Safety and #effectiveness of MVA-BN #vaccination against #mpox in at-risk individuals in #Germany (SEMVAc and TEMVAc): a combined prospective and retrospective cohort study

Summary

Background

More than 115 000 cases of mpox have been confirmed since the onset of a global outbreak in 2022. In addition to global transmission of clade II monkeypox virus (MPXV), the recent spread of clade I has caused a Public Health Emergency of International Concern. The third-generation smallpox vaccine modified vaccinia Ankara–Bavarian Nordic (MVA-BN) was recommended for at-risk populations in 2022, despite a scarcity of data on safety and effectiveness against mpox.

Methods

We did a prospective, multicentre, observational study, enrolling men who have sex with men and transgender people aged 18 years or older with changing sexual partners in Germany (Safety and Effectiveness of MVA-BN Vaccination Against MPXV Infection [SEMVAc]) between July 7, 2022, and Dec 31, 2023, evaluating safety and reactogenicity of one and two doses of subcutaneous MVA-BN. Vaccine effectiveness was estimated using risk ratios from the Kaplan–Meier estimator in an emulated retrospective target trial (Emulated Target Trial for Effectiveness of MVA-BN Vaccination Against mpox Infection in At-risk Individuals [TEMVAc]) from 3027 vaccinated individuals matched (1:1) to 3027 unvaccinated controls. SEMVAc and TEMVAc were registered in the HMA-EMA Catalogue, EUPAS50093, and the German Clinical Trials Register, DRKS00029638, and are complete.

Findings

6459 individuals were prospectively enrolled in SEMVAc. Adverse reactions were infrequent (first dose: 0·35% [95% CI 0·20–0·60] and second dose: 0·14% [0·06–0·33]). Local reactions were more frequent after the first dose (70·2% [95% CI 68·5–71·8]) compared with the second dose (56·8% [54·6–59]), as were systemic reactions (first dose, 22·3% [95% CI 20·9–23·9]; second dose, 17·6% [15·9–19·4]). In TEMVAc, 16 mpox cases were reported in vaccinated individuals versus 32 cases in matched unvaccinated individuals (median follow-up 55 days [IQR 23–89]). Effectiveness by 14 days or later after one dose was 57·8% (95% CI 11·8 to 83·0) overall, 84·1% (42·0 to 100) in people without HIV, but 34·9% (–72·8 to 79·0) in people living with HIV. Breakthrough infections were associated with reduced symptoms, compared with infections in unvaccinated individuals.

Interpretation

MVA-BN vaccination was safe and well tolerated. One dose of MVA-BN offered protection against mpox but effectiveness was reduced in people living with HIV. Although randomised controlled trials remain the preferred approach for assessing vaccine efficacy, combining prospective and retrospective study designs can be valuable during dynamic public health emergencies.

Source: The Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00018-0/fulltext?rss=yes

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#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...

Stability of #influenza viruses in the #milk of #cows and #sheep

Abstract In late 2023, H5N1 high pathogenicity avian influenza (HPAIV) started circulating in dairy cattle in the USA . High viral titres were detected in milk from infected cows , raising concerns about onwards human infections . Although pasteurisation was shown to effectively inactivate influenza viruses in milk, unpasteurised milk still poses a risk of infection, both from occupational exposure in dairies and from the consumption of raw milk. We therefore assessed how long influenza viruses could remain infectious for in milk without heat inactivation. We examined the stability of a panel of influenza viruses in milk , including a contemporary H5N1 HPAIV and a variety of other influenza A and D viruses. We incubated viruses in cows' milk under laboratory conditions : at room temperature to simulate exposure in dairies and at 4°C to simulate exposure to refrigerated raw milk. Following an isolated report of H5N1 viral RNA being detected in milk from a sheep in the UK , we also c...

#Evidence of #Viremia in Dairy #Cows Naturally Infected with #Influenza A {#H5N1} Virus, #California, #USA

Abstract We confirmed influenza A virus (IAV) by PCR in serum from 18 cows on 3 affected dairy farms in California, USA . Our findings indicate the presence of viremia and might help explain IAV transmission dynamics and shedding patterns in cows. An understanding of those dynamics could enable development of IAV mitigation strategies. Source: US Centers for Disease Control and Prevention, https://wwwnc.cdc.gov/eid/article/31/7/25-0134_article ____

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