Increase in Human Infections with Avian Influenza A(H7N9) Virus During the Fifth Epidemic — China, October 2016–February 2017

Iuliano, A. Danielle; Jang, Yunho; Jones, Joyce; Davis, C. Todd; Wentworth, David E.; Uyeki, Timothy M.; Roguski, Katherine; Thompson, Mark G.; Gubareva, Larisa V.; Fry, Alicia M.; Burns, Erin; Trock, Susan C.; Zhou, Suizan; Katz, Jacqueline M.; Jernigan, Daniel B.

doi:10.15585/mmwr.mm6609e2

Cited by 81 publications

(86 citation statements)

References 3 publications

(6 reference statements)

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“…Our study highlights the value of NA-specific antibodies in inhibiting replication of the novel A(H7N9) virus, especially in light of antigenic changes that have occurred in the HA of A(H7N9) viruses (41). Both HA and NA of influenza viruses experience antigenic drift; however, there is discordance in their evolution (42), and NA tends to evolve at a lower rate (43,44).…”

Section: Discussionmentioning

confidence: 75%

Comparison of the Efficacy of N9 Neuraminidase-Specific Monoclonal Antibodies against Influenza A(H7N9) Virus Infection

Wan

Gao

et al. 2018

J Virol

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The fifth wave of A(H7N9) virus infection in China from 2016 to 2017 caused great concern due to the large number of individuals infected, the isolation of drug-resistant viruses, and the emergence of highly pathogenic strains. Antibodies against neuraminidase (NA) provide added benefit to hemagglutinin-specific immunity and may be important contributors to the effectiveness of A(H7N9) vaccines. We generated a panel of mouse monoclonal antibodies (MAbs) to identify antigenic domains on NA of the novel A(H7N9) virus and compared their functional properties. The loop formed in the region of residue 250 (250 loop) and the domain formed by the loops containing residues 370, 400, and 430 were identified as major antigenic regions. MAbs 1E8, 2F6, 10F4, and 11B2, which recognize these two antigenic domains, were characterized in depth. These four MAbs differ in their abilities to inhibit cleavage of small and large substrates (methyl-umbelliferylacetyl neuraminic acid [MU-NANA] and fetuin, respectively) in NA inhibition assays. 1E8 and 11B2 did not inhibit NA cleavage of either MU-NANA or fetuin, and 2F6 inhibited cleavage of fetuin alone, whereas 10F4 inhibited cleavage of both substrates. All four MAbs reduced the in vitro spread of viruses carrying either the wild-type N9 or N9 with antiviral-resistant mutations but to different degrees. These MAbs have different in vivo levels of effectiveness: 10F4 was the most effective in protecting mice against challenge with A(H7N9) virus, 2F6 was less effective, and 11B2 failed to protect BALB/c mice at the doses tested. Our study confirms that NA-specific antibodies can protect against A(H7N9) infection and suggests that in vitro properties can be used to rank antibodies with therapeutic potential. IMPORTANCEThe novel A(H7N9) viruses that emerged in China in 2013 continue to infect humans, with a high fatality rate. The most recent outbreak resulted in a larger number of human cases than previous epidemic waves. Due to the absence of a licensed vaccine and the emergence of drug-resistant viruses, there is a need to develop alternative approaches to prevent or treat A(H7N9) infection. We have made a panel of mouse monoclonal antibodies (MAbs) specific for neuraminidase (NA) of A(H7N9) viruses; some of these MAbs are effective in inhibiting viruses that are resistant to antivirals used to treat A(H7N9) patients. Binding avidity, inhibition of NA activity, and plaque formation correlated with the effectiveness of these MAbs to protect mice against lethal A(H7N9) virus challenge. This study identifies in vitro measures that can be used to predict the in vivo efficacy of NA-specific antibodies, providing a way to select MAbs for further therapeutic development.

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Section: Discussionmentioning

confidence: 75%

Comparison of the Efficacy of N9 Neuraminidase-Specific Monoclonal Antibodies against Influenza A(H7N9) Virus Infection

Wan

Gao

et al. 2018

J Virol

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“…Avian influenza viruses of the H7N9 subtype recently emerged in China and have the potential to cause global pandemics if they acquire the ability to transmit human to human (2). As of February 2017, there have been 1,258 reported human cases of H7N9 avian influenza, with a case fatality rate of 41%, primarily due to rapidly progressing pneumonia (3). During the fifth epidemic of human H7N9 avian influenza (beginning on October 1, 2016), there has been a dramatic rise in the number of cases reported (460 cases) compared with the previous 4 epidemics, suggesting that H7N9 avian influenza poses an ongoing threat to human health.…”

Section: Introductionmentioning

confidence: 99%

Fc functional antibodies in humans with severe H7N9 and seasonal influenza

Vanderven¹,

Liu²,

Ana-Sosa-Batiz³

et al. 2017

JCI Insight

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“…The sudden increase in the number of H7N9 cases during the fifth wave raises global concern 8, 9, 12. The national study showed that the main epidemiological characteristics remained unchanged 9, 10.…”

Section: Discussionmentioning

confidence: 99%

“…To control its impact, temporary or permanent closure of live poultry markets has been implemented by many local governments, leading to a declining trend of laboratory‐confirmed cases in the first four waves 7, 8, 9, 10, 11. However, an unprecedented outbreak of human infection with avian influenza A(H7N9) virus, identified as the fifth wave, occurred in China from September 2016, and a number of cases reported in the fifth wave exceeded those reported in the previous waves in China 8, 9, 10, 12…”

Section: Introductionmentioning

confidence: 99%

Comparison of the three waves of avian influenza A(H7N9) virus circulation since live poultry markets were permanently closed in the main urban areas in Zhejiang Province, July 2014‐June 2017

Cheng

Wang

Shen

et al. 2018

Influenza Resp Viruses

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BackgroundThe sudden increase in the number of human cases infected with avian influenza A(H7N9) virus after September 2016 raised global concern.ObjectivesTo assess the changes in epidemiological characteristics of H7N9 cases since the massive closure of live poultry markets (LPMs) in the main urban areas in Zhejiang province.MethodsWe used descriptive statistics to compare epidemiological characteristics of the three distinct waves of H7N9 cases in Zhejiang province. The rural or urban cases were defined according to the location where the patients had exposure within 2 weeks before illness onset.ResultsBetween July 2014 and June 2017, 166 H7N9 cases were reported in Zhejiang province, with 45, 34, and 87 cases reported in the third, fourth, and fifth wave, respectively. Across the three waves, most reported cases were from rural areas. A similar percentage of cases in all three waves reported exposure to LPMs, raising poultry at home or around the house, as well as occupational exposure. Compared to the third (80.00%) and fourth wave (70.59%), a significantly larger proportion of cases from the non‐LPMs closure areas were observed in the fifth wave (89.66%) (P = .034).ConclusionEpidemiological characteristics of human cases infected with avian influenza A(H7N9) virus had generally remained unchanged since the massive closure of LPMs in the main urban area of Zhejiang province. The sudden increase in the number of H7N9 cases in the fifth wave was mainly attributed to the excessive cases reported from areas where LPMs were not permanently closed.

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Increase in Human Infections with Avian Influenza A(H7N9) Virus During the Fifth Epidemic — China, October 2016–February 2017

Cited by 81 publications

References 3 publications

Comparison of the Efficacy of N9 Neuraminidase-Specific Monoclonal Antibodies against Influenza A(H7N9) Virus Infection

Comparison of the Efficacy of N9 Neuraminidase-Specific Monoclonal Antibodies against Influenza A(H7N9) Virus Infection

Fc functional antibodies in humans with severe H7N9 and seasonal influenza

Comparison of the three waves of avian influenza A(H7N9) virus circulation since live poultry markets were permanently closed in the main urban areas in Zhejiang Province, July 2014‐June 2017

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