The #consequences of letting avian #influenza run rampant in #US #poultry

Abstract

As of 20 May, the US Department of Agriculture (USDA) has confirmed highly pathogenic avian influenza (HPAI) in more than 173.1 million birds since the outbreak began in January 2022. The secretary of the US Department of Health and Human Services, Robert Kennedy Jr., has suggested allowing the unmitigated spread of HPAI in turkeys and chickens to identify surviving birds—a sentiment supported by Brooke Rollins, secretary of the USDA, which, along with state-level departments of agriculture, has jurisdiction over animal disease outbreaks (1). This approach would be dangerous and unethical. Allowing a highly lethal, rapidly evolving, and contagious virus to run a natural course of infection in poultry would lead to unnecessary suffering of poultry and put other susceptible animals on and near affected farms at risk. It would prolong exposure for farmworkers, which could increase viral adaptation and transmission risks for poultry, other peridomestic animals, and humans.

Source: Science, https://www.science.org/doi/10.1126/science.adx8639

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Analysis of the #surveillance results of avian #influenza in the external #environment of #Huzhou city from 2017 to 2023

Abstract

Background

Avian influenza is an infectious disease of birds caused by the influenza A virus, which can infect a variety of domestic,wild birds and even cross the species barrier and infect humans.To understand the contamination of avian influenza virus in the external environment of poultry in Huzhou City from 2017 to 2023 and to assess the risk of human infection with avian influenza.

Methods

A total of 3,400 environmental specimens from five types of venues in Huzhou City were collected and tested for influenza A virus nucleic acid using fluorescent reverse transcription polymerase chain reaction (RT-PCR).

Results

From 2017 to 2023, with 15.44% overall positive rate of influenza A virus. The predominant subtype of avian influenza virus was H9 (accounting for 54.67%). The peak of positive influenza virus detection rates occurred in winter and spring seasons every year. The venue with highest positive rate was poultry slaughtering and processing plants (41.83%), followed by urban and rural live poultry markets (35.48%); among all types of specimens, the highest positive rate was detected in swab specimens from the surfaces of poultry slaughtering or display tables (47.37%), followed by wastewater from poultry washing (45.83%), and surfaces of cages (27.65%).

Conclusion

The contamination of avian influenza virus in the poultry environment in Huzhou City is relatively severe, with diverse subtypes. There is a potential risk of human infection with avian influenza virus, and real-time monitoring of avian influenza virus in the poultry environment needs to be strengthened.

Source: PLoS One, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0326382

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Notes from the Field: #Parvovirus B19 #Activity — #USA, January 2024–May 2025 (MMWR)

Summary

-- What is already known about this topic?

- Parvovirus B19 (B19) is a respiratory virus that can cause adverse fetal outcomes in pregnant women and persons who are immunocompromised or have chronic hemolytic blood disorders. After relatively low rates during the COVID-19 pandemic years of 2021–2023, B19 activity in 2024 exceeded that of prepandemic years.

-- What is added by this report?

- Data from the National Syndromic Surveillance Program indicated that the proportion of sera specimens positive for B19 antibodies during January–May 10, 2025, was higher than during the same period in 2024, suggesting a sustained increase in B19 transmission.

-- What are the implications for public health practice?

- Health care providers should have a heightened suspicion of and consider providing testing for B19 infection among groups at high risk for severe outcomes, including pregnant women with compatible symptoms or exposure to B19. Among pregnant women, health care providers should remain vigilant for fetal complications related to B19 infection. Pregnant women and persons at increased risk for complications from B19 infection might consider using additional prevention strategies (e.g., wearing a mask around other persons).

Abstract

Parvovirus B19 (B19) is a respiratory virus primarily transmitted through the air by persons with symptomatic or asymptomatic infection. B19 infection causes mild illness in most persons but can result in adverse fetal outcomes in pregnant women or severe disease in persons who are immunocompromised or have chronic hemolytic blood disorders. No antiviral medication exists to treat B19 infection. B19 activity typically peaks in the second quarter of the year (April–June). After low rates during the COVID-19 pandemic (2021–2023), B19 activity in 2024 exceeded prepandemic years, and CDC released a Health Advisory in August 2024 (1,2).

Source: US Centers for Disease Control and Prevention, http://dx.doi.org/10.15585/mmwr.mm7423a3

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Little #boy in SW #Cambodia becomes 12th victim of #H5N1 #birdflu in 2025

 

PHNOM PENH, July 3 (Xinhua) -- A five-year-old boy from southwest Cambodia's Kampot province has been confirmed for H5N1 human avian influenza, bringing the number of cases to 12 so far this year, the Ministry of Health said in a statement on Thursday.

"A laboratory result from the National Institute of Public Health showed on July 3 that the boy was positive for H5N1 virus," the statement said. "The patient has the symptoms of fever, cough, and dyspnea, and he is currently being rescued by a team of doctors."

The victim lives in Kamakor village of Angkor Chey district. 

Source: Xinhua, https://english.news.cn/asiapacific/20250703/a96b269ca29f41238c41884f8b390782/c.html

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#India - #Equine #influenza #H3N8 virus (Inf. with) - Immediate notification

 Domestic equidae species in Uttarakhand State.

Source: WOAH, https://wahis.woah.org/#/in-review/6441

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An ancient #influenza #genome from #Switzerland allows deeper #insights into host #adaptation during the 1918 flu #pandemic in #Europe

Abstract

Background

From 1918 to 1920, the largest influenza A virus (IAV) pandemic known to date spread globally causing between 20 to 100 million deaths. Historical records have captured critical aspects of the disease dynamics, such as the occurrence and severity of the pandemic waves. Yet, other important pieces of information such as the mutations that allowed the virus to adapt to its new host can only be obtained from IAV genomes. The analysis of specimens collected during the pandemic and still preserved in historical pathology collections can significantly contribute to a better understanding of its course. However, efficient RNA processing protocols are required to work with such specimens.

Results

Here, we describe an alternative protocol for efficient ancient RNA sequencing and evaluate its performance on historical samples, including a published positive control. The phenol/chloroform-free protocol efficiently recovers ancient viral RNA, especially small fragments, and maintains information about RNA fragment directionality through incorporating fragments by a ligation-based approach. One of the assessed historical samples allowed for the recovery of the first 1918 IAV genome from Switzerland. This genome, derived from a patient deceased during the beginning of the first pandemic wave in Switzerland, already harbours mutations linked to human adaptation.

Conclusion

We introduce an alternative, efficient workflow for ancient RNA recovery from formalin-fixed wet specimens. We also present the first precisely dated and complete influenza genome from Europe, highlighting the early occurrence of mutations associated with adaptation to humans during the first European wave of the 1918 pandemic.

Source: BMC Biology, https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-025-02282-z

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Development of a broad-spectrum #subunit #vaccine against #H9N2 avian #influenza using HA stem domain scaffold and snoopligase system

Abstract

H9N2 avian influenza virus (AIV) is a globally prevalent pathogen that causes economic losses in poultry and poses zoonotic threats. Due to antigenic drift and shift, traditional inactivated vaccines often show reduced efficacy. This study presents a novel subunit vaccine based on a conserved HA6 scaffold derived from the hemagglutinin stem domain and coupled with a fusion peptide epitope (fPE) via Snoopligase-mediated ligation. The HA6 protein was validated by its binding to the broad-spectrum antibody CR6261, and the fPE-HA6 fusion construct incorporated T- and B-cell epitopes. Immunization trials in a chicken demonstrated that fPE-HA6 induced stronger humoral and cellular immune responses than individual immunogens. Upon challenge with H9N2 strains YZ4 and SN, the fusion vaccine significantly reduced viral shedding, demonstrating broad-spectrum protection. These findings highlight the potential of HA6 as a modular scaffold for influenza vaccines and the utility of Snoopligase technology in developing broadly protective immunogens against antigenically variable viruses.

Source: npj Vaccines, https://www.nature.com/articles/s41541-025-01191-0

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Introducing a #framework for within-host dynamics and #mutations #modelling of #H5N1 #influenza #infection in #humans

Abstract

Avian influenza A(H5N1) poses a public health risk due to its pandemic potential should the virus mutate to become human-to-human transmissible. To date, reported influenza A(H5N1) human cases have typically occurred in the lower respiratory tract with a high case fatality rate. There is prior evidence of some influenza A(H5N1) strains being a small number of amino acid mutations away from achieving droplet transmissibility, possibly allowing them to be spread between humans. We present a mechanistic within-host influenza A(H5N1) infection model, novel for its explicit consideration of the biological differences between the upper and lower respiratory tracts. We then estimate a distribution of viral lifespans and effective replication rates in human H5N1 influenza cases. By combining our within-host model with a viral mutation model, we determine the probability of an infected individual generating a droplet transmissible strain of influenza A(H5N1) through mutation. For three mutations, we found a peak probability of approximately 10−3 that a human case of H5N1 influenza produces at least one virion during the infectious period. Our findings provide insights into the risk of differing infectious pathways of influenza A(H5N1) (namely avian–human versus avian–mammal–human routes), demonstrating the three-mutation pathway being a cause of concern in human cases.

Source: Proceedings of the Royal Society Interface, https://royalsocietypublishing.org/doi/10.1098/rsif.2024.0910

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Increase in #H5N1 #vaccine #antibodies confers cross-neutralization of highly pathogenic avian #influenza H5N1

Abstract

H5N1, a highly pathogenic avian influenza virus, presents pandemic risks due to its ability to adapt and spread among mammalian species. Vaccination may control its spread, but the effectiveness of existing H5N1 vaccines against circulating strains, especially clade 2.3.4.4b, remains uncertain. In this study, we assess neutralizing antibody responses to global circulating H5N1 strains, using sera from individuals vaccinated with an inactivated H5N1 vaccine (NCT00535665). Neutralization is measured against 17 pseudoviruses, representing circulating and vaccine H5 strains. Our results indicate that broad protective effects are observed only when high antibody titers are achieved by vaccination. Correlation analysis estimates that a pseudovirus-based neutralization titer of at least 1:980 is required to achieve a cross-protection rate above 60%. The findings suggest that the current H5N1 vaccine can elicit cross-neutralization of circulating H5N1 strains, if high antibody titers are achieved. Until updated H5N1 vaccines are developed, this vaccine may serve as a bridging measure.

Source: Nature Communications, https://www.nature.com/articles/s41467-025-60714-4

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Weak #compliance with #Nigeria’s #wildlife #trade ban imposed to curb #mpox #spillovers

Abstract

Zoonotic diseases pose global public health threats, prompting various interventions to limit their emergence and spread. One increasingly common response by governments has been to ban wildlife hunting, trade and consumption. However, there is limited evidence of the effectiveness of wildlife trade bans. Here we assess compliance with Nigeria’s wildlife trade ban—enacted to curb the spread of mpox (formerly monkeypox)—by analysing approximately 4.5 years of wild meat sales data from 19 vendors in southeast Nigeria (988 vendor-months) alongside interviews with vendors and law enforcement officials. After matching the sales data by time of year, we found no significant differences before and after the ban in the number of vendors selling wild meat per week, the weekly mass of wild meat sold, or the weekly price per kilogram of wild meat; however, the total weekly sales price was higher post-ban. These findings, supported by interview insights, indicate widespread non-compliance by vendors, questioning the ban’s effectiveness. We propose that successful regulations require clear enforcement mechanisms, active public engagement and economic incentives to improve compliance. This study provides valuable insights for designing effective interventions to mitigate zoonotic spillovers.

Source: Proceedings of the Royal Society, Biological Sciences, https://royalsocietypublishing.org/doi/full/10.1098/rspb.2025.0471

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Structural and functional characterization of the #antigenicity of #influenza A virus #hemagglutinin subtype #H15

Abstract

Avian H15 influenza viruses are closely related to H7 viruses, but feature a unique 9-amino acid insertion in their hemagglutinin head domain, creating an additional site for antigenic variation. Here, we characterized a panel of mouse monoclonal antibodies (mAbs) raised against the A/wedge-tailed shearwater/Western Australia/2576/1979 ancestral strain, and a human mAb isolated from an H7N9 vaccinee. We found differences in binding and neutralization profiles against the ancestral strain and drifted strains of H15 isolated after 2008. MAbs that have hemagglutination inhibition activity against the ancestral strain do not show binding to drifted strains, hinting at antigenic differences in the receptor binding site. We show that the mAbs protect in vivo and elucidate mAb-antigen interactions using negative stain and cryo-electron microscopy. The characterization of H15 antigenicity and mechanisms of antibody-mediated neutralization expands our knowledge of this rare avian influenza virus and informs our understanding of immune pressures on viral surface glycoproteins.

Source:  BioRxIV, https://www.biorxiv.org/content/10.1101/2025.07.01.662631v1?rss=1

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

Two poultry farms affected in North West and Mpumalanga Regions.

Source: WOAH, https://wahis.woah.org/#/in-review/6585?reportId=175014&fromPage=event-dashboard-url

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#Influenza A Virus #infection is associated with TDP-43 #pathology and neuronal #damage in the #brain

Abstract

Viral pandemics such as COVID-19 have demonstrated long-term neurological consequences, including memory impairment and depression, emphasizing the importance of understanding virus-brain interactions [1]. Similar concerns have been raised for Influenza A virus (IAV), which has been implicated in neurodegenerative disorders [2, 3]. In this study, we investigated the neuropathological effects of highly pathogenic avian influenza (HPAI) H5N1 and H5N8 strains in a mouse model. Although viral RNA was detected in the brain post-infection, no viral proteins were found, suggesting limited or transient brain replication. Despite this, infected brains showed significant neuronal damage, including axonal loss and nuclear condensation, as evidenced by immunofluorescence and Nissl staining. We also observed pathological changes in TDP-43, including conformational alterations and increased phosphorylation, which required antigen retrieval for detection, features reminiscent of those found in frontotemporal dementia and amyotrophic lateral sclerosis [4, 5]. Transcriptomic analysis further revealed strain-specific host responses, including activation of interferon-related genes and downregulation of microtubule-associated pathways. These findings suggest that IAV infection can trigger hallmarks of neurodegeneration in the absence of persistent viral protein expression, possibly through host-driven mechanisms. Our results underscore the need for further investigation into virus-induced molecular pathways contributing to neurodegenerative disease.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.06.30.662477v1

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A 15-year study of #neuraminidase #mutations and the increasing of S247N mutation in #Spain

Highlights

• In a landscape of a very narrow arsenal of influenza antivirals, resistance mutations are a significant threat.

• Resistance mutations were present in 0.5-5% in A and B influenza viruses during the last 15 years.

• However, S247N resistance mutation in the NA gene sharply increased during 2023-2024 season.

• While this mutation does not confer strong resistance by itself, their fixation could increase the risk of resistance in the future if other resistance mutations appears or get fixed together with it.

Abstract

The therapeutic arsenal against influenza is extremely limited and resistance often arises due to the emergence of mutations, especially in the neuraminidase (NA) gene. This study aimed to evaluate the evolution of NA mutations over 15 years in Spain. To do so, we used the GISAID database from which we downloaded a total of 11,125 influenza A(H1N1)pdm09, A(H3N2), B/Victoria and B/Yamagata NA virus sequences, and analyzed the resistance mutations using FluSurver software. Our results showed that the occurrence of NA resistance mutations remained constant in the four viruses during the 15 seasons evaluated, being around 0.5-5%. Most of the resistance was found in the A(H1N1)pdm09 subtype (around 70%), especially from the 2023-2024 season onwards, when a significant increase in the occurrence of S247N mutation was observed. The occurrence of this type of mutation before 2022 was rare, but in the 2023-2024 season a total of 44 influenza viruses harboring S247N mutations were detected, while in the other years, only two cases were observed. Some studies have described a significant increase in this mutation over the past two seasons and although it appears to confer only slightly reduced inhibition to oseltamivir, its increase is noteworthy and should be a reason for increased their vigilance.

Source: Virus Research, https://www.sciencedirect.com/science/article/pii/S0168170225000760?via%3Dihub

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A single-dose #intranasal #immunization with a novel #bat #influenza A virus-vectored #MERS #vaccine provides effective protection against lethal MERS-CoV challenge

ABSTRACT

The threat to global health security posed by Middle East respiratory syndrome coronavirus (MERS-CoV) and emerging MERS-like coronaviruses highlights the need to develop safe and efficient vaccines. Viral vector vaccines have been shown to be effective and are widely used to prevent various viral diseases because they mimic natural infection and induce a more comprehensive immune response. Herein, we developed a novel bat influenza A virus-based vaccine vector by replacing the open reading frame of either bat influenza hemagglutinin or neuraminidase with that of the hemagglutinin-esterase-fusion gene from influenza D virus, which can infect multiple species, including humans and camels. We then generated a temperature-sensitive, cold-adapted, and attenuated MERS vaccine candidate expressing the clade A MERS-CoV spike S1, referred to as Len_S1, using the developed bat influenza vector and demonstrated its safety and immunogenicity. A single-dose intranasal immunization with Len_S1 protected human dipeptidyl-peptidase-4 (hDPP4) transgenic mice from a lethal MERS-CoV challenge. Notably, a two-dose immunization with Len_S1 completely blocked viral replication and lung damage in challenged mice. Further studies revealed that intranasal immunization with Len_S1 in mice elicited mucosal, humoral, and cellular immune responses. Moreover, sera collected from Len_S1-immunized mice were able to cross-neutralize multiple clades of MERS-CoVs. Collectively, these results indicate that Len_S1 is a safe and effective MERS vaccine that induces a comprehensive immune response and provides cross-protection against diverse clades of MERS-CoVs.

Source: mBio, https://journals.asm.org/doi/10.1128/mbio.01107-25

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#Genetic #resilience or #resistance in #poultry against avian #influenza virus: mirage or reality?

ABSTRACT

The unprecedented global spread of the highly pathogenic avian influenza (HPAI) virus in wild birds, poultry, and mammalian species has challenged our control efforts. Alternative approaches to limit avian influenza viruses (AIV) include the development of resilient or resistant chickens. Genetically resilient birds may become infected but can overcome disease, whereas resistant birds prevent virus attachment or entry and do not become infected. The most intensively studied host gene is myxovirus-resistance (Mx), which is expressed via the interferon pathway. Both sensitive and resistant chicken Mx genotypes have been described, but this only provides limited resilience. Acidic nuclear phosphoprotein 32 family member A (ANP32A) has been demonstrated as a host cofactor for AIV replication via interaction with the polymerase. Small nucleotide changes within this gene have demonstrated some promise for the establishment of disease resilience. Certain MHC-defined genetic chicken lines have demonstrated increased resilience with higher innate immune responses, but HPAI-infected birds still have high morbidity and mortality. Alternatively, gene-edited or -transgenic chickens have had some success in increasing resilience. This strategy allows flexibility to include foreign genes, modification of existing genes, or combined approaches to block critical steps in the viral life cycle. Some candidate genes include solute carrier 35A1 (SLC35A1), retinoic acid-inducible gene I (RIG-I), and toll-like receptors 3 and 7 (TLR3/7), but animal testing needs to be conducted. Furthermore, existing hurdles for technology transfer to commercial application from either naturally occurring resistance genes or foreign genes remain high and will require acceptance by both the poultry industry and consumers.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.00820-25?af=R

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#Cambodia records 11th #human case of #H5N1 #birdflu in 2025

 

PHNOM PENH, July 1 (Xinhua) -- A 36-year-old woman from northwest Cambodia's Siem Reap province has been confirmed for H5N1 human avian influenza, raising the number of the cases to 11 so far this year, the Ministry of Health said in a statement on Tuesday.

"A laboratory result from the Pasteur Institute in Cambodia showed on June 30 that the woman was positive for H5N1 virus," the statement said. "The patient has the symptoms of fever, cough, and dyspnea, and she is currently being rescued by a team of doctors."

The victim lives in Doun Keo village of Puok district.

There were sick and dead chickens at the patient's home. She had been in contact with those dead chickens and took them to bury.

Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak in the community.

Tamiflu (oseltamivir), an antiviral drug to prevent the bird flu from spreading, was also given out to people who had direct contact with the patient, the statement said.

So far this year, the kingdom recorded a total of 11 human cases of H5N1 bird flu, with five deaths, according to the Ministry of Health.

Source: Xinhua, https://english.news.cn/asiapacific/20250701/82062615bf9a44b1933b4dc3535823fb/c.html

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#Cambodia reported four additional #human cases of #infection with #influenza A #H5N1 virus during week 26/2025 (HK CPH, July 1 '25)

 

{Excerpt}

[Date of report - Country - Province / Region - District - City - Sex - Age - Condition at time of reporting  - Subtype of virus] 

1) 24/06/2025 - Cambodia - Siem Reap province  - F - 41 - Critical  - H5N1 

2) 29/06/2025 - Cambodia - Siem Reap province  - F - 46 - Stable - H5N1 

3) 29/06/2025 - Cambodia - Siem Reap province  - M - 16 - Stable - H5N1 

4) 30/06/2025 - Cambodia - Takeo province - M - 19 months  - Deceased - H5N1 

(...)

Source: Centre for Health Protection, Hong Kong PRC SAR, https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk26.pdf

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#Monkeypox virus spreads from #cell-to-cell and leads to #neuronal #death in human neural #organoids

Abstract

In 2022-23, the world witnessed the largest recorded outbreak of monkeypox virus (MPXV). Neurological manifestations were reported alongside the detection of MPXV DNA and MPXV-specific antibodies in the cerebrospinal fluid of patients. Here, we analyze the susceptibility of neural tissue to MPXV using human neural organoids (hNOs) exposed to a clade IIb isolate. We report susceptibility of several cell types to the virus, including neural progenitor cells and neurons. The virus efficiently replicates in hNOs, as indicated by the exponential increase of infectious viral titers and establishment of viral factories. Our findings reveal focal enrichment of viral antigen alongside accumulation of cell-associated infectious virus, suggesting viral cell-to-cell spread. Using an mNeonGreen-expressing recombinant MPXV, we confirm cell-associated virus transmission. We furthermore show the formation of beads in infected neurites, a phenomenon associated with neurodegenerative disorders. Bead appearance precedes neurite-initiated cell death, as confirmed through live-cell imaging. Accordingly, hNO-transcriptome analysis reveals alterations in cellular homeostasis and upregulation of neurodegeneration-associated transcripts, despite scarcity of inflammatory and antiviral responses. Notably, tecovirimat treatment of MPXV-infected hNOs significantly reduces infectious virus loads. Our findings suggest that viral disruption of neuritic transport drives neuronal degeneration, potentially contributing to MPXV neuropathology and revealing targets for therapeutic intervention.

Source: Nature Communications, https://www.nature.com/articles/s41467-025-61134-0

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The Lookout – "All's Well", Winslow Homer (1896)

 

Public Domain.

Source: WikiArt, https://www.wikiart.org/en/winslow-homer/the-lookout-alls-well-1896

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