in older #adults (FLUNITY-HD): an individual-level pooled analysis

 

Summary

Background

Two large-scale trials comparing high-dose inactivated influenza vaccine (HD-IIV) versus standard-dose inactivated influenza vaccine (SD-IIV) against hospitalisation outcomes have been conducted in Denmark and Spain. We aimed to analyse the pooled data from these trials to enhance generalisability and assess the relative vaccine effectiveness (rVE) of HD-IIV versus SD-IIV against severe clinical outcomes in older adults.

Methods

FLUNITY-HD was a prespecified, individual-level pooled analysis of two methodologically harmonised pragmatic, individually randomised trials comparing HD-IIV with SD-IIV in older adults. DANFLU-2 included adults aged 65 years or older and GALFLU included community-dwelling adults aged 65–79 years. DANFLU-2 was conducted during the 2022–23, 2023–24, and 2024–25 influenza seasons in Denmark, whereas GALFLU was conducted during the 2023–24 and 2024–25 seasons in Galicia, Spain. In both trials, participants were randomly assigned (1:1) to receive either HD-IIV (60 μg of haemagglutinin [HA] antigen per strain) or SD-IIV (15 μg of HA antigen per strain) and followed up for the occurrence of endpoints from 14 days after vaccination to May 31 the following year in each season. Routine health-care databases were used as primary data source. The primary endpoint of both the pooled analysis and the individual trials was hospitalisation for influenza or pneumonia. Secondary endpoints were tested hierarchically, and consisted of hospitalisation for any cardiorespiratory disease, laboratory-confirmed influenza hospitalisation, all-cause hospitalisation, all-cause mortality, hospitalisation for influenza (ICD-10), and hospitalisation for pneumonia. The pooled analysis is registered with ClinicalTrials.gov, NCT06506812.

Findings

The analysis included 466 320 individually randomised participants (233 311 were randomly assigned to HD-IIV and 233 009 to SD-IIV). Mean age was 73·3 years (SD 5·4); 223 681 (48·0%) were female and 242 639 (52·0%) were male. 228 125 (48·9%) participants had at least one chronic condition. The primary endpoint of hospitalisation for influenza or pneumonia occurred in 1312 (0·56%) of 233 311 participants in the HD-IIV group compared with 1437 (0·62%) of 233 009 participants in the SD-IIV group (rVE 8·8%, 95% CI 1·7 to 15·5; one-sided p=0·0082). HD-IIV also reduced the incidence of cardiorespiratory hospitalisation (4720 [2·02%] participants in the HD-IIV group vs 5033 [2·16%] participants in the SD-IIV group; rVE 6·3%, 2·5 to 10·0; p=0·0006), laboratory-confirmed influenza hospitalisation (249 [0·11%] participants vs 365 [0·16%] participants; rVE 31·9%, 19·7 to 42·2; p<0·0001), and all-cause hospitalisation (19 921 [8·54%] vs 20 348 [8·73%]; rVE 2·2%, 0·3 to 4·1; p=0·012). All-cause mortality occurred with similar frequency in both groups (1421 [0·61%] vs 1437 [0·62%]; rVE 1·2%, –6·3 to 8·3; p=0·38). ICD-10-coded hospitalisation for influenza occurred in 164 (0·07%) participants in the HD-IIV group and 271 (0·12%) participants in the SD-IIV group (rVE 39·6%, 26·4 to 50·5) and hospitalisation for pneumonia occurred in 1161 (0·50%) participants in the HD-IIV group and 1187 (0·51%) participants in the SD-IIV group (rVE 2·3%, –6·0 to 10·0). The incidence of serious adverse events was similar between groups (16 032 events in the HD-IIV group and 15 857 events in the SD-IIV group).

Interpretation

In this prespecified pooled analysis, HD-IIV demonstrated superior protection compared with SD-IIV against hospitalisation for influenza or pneumonia and also reduced the incidence of the secondary endpoints of cardiorespiratory hospitalisation, laboratory-confirmed influenza hospitalisation, and all-cause hospitalisation. Given wide eligibility for influenza vaccination, implementing HD-IIV could result in substantial public health benefits.

Funding

Sanofi.

Source: 

Link: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)01742-8/abstract?rss=yes

____

Rebalancing viral and immune #damage versus repair prevents #death from lethal #influenza #infection

 

Abstract

Maintaining tissue function while eliminating infected cells is fundamental, and inflammatory damage plays a major contribution to lethality after lung infection. We tested 50 immunomodulatory regimes to determine their ability to protect mice from lethal infection. Only neutrophil depletion soon after infection prevented death from influenza. This result suggests that the infected host passed an early tipping point after which limiting innate damage alone could not rescue lung function. We investigated treatments that could have efficacy when administered later in infection. We found that partial limitation of viral spread together with enhancement of epithelial repair, by interferon blockade or limiting CD8+ T cell–mediated killing of epithelial cells, reduced lethality. This finding highlights the importance of rebalancing repair and damage processes in the survival of pulmonary infections.

Source: 

Link: https://www.science.org/doi/10.1126/science.adr4635

____

#Pathogenesis and Transmissibility of #MERS #Coronaviruses of African Origin in #Alpacas

 

Abstract

The Middle East respiratory syndrome coronavirus (MERS-CoV) remains a highly significant threat to global public health. Dromedary camels are the zoonotic source of human infection. All cases of zoonotic Middle East respiratory syndrome (MERS) have occurred in Middle Eastern countries despite MERS-CoV infection of camels being widespread in Africa. This disparity in the geographic burden of the disease may be due to genomic differences between MERS-CoV circulating in Middle Eastern countries (clades A and B) versus those infecting camels in Africa (clade C), although the precise genetic determinants of virulence remain to be elucidated. The objective of the studies reported here was to evaluate differences in the magnitude of virus shedding and in transmissibility of clades A/B and C viruses using alpacas as a surrogate for dromedary camels. We found that two of three African-origin, clade C strains of MERS-CoV induced very reduced levels of virus shedding and were transmitted inefficiently to contact control animals as compared to one other clade C virus and representative viruses from clade A and B. Lower virus titers in the nasopharynx may be associated with lower zoonotic transmission and human disease severity and may explain the observed epidemiology of MERS-CoV in Africa where zoonotic disease appears rare. These results add to our understanding of the transmission of different lineages of MERS CoV in camelids and zoonotic transmission.

Source: Viruses, 

Link: https://www.mdpi.com/1999-4915/17/11/1524

____

#Austria - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

 

A poultry farm in Oberösterreich Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7024

____

#Korea (Rep. of) - #Influenza A #H5N9 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

A wild Common Teal in Jeollabuk-do Region.

Source: 

Link: https://wahis.woah.org/#/in-review/6983

____

Post #COVID19 #resurgence of #Mycoplasma pneumoniae infections in French #children (ORIGAMI): a retrospective and prospective multicentre cohort study

 

Summary

Background

Following a decline during the COVID-19 pandemic, Mycoplasma pneumoniae infections resurged in several countries. We aimed to characterise the clinical presentation of paediatric patients admitted to hospital for M pneumoniae during 2023 and 2024 in France.

Methods

We conducted a nationwide, multicentre, retrospective, and prospective observational study across 37 French paediatric hospitals (September, 2023–September, 2024). Children younger than 18 years who were hospitalised with laboratory-confirmed M pneumoniae infection (PCR or serology) were included. Demographics (excluding race), clinical features, laboratory and radiological findings, management, and outcomes data were described and analysed. Logistic regression was used to identify factors associated with paediatric intensive care unit (PICU) admission. The trial was registered at ClinicalTrials.gov (NCT06260371) and is complete.

Findings

We included 969 children and adolescents with M pneumoniae infection (7·3 years [SD 4·5], 426 [44%] of 966 patients were female and 540 [56%] of 966 were male). 936 (97%) of all patients were positive by PCR for M pneumoniae. Pneumonia was diagnosed in 628 (87%) of the 726 patients with respiratory involvement, and cutaneous manifestations were reported in 132 (14%) of 969 patients, including 56 (42%) of 132 who had erythema multiforme. Macrolides were prescribed in 884 (95%) of the 931 patients who were prescribed antibiotics, primarily azithromycin (563 [64%] of 884). Macrolide resistance was detected in one (5%) of the 21 tested samples. In total, 57 (6%) of 969 patients required PICU admission and four (<1%) died. Factors significantly associated with PICU admission included being older than 11 years (adjusted odds ratio 2·0 [95% CI 1·1–3·6]; p=0·023), asthma (2·2 [1·2–4·0]; p=0·0072), other underlying conditions (2·1 [1·2–3·7]; p=0·013), and erythema multiforme (3·7 [1·6–8·8]; 0·0025).

Interpretation

The 2023–2024 M pneumoniae epidemic in France resulted in a substantial paediatric hospitalisation burden. Although severe cases were uncommon, children older than 11 years, those with asthma, other comorbidities, and erythema multiforme were at increased risk of PICU admission. Ongoing surveillance and targeted management strategies are warranted for future epidemics.

Funding

Association Clinique et Thérapeutique Infantile du Val de Marne (ACTIV).

Source: 

Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00598-5/abstract?rss=yes

____

Efficacy, Immunogenicity, and Safety of Modified #mRNA #Influenza #Vaccine

Abstract

Background

Influenza remains a major health burden despite the use of licensed vaccines. Nucleoside-modified messenger RNA (modRNA) influenza vaccines have shown promising immunogenicity against influenza and an acceptable safety profile in a phase 1–2 trial.

Methods

In this phase 3 trial, we randomly assigned healthy adults between the ages of 18 and 64 years to receive either a quadrivalent modRNA influenza vaccine (modRNA group) or a licensed inactivated quadrivalent influenza vaccine (control group) during the 2022–2023 influenza season in the United States, South Africa, and the Philippines. The primary end point was relative efficacy, defined by the reduction in the percentage of participants with laboratory-confirmed influenza associated with influenza-like illness at least 14 days after vaccination with the modRNA vaccine, as compared with the control vaccine, and analyzed for noninferiority and superiority. Immunogenicity was evaluated by means of a hemagglutination inhibition (HAI) assay. We assessed reactogenicity within 7 days after vaccination, adverse events through 1 month, and serious adverse events through 6 months. We assessed vaccine efficacy, immunogenicity, and safety in the modRNA group.

Results

A total of 18,476 participants underwent randomization: 9225 were assigned to receive the modRNA vaccine and 9251 to receive the control vaccine. The relative efficacy of the modRNA vaccine as compared with the control vaccine against influenza-like illness was 34.5% (95% confidence interval [CI], 7.4 to 53.9) on the basis of 57 cases in the modRNA group and 87 cases in the control group, a finding that met the criteria for both noninferiority and superiority. Cases of influenza-like illness were caused by A/H3N2 and A/H1N1 strains but almost no B strains. The noninferiority of the antibody response on HAI assay was shown for influenza A strains but not for B strains. Primarily mild or moderate reactogenicity was observed in both vaccine groups but was reported more frequently in the modRNA group (overall local reactions, 70.1% vs. 43.1%; overall systemic events, 65.8% vs. 48.7%). Fever occurred in 5.6% of the participants in the modRNA group and in 1.7% of those in the control group. Adverse event profiles were similar in the two groups.

Conclusions

The modRNA vaccine had statistically superior efficacy over the control vaccine, with greater immune responses to A/H3N2 and A/H1N1 strains, but was associated with more reactogenicity events. (Funded by Pfizer; C4781004 ClinicalTrials.gov number, NCT05540522.)

Source: The New England Journal of Medicine

, https://www.nejm.org/doi/full/10.1056/NEJMoa2416779?query=TOC

____

Swine acute #diarrhea syndrome #coronavirus-related viruses from #bats show potential #interspecies infection

 

ABSTRACT

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a bat-originated virus causing severe diseases in piglets. Since the 2016 outbreak, diverse SADS-related CoVs (SADSr-CoVs) have been detected in Rhinolophus bats in China and Southeast Asia, but their potential interspecies infection and pathogenicity remain unknown. Herein, we sequenced the spike (S) genes of bat SADSr-CoVs and classified them into four genotypes. We constructed an infectious SADS-CoV cDNA clone (rSADS-CoV) and nine recombinant viruses by replacing the SADS-CoV S gene with that of bat SADSr-CoVs. Recombinant SADSr-CoVs could replicate efficiently in respiratory and intestinal cell lines and human- and swine-derived organoids and caused varying tissue damage and mortality in suckling mice. These viruses can be classified into at least five serotypes based on cross-neutralization assays. Our findings highlight the potential risk of interspecies infection and provide important information for future surveillance of these bat viruses.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.02240-24?af=R

____

#Spike conformational and glycan heterogeneity associated with #furin cleavage causes incomplete #neutralization of #SARS-CoV-2

 

Abstract

SARS-CoV-2 Spike - the sole neutralization target, is highly resilient to the immune pressure driving genetic evolution. While potency and breadth of neutralization are widely studied, the incomplete neutralization - the mechanism of resistance without needing genetic change - remains unexplored. Several monoclonal antibodies, although potent, showed incomplete neutralization of genetically homogeneous pseudovirus suggesting the existence of distinct spike conformations. The residual infectivity at high antibody concentration indicates a viral fraction with intrinsic resistance to the antibody. Although the published studies on spike glycosylation, structure, and conformations provide evidence of spike heterogeneity the precise mechanism for the incomplete neutralization has not been established. In this study, we devise a method to separate the un-neutralized virion population, called as persistent fraction of infectivity (PF), and characterize the viral spike protein. The neutralization resistance of PF is stable and unrelated to the conformational equilibrium that exists in the pseudovirus stock. The spike on the PF is highly cleaved between S1 and S2, adopts the closed conformation, and express more mannosidic glycans on RBD than the total virus population. Our study provides possible explanations for the incomplete neutralization by antibodies and delineates the association between furin cleavage of spike, its conformation and glycosylation.

Source: Nature Communications, https://www.nature.com/articles/s41467-025-65099-y

____

Increased #pathogenicity and #transmission of #SARS-CoV-2 #Omicron #XBB.1.9 subvariants, including HK.3 and EG.5.1, relative to BA.2

 

ABSTRACT

With the SARS-CoV-2 Omicron XBB.1.9 subvariants circulating worldwide, two XBB.1.9 variants, EG.5.1 and HK.3, spread rapidly and became dominant in mid-2023. However, the spike features, pathogenicity, and transmissibility of HK.3 are largely unknown. Here, we performed multiscale investigations to reveal the virological features of XBB.1.9 subvariants, including the newly emerging HK.3. HK.3 revealed high replication efficiency and enhanced TMPRSS2 utilization in vitro. The HK.3 spike exhibited enhanced processing, although its infectivity, fusogenicity, and human ACE2 (hACE2) binding affinity were comparable to those of the EG.5 and XBB.1 spikes. All XBB.1.9.1, EG.5.1, and HK.3 strains demonstrated efficient transmission in hamsters, although XBB.1.9.1 exhibited stronger fitness in the upper airways. XBB.1.9.1, EG.5.1, and HK.3 exhibited greater pathogenicity than BA.2 in H11-K18-hACE2 hamsters. Our studies provide insights into the newly emerging pathogens EG.5.1 and HK.3.

IMPORTANCE

SARS-CoV-2 Omicron continues to circulate and evolve into novel lineages with indistinguishable pathogenicity and transmission. Ancestral Omicron lineages, such as BA.1 and BA.2, revealed attenuated pathogenicity and transmission, at least in animal models. However, on a previously reported Omicron-sensitive H11-K18-hACE2 hamster model, the infections of XBB.1.9 lineages, EG.5, and HK.3 led to faster lethality and more severe terminal bronchioles symptom than BA.2. They also revealed efficient transmission in a hamster model, which corresponds well with their prevalence in multiple countries. Our study highlights the importance of surveillance and virological studies on epidemic Omicron subvariants.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.01342-25?af=R

____

Estimated #impact of 2022–2023 #influenza #vaccines on annual #hospital #burden in the #USA

 

Significance

Annual influenza epidemics in the United States cause hundreds of thousands of hospitalizations. Quantifying vaccine impact is vital, yet many analyses overlook vaccines’ dual benefits: directly protecting recipients and indirectly protecting their contacts. Using a mathematical model that accounts for both effects, we estimate that vaccination prevented about 70,000 hospitalizations during the 2022–2023 season, with another 19,000 potentially avoidable if coverage met the 70% national target. Despite uncertainty in vaccine effectiveness against infection, our findings suggest that vaccinating younger adults offers substantial indirect protection for older adults. Tailoring annual vaccination campaigns by age group and state could further strengthen their public health impact.

Abstract

During the COVID-19 pandemic early years, infection prevention measures suppressed transmission of seasonal influenza and other respiratory viruses. The early onset and moderate severity of the US 2022–2023 influenza season may have resulted from reduced use of nonpharmaceutical interventions or lower population immunity after 2 y of limited influenza virus circulation. We used a mathematical model of influenza virus transmission that incorporates vaccine-derived protection against both infection and severe disease to estimate the impact of influenza vaccines on healthcare burden. Assuming reported levels of past vaccine effectiveness (VE) against infection and hospitalization, we estimate that influenza vaccines prevented 69,886 (95% CI: 51,860 to 84,575) influenza-related hospitalizations nationwide during the 2022–2023 season, with 57% attributable to reduced susceptibility and onward transmission. Despite limited data on VE against infection, our analyses suggest substantial indirect protection, particularly from young adults to other age groups. This is supported by a significant negative correlation between young adult (aged 18 to 49 y) vaccination rates and observed hospital burden across US states. Among those aged ≧65 y, nearly half of averted hospitalizations resulted from vaccinating younger age groups. These findings highlight the need for better estimates of influenza VE against infection and the potential benefits of increasing young adult influenza vaccination rates to reduce both direct and indirect disease burden.

Source: Proceedings of the National Academy of Sciences of the United States of America, https://www.pnas.org/doi/abs/10.1073/pnas.2505175122?af=R

____

#Influenza at the #human - #animal #interface - Summary and #risk #assessment, from 30 September to 5 November 2025 (#WHO)

 

• New human cases{1,2}: 

-- From 30 September to 5 November 2025, based on reporting date, the detection of influenza A(H5N1) in one human, A(H5N2) in one human and A(H9N2) in two humans were reported officially.  

• Circulation of influenza viruses with zoonotic potential in animals: 

-- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species continue to be reported to the World Organisation for Animal Health (WOAH).{3} 

-- The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4} 

• Risk assessment{5}: 

-- Sustained human to human transmission has not been reported in the above human infection events. 

-- Based on information available at the time of this risk assessment update, the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and remains low. 

-- The occurrence of sustained human-to-human transmission of these viruses is currently considered unlikely. 

-- Although human infections with viruses of animal origin are infrequent, they are not unexpected at the human-animal interface.  

• IHR compliance{6}: 

-- This includes any influenza A virus that has demonstrated the capacity to infect a human and its haemagglutinin (HA) gene (or protein) is not a mutated form of those, i.e. A(H1) or A(H3), circulating widely in the human population. 

-- Information from these notifications is critical to inform risk assessments for influenza at the human-animal interface.  

Avian influenza viruses in humans 

Current situation:  

-- Since the last risk assessment of 29 September 2025, one laboratory-confirmed human case of A(H5N1) infection was detected in Cambodia, and one laboratory-confirmed human case of A(H5N2) virus infection was detected in Mexico. 

A(H5N1), Cambodia 

-- On 15 October 2025, Cambodia notified WHO of a laboratory-confirmed human infection with HPAI avian influenza A(H5N1) in a girl from Kampong Speu Province. 

- The case, with no known underlying medical conditions, had an onset of fever on 4 October and was admitted to hospital on 12 October. 

- Nasopharyngeal and oropharyngeal swabs collected on 13 October tested positive for avian influenza A(H5N1) at the Institut Pasteur du Cambodge (the National Influenza Centre (NIC) by reverse transcription-polymerase chain reaction (RT-PCR). 

- Laboratory results were confirmed at the National Institute of Public Health. 

- Treatment with oseltamivir was initiated on 14 October. 

- The case fully recovered and was discharged on 23 October. 

- Respiratory samples collected from 11 close contacts and one symptomatic villager tested negative for influenza A(H5N1) virus. 

- Field investigations revealed that backyard chickens had died in the weeks preceding the detection of the human case. 

- Although no clear history of direct exposure to sick or dead chickens was identified, it was reported that the case frequently played around the house and in the nearby backyard where the chickens had died.

- Seventeen human infections with A(H5N1) viruses have been confirmed in Cambodia in 2025 and eight of these have been fatal. 

- All these cases in 2025 had exposure to domestic birds or their environments. 

- In some cases, domestic birds were reported to be sick or dead. 

- Where the information is available, the genetic sequence data from the viruses from the human cases closely matches that from recent local animal viruses and are identified as clade 2.3.2.1e viruses. 

- From the information available thus far on these recent human cases, there is no indication of human-to-human transmission of the A(H5N1) viruses.  

A(H5N2), Mexico 

- On 2 October 2025, Mexico notified PAHO/WHO a laboratory-confirmed case of avian influenza A(H5) virus infection detected in an adult, resident of Mexico City. 

- The case had an onset of respiratory symptoms on 14 September and was hospitalized on 28 September. 

- A bronchoalveolar lavage sample collected on 29 September tested positive for unsubtypable influenza A. 

- On 30 September, further testing by real-time RT-PCR confirmed the presence of influenza A(H5) virus. 

- The sample was subsequently sent to the National Influenza Centre, the National Institute of Epidemiological Diagnosis and Reference (InDRE), which confirmed avian influenza A(H5) through molecular diagnostics. 

- The neuraminidase was identified as N2. 

- The sample was sent to a WHO Collaborating Centre for influenza for further characterization.  

- Respiratory samples collected from close contacts including hospital contacts, tested negative for influenza viruses. 

- During the epidemiologic investigation, several animals (including birds) and bird droppings were found in the building where the case resides, in an area the case passes frequently. 

- A dog was identified as a pet at the case’s residence. 

- Samples collected from the animals tested positive for influenza A(H5). 

- Information on whether this virus was a high or low pathogenicity avian influenza virus (HPAI or LPAI) is pending further testing. 

- This is the third human case of avian influenza A(H5) in Mexico since 2024 and the first case in Mexico City. 

- In 2024, a human case of infection with an influenza A(H5N2) virus was detected in a resident of the state of Mexico. 

- In 2025, a human case of infection with an influenza A(H5N1) virus was detected in the state of Durango. 

- Ongoing outbreaks of A(H5) viruses in birds have been detected in multiple states in Mexico since 2022. 

- According to reports received by WOAH, various influenza A(H5) subtypes continue to be detected in wild and domestic birds in Africa, the Americas, Asia and Europe. Infections in non-human mammals are also reported, including in marine and land mammals.{7} 

- A list of bird and mammalian species affected by HPAI A(H5) viruses is maintained by FAO.{8}

Risk Assessment for avian influenza A(H5) viruses:  

-- 1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5) viruses?  

- Most human infections so far have been reported in people exposed to A(H5) viruses, for example, through contact with infected poultry or contaminated environments, including live poultry markets, and occasionally infected mammals and contaminated environments. As long as the viruses continue to be detected in animals and related environments humans are exposed to, further human cases associated with such exposures are expected but remain unusual. The impact for public health if additional sporadic cases are detected is minimal. The current overall global public health risk of additional sporadic human cases is low. 

-- 2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H5) viruses related to the events above?  

- No sustained human-to-human transmission has been identified associated with the recent reported human infections with avian influenza A(H5) viruses. There has been no reported human-to-human transmission of A(H5N1) viruses since 2007, although there may be gaps in investigations. In 2007 and the years prior, small clusters of A(H5) virus infections in humans were reported, including some involving health care workers, where limited human-to-human transmission could not be excluded; however, sustained human-to-human transmission was not reported.  Current evidence suggests that influenza A(H5) viruses related to these events did not acquire the ability to efficiently transmit between people, therefore sustained human-to-human transmission is thus currently considered unlikely.  

-- 3. What is the likelihood of international spread of avian influenza A(H5) viruses by travellers?  

- Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community-level spread is considered unlikely as current evidence suggests these viruses have not acquired the ability to transmit easily among humans.  

A(H9N2), China  

-- Since the last risk assessment of 29 September 2025, two cases of infection with influenza A(H9N2) were notified to WHO from China on 13 October 2025 in a child in Hunan province and an adult in Jiangxi province. The cases had onsets of symptoms in September 2025. Both had known exposure to backyard poultry. Both cases were detected through the influenza-like illness (ILI) surveillance system and have recovered. The adult case had underlying conditions and was hospitalized. No further cases were detected among contacts of these cases. 

-- A(H9) viruses were detected in environmental samples collected during the investigations around each case. 

Risk Assessment for avian influenza A(H9N2):   

-- 1. What is the global public health risk of additional human cases of infection with avian influenza A(H9N2) viruses?   

- Most human cases follow exposure to the A(H9N2) virus through contact with infected poultry or contaminated environments. Most human infections of A(H9N2) to date have resulted in mild clinical illness. Since the virus is endemic in poultry in multiple countries in Africa and Asia, further human cases associated with exposure to infected poultry are expected but remain unusual. The impact to public health if additional sporadic cases are detected is minimal. The overall global public health risk of additional sporadic human cases is low.  

-- 2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H9N2) viruses related to this event?   

- At the present time, no sustained human-to-human transmission has been identified associated with the recently reported human infections with A(H9N2) viruses. Current evidence suggests that A(H9N2) viruses from these cases did not acquire the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.   

-- 3. What is the likelihood of international spread of avian influenza A(H9N2) virus by travellers?   

- Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community level spread is considered unlikely as current evidence suggests the A(H9N2) virus subtype has not acquired the ability to transmit easily among humans.   

Overall risk management recommendations: 

-- Surveillance and investigations 

• Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global strategic surveillance in animals and humans to detect virologic, epidemiologic and clinical changes associated with circulating influenza viruses that may affect human (or animal) health. Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. Close collaboration with the animal health and environment sectors is essential to understand the extent of the risk of human exposure and to prevent and control the spread of animal influenza. WHO has published guidance on surveillance for human infections with avian influenza A(H5) viruses. 

• As the extent of influenza virus circulation in animals is not clear, epidemiologic and virologic surveillance and the follow-up of suspected human cases should continue systematically. Guidance on investigation of non-seasonal influenza and other emerging acute respiratory diseases has been published on the WHO website. 

• Countries should increase avian influenza surveillance in domestic and wild birds, enhance surveillance for early detection in cattle populations in countries where HPAI is known to be circulating, include HPAI as a differential diagnosis in non-avian species, including cattle and other livestock populations, with high risk of exposure to HPAI viruses; monitor and investigate cases in non-avian species, including livestock, report cases of HPAI in all animal species, including unusual hosts, to WOAH and other international organizations, share genetic sequences of avian influenza viruses in publicly available databases, implement preventive and early response measures to break the HPAI transmission cycle among animals through movement restrictions of infected livestock holdings and strict biosecurity measures in all holdings, employ good production and hygiene practices when handing animal products, and protect persons in contact with suspected/infected animals.{9} More guidance can be found from WOAH and FAO. 

• When there has been human exposure to a known outbreak of an influenza A virus in domestic poultry, wild birds or other animals – or when there has been an identified human case of infection with such a virus – enhanced surveillance in potentially exposed human populations becomes necessary. Enhanced surveillance should consider the health care seeking behaviour of the population, and could include a range of active and passive health care and/or communitybased approaches, including: enhanced surveillance in local influenza-like illness (ILI)/SARI systems, active screening in hospitals and of groups that may be at higher occupational risk of exposure, and inclusion of other sources such as traditional healers, private practitioners and private diagnostic laboratories. 

• Vigilance for the emergence of novel influenza viruses with pandemic potential should be maintained at all times including during a non-influenza emergency. In the context of the cocirculation of SARS-CoV-2 and influenza viruses, WHO has updated and published practical guidance for integrated surveillance. 

-- Notifying WHO 

• All human infections caused by a new subtype of influenza virus are notifiable under the International Health Regulations (IHR, 2005).{10} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed{11} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic{12}. Evidence of illness is not required for this report. Evidence of illness is not required for this report. 

• WHO published the case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005): https://www.who.int/teams/global-influenzaprogramme/avian-influenza/case-definitions. 

-- Virus sharing and risk assessment 

• It is critical that these influenza viruses from animals or from humans are fully characterized in appropriate animal or human health influenza reference laboratories. Under WHO’s Pandemic Influenza Preparedness (PIP) Framework, Member States are expected to share influenza viruses with pandemic potential on a timely basis{13} with a WHO Collaborating Centre for influenza of GISRS. The viruses are used by the public health laboratories to assess the risk of pandemic influenza and to develop candidate vaccine viruses.  

• The Tool for Influenza Pandemic Risk Assessment (TIPRA) provides an in-depth assessment of risk associated with some zoonotic influenza viruses – notably the likelihood of the virus gaining human-to-human transmissibility, and the impact should the virus gain such transmissibility. TIPRA maps relative risk amongst viruses assessed using multiple elements. The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA analyses will be published at http://www.who.int/teams/global-influenza-programme/avian-influenza/toolfor-influenza-pandemic-risk-assessment-(tipra).  

-- Risk reduction 

• Given the observed extent and frequency of avian influenza in poultry, wild birds and some wild and domestic mammals, the public should avoid contact with animals that are sick or dead from unknown causes, including wild animals, and should report dead birds and mammals or request their removal by contacting local wildlife or veterinary authorities.  

• Eggs, poultry meat and other poultry food products should be properly cooked and properly handled during food preparation. Due to the potential health risks to consumers, raw milk should be avoided. WHO advises consuming pasteurized milk. If pasteurized milk isn’t available, heating raw milk until it boils makes it safer for consumption. 

• WHO has published practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses. 

-- Trade and travellers 

• WHO advises that travellers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal excreta. Travelers should also wash their hands often with soap and water. All individuals should follow good food safety and hygiene practices.  

• WHO does not advise special traveller screening at points of entry or restrictions with regards to the current situation of influenza viruses at the human-animal interface. For recommendations on safe trade in animals and related products from countries affected by these influenza viruses, refer to WOAH guidance.  

Links:  

-- WHO Human-Animal Interface web page https://www.who.int/teams/global-influenza-programme/avian-influenza 

-- WHO Influenza (Avian and other zoonotic) fact sheet https://www.who.int/news-room/fact-sheets/detail/influenza-(avian-and-other-zoonotic) 

-- WHO Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases https://www.who.int/publications/i/item/WHO-WHE-IHM-GIP-2018.2 

-- WHO Public health resource pack for countries experiencing outbreaks of influenza in animals:  https://www.who.int/publications/i/item/9789240076884 

-- Cumulative Number of Confirmed Human Cases of Avian Influenza A(H5N1) Reported to WHO  https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-a-h5n1-virus 

-- Avian Influenza A(H7N9) Information https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-influenza-a-(h7n9)virus 

-- World Organisation of Animal Health (WOAH) web page: Avian Influenza  https://www.woah.org/en/home/ 

-- Food and Agriculture Organization of the United Nations (FAO) webpage: Avian Influenza https://www.fao.org/animal-health/avian-flu-qa/en/ 

-- OFFLU http://www.offlu.org/ 

____

{1} This summary and assessment covers information confirmed during this period and may include information received outside of this period. 

{2} For epidemiological and virological features of human infections with animal influenza viruses not reported in this assessment, see the reports on human cases of influenza at the human-animal interface published in the Weekly Epidemiological Record here.  

{3} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{4} Food and Agriculture Organization of the United Nations (FAO). Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential. 

{5} World Health Organization (2012). Rapid risk assessment of acute public health events. World Health Organization. Available at: https://iris.who.int/handle/10665/70810. 

{6} World Health Organization. Case definitions for the 4 diseases requiring notification to WHO in all circumstances under the International Health Regulations (2005). Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005).  

{7} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{8} Food and Agriculture Organization of the United Nations. Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential/bird-species-affected-by-h5nx-hpai/en. 

{9}World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024. Available at: https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/. 

{10} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005). 

{11} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011). Available at: https://apps.who.int/iris/handle/10665/44518. 

{12} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition. Available at: https://iris.who.int/handle/10665/341850. 

{13} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017). Available at: https://apps.who.int/iris/handle/10665/259402. 

Source: World Health Organization, https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--5-november-2025

____

First #assessment of #plague in terrestrial small #mammals and #fleas from Makira Natural Park and surroundings, North-eastern #Madagascar

 

Abstract

Background

Plague, a zoonosis caused by Yersinia pestis, is endemic in Madagascar but knowledge on the epidemiological situation in the northern focus remains unclear. The aim of this study was to investigate the circulation of Y. pestis in terrestrial small mammals in north eastern Madagascar, where suspected plague outbreaks have been reported.

Methods

Sampling of terrestrial small mammals and their fleas was carried out in 22 trapping sites within 9 localities of the two sectors (1 and 3) of Makira Natural Park (MNP) and surroundings, from 2020 to 2022. Yersinia pestis was investigated in terrestrial small mammal spleen samples and their fleas using bacteriological, serological and molecular methods.

Results

A total of 614 terrestrial small mammals composed of eight species and 1,754 individual fleas were collected following 4,880 trap-nights. The black rat (Rattus rattus) represented the majority (87.8%) of the small mammal species caught. Flea infestation rate was higher in sector 3 compared to sector 1. In sector 3, Xenopsylla brasiliensis, a plague vector, represented 66.4% of fleas identified. Further, one plague seropositive R. rattus individual, captured inside a house, and one Ctenocephalides felis specimen, collected on another R. rattus, was positive on PCR in this sector.

Discussion

Despite low detection rates, we confirmed the circulation of Y. pestis in our study area (one rat seropositive and one flea PCR positive) and highlight the risk of potential human transmission. Our results also suggest that R. rattus contributes to the maintenance and transmission of plague in MNP, as described for other areas in Madagascar. Further, these findings contribute to documentation of the known geographic distribution of the endemic plague vector S. fonquerniei and X. brasiliensis.

Conclusion

The confirmation of the circulation of the Y. pestis through serological and molecular diagnostics in small mammals and fleas underscores the urgent need to assess awareness levels of risk factors and symptoms to monitor among local communities and health workers and ensure that trained rapid response teams are prepared to intervene promptly upon suspect case detection. The risk and epidemiology of plague circulation in remote rural areas of Madagascar remains insufficiently studied. Addressing this gap is crucial, as a more comprehensive understanding of the distribution and dynamics of the wild animal hosts, their vectors and host-vector interactions will enhance risk assessment and prevention for plague emergence and improve mitigation and early control of potential outbreaks.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013710

____

#Poland - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

A slaughter turkeys operation in Kujawsko-Pomorskie Region.

Source: WOAH, https://wahis.woah.org/#/in-review/7012

____

#Germany - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

 

{Hessen Region}

laying hens (500), broilers (200), ducks for fattening (200), geese for fattening (700), turkeys for fattening (500)

Source: WOAH, https://wahis.woah.org/#/in-review/7021

____

#Portugal - High pathogenicity avian #influenza #H5 viruses (#poultry) (Inf. with) - Immediate notification

 

{Porto Region}

Small farm keeping 197 mixed species poultry and 187 captive birds of exotic species.

Source: WOAH, https://wahis.woah.org/#/in-review/7015

____

#Cambodia's #capital has reported its first #death from avian #influenza #H5N1 this year (Nov. 17 '25)

 

Phnom Penh, November 16 (Xinhua) -- Cambodia's Ministry of Health confirmed on the 16th that a young man residing in Phnom Penh had died from avian influenza (H5N1). Authorities urged the public to be vigilant and take effective preventative measures.

According to the report, the 22-year-old man experienced severe symptoms including fever, cough, shortness of breath, and difficulty breathing. Despite the medical team's best efforts, his condition rapidly deteriorated, and he died on the 15th of this month. This is the first reported human death from avian influenza in the country's capital this year.

Following the incident, the Cambodian Ministry of Health immediately activated its emergency response mechanism. Local professional teams are conducting a comprehensive and detailed epidemiological investigation to trace the source of infection and identify close contacts. To prevent further spread of the epidemic in the community, authorities have urgently allocated and distributed antiviral medications to the local population.

Cambodia has recorded 17 cases of human infection with the H5N1 avian influenza virus this year, including 6 deaths. Among the multiple avian influenza deaths reported since January, the youngest was a child who was only 2 years and 7 months old.

A Cambodian Ministry of Health official had previously warned that avian influenza continues to pose a serious threat to the lives and health of the Cambodian people. (End)

Source: China News Network, https://baijiahao.baidu.com/s?id=1848929739224488346&wfr=spider&for=pc

____

#Cambodia Man Dies from #H5N1 #Birdflu (Nov. 17 '25)

 

A 22-year-old Cambodian man died of H5N1 bird flu , the Ministry of Health said in a statement released Sunday, November 16, 2025, as reported by Xinhua and quoted by Antara.

"Laboratory results from the Cambodian National Institute of Public Health on November 15, 2025, showed that the man was positive for H5N1 virus infection," the Cambodian Ministry of Health said in a statement.

(...)

Source: Tempo, https://www.tempo.co/internasional/pria-kamboja-tewas-akibat-flu-burung-h5n1-2090146

____

Safety and immunogenicity of a #Nipah virus #vaccine (HeV-sG-V) in adults: a single-centre, randomised, observer-blind, placebo-controlled, phase 1 study

 

Summary

Background

First discovered in 1999 in Malaysia, Nipah virus (NiV) causes yearly outbreaks throughout south and southeast Asia with associated mortality rates of 40–75%. Due to the structural and sequence similarities between the NiV and Hendra virus (HeV) attachment G glycoproteins, and the extensive extant evidence of the ability of a recombinant soluble glycoprotein G (HeV-sG) to provide heterologous cross-protective immunity when used as vaccine (HeV-sG-V), this study aimed to evaluate HeV-sG-V for safety, tolerability, and immunogenicity against NiV.

Methods

We conducted a phase 1, single-centre, randomised, observer-blind, placebo-controlled study. Eligible participants were aged 18–49 years, healthy, and not pregnant; participants were ineligible if they were immunocompromised, had received blood products within 6 months of enrolment, had potential exposure to NiV or HeV, or had known allergies to components of the vaccine. Participants were randomly assigned in a 5:1 ratio to receive either one or two doses of the vaccine candidate (at 10 μg for the first cohort; 30 μg at days 1 and either days 8 or 29 for cohort 2; and 100 μg with the same timing for cohort 3) or placebo. The primary endpoints were solicited and unsolicited adverse events, clinically significant laboratory test result abnormalities, medically attended adverse events, and serious adverse events. Secondary endpoints were serum IgG binding via ELISA and neutralising antibody responses against prototypical NiV Bangladesh (NiVB) and NiV Malaysia (NiVM) reporter viruses.

Findings

Between Feb 24, 2020, and Oct 6, 2021, 268 participants were screened, and 192 were enrolled. 173 (90%) participants met the per-protocol criteria. Mild-to-moderate injection site pain was the most commonly reported adverse event. No serious adverse events, hospitalisations, or deaths were reported. The immune response to HeV-sG-V was dose-dependent; a single administration was not sufficiently immunogenic, whereas two administrations were immunogenic, with the highest response rates observed among vaccinees that received two administrations of the 100 μg HeV-sG-V 28 days apart (neutralising antibody geometric mean titres rose dramatically 7 days after the second investigational product dose, reaching 1485·6 (990·5–2228·1) and 2581·9 (147·1–3194·2) for NiVB and NiVM, respectively).

Interpretation

All three doses and regimens of HeV-sG-V had a tolerable risk profile and were able to induce an immune response. The induction of antibodies within 1 month of vaccination, along with the persistence afforded by two dosages, suggests the vaccine candidate has potential for reactive outbreak control and preventive use.

Funding

Coalition for Epidemic Preparedness Innovations (CEPI).

Source: The Lancet, https://www.sciencedirect.com/science/article/abs/pii/S014067362501390X?dgcid=rss_sd_all

____