tetano
Editor, Senior Moderator
J Infect Dis. 2018 May 12. doi: 10.1093/infdis/jiy291. [Epub ahead of print]
[h=1]Population Serologic Immunity to human and avian H2N2 viruses in the United States and Hong Kong for Pandemic Risk Assessment.[/h] Babu TM[SUP]1[/SUP], Perera R[SUP]2[/SUP], Wu JT[SUP]2[/SUP], Fitzgerald T[SUP]1[/SUP], Nolan C[SUP]1[/SUP], Cowling BJ[SUP]2[/SUP], Krauss S[SUP]3[/SUP], Treanor JT[SUP]1[/SUP], Peiris M[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]Introduction:[/h] Influenza A pandemics cause significant mortality and morbidity. H2N2 viruses have caused prior pandemic, and are circulating in avian reservoirs. The age-related frequency of current population immunity to H2 viruses was evaluated.
[h=4]Methods:[/h] Hemagglutinin inhibition (HAI) assays against historical human and recent avian influenza A (H2N2) viruses were performed across age groups in Rochester, NY and Hong Kong, China. The impact of existing cross-reactive HAI immunity on the effective reproductive number(R) was modeled.
[h=4]Results:[/h] 150 individual sera from Rochester and 295 from Hong Kong were included. 85% born in Rochester and Hong Kong before 1968 had HAI titers >1:40 against A/Singapore/1/57, and over 50% had titers >1:40 against A/Berkeley/1/68. The frequency of titers ≥1:40 to avian H2N2 A/Mallard/England/727/06 and A/Mallard/Netherlands/14/07 in subjects born before 1957 was 62% and 24%. There were no H2 HAI titers >1:40 in individuals born after 1968. These levels of seroprevalence reduce the initial R of A/Singapore/1/1957 or A/Berkeley/1/68 by 15%-20%. A basic reproductive number (R0) of the emerging transmissible virus less than 1.2 predicts a preventable pandemic.
[h=4]Conclusions:[/h] Population immunity to H2 viruses is insufficient to block epidemic spread of H2 virus. An H2N2 pandemic would have lower impact in those born before 1968.
PMID: 29762672 DOI: 10.1093/infdis/jiy291
[h=1]Population Serologic Immunity to human and avian H2N2 viruses in the United States and Hong Kong for Pandemic Risk Assessment.[/h] Babu TM[SUP]1[/SUP], Perera R[SUP]2[/SUP], Wu JT[SUP]2[/SUP], Fitzgerald T[SUP]1[/SUP], Nolan C[SUP]1[/SUP], Cowling BJ[SUP]2[/SUP], Krauss S[SUP]3[/SUP], Treanor JT[SUP]1[/SUP], Peiris M[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]Introduction:[/h] Influenza A pandemics cause significant mortality and morbidity. H2N2 viruses have caused prior pandemic, and are circulating in avian reservoirs. The age-related frequency of current population immunity to H2 viruses was evaluated.
[h=4]Methods:[/h] Hemagglutinin inhibition (HAI) assays against historical human and recent avian influenza A (H2N2) viruses were performed across age groups in Rochester, NY and Hong Kong, China. The impact of existing cross-reactive HAI immunity on the effective reproductive number(R) was modeled.
[h=4]Results:[/h] 150 individual sera from Rochester and 295 from Hong Kong were included. 85% born in Rochester and Hong Kong before 1968 had HAI titers >1:40 against A/Singapore/1/57, and over 50% had titers >1:40 against A/Berkeley/1/68. The frequency of titers ≥1:40 to avian H2N2 A/Mallard/England/727/06 and A/Mallard/Netherlands/14/07 in subjects born before 1957 was 62% and 24%. There were no H2 HAI titers >1:40 in individuals born after 1968. These levels of seroprevalence reduce the initial R of A/Singapore/1/1957 or A/Berkeley/1/68 by 15%-20%. A basic reproductive number (R0) of the emerging transmissible virus less than 1.2 predicts a preventable pandemic.
[h=4]Conclusions:[/h] Population immunity to H2 viruses is insufficient to block epidemic spread of H2 virus. An H2N2 pandemic would have lower impact in those born before 1968.
PMID: 29762672 DOI: 10.1093/infdis/jiy291