Determining Existing Human Population Immunity as Part of Assessing Influenza Pandemic Risk.
Emerg Infect Dis
; 28(5): 977-985, 2022 05.
Article
em En
| MEDLINE
| ID: mdl-35447069
ABSTRACT
Zoonotic influenza infections continue to threaten human health. Ongoing surveillance and risk assessment of animal viruses are needed for pandemic preparedness, and population immunity is an important component of risk assessment. We determined age-stratified hemagglutinin inhibition seroprevalence against 5 swine influenza viruses circulating in Hong Kong and Guangzhou in China. Using hemagglutinin inhibition seroprevalence and titers, we modeled the effect of population immunity on the basic reproduction number (R0) if each virus were to become transmissible among humans. Among 353 individual serum samples, we reported low seroprevalence for triple-reassortant H1N2 and Eurasian avian-like H1N1 influenza viruses, which would reduce R0 by only 18%-20%. The smallest R0 needed to cause a pandemic was 1.22-1.24, meaning existing population immunity would be insufficient to block the spread of these H1N1 or H1N2 variants. For human-origin H3N2, existing population immunity could suppress R0 by 47%, thus reducing pandemic risk.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vírus da Influenza A
/
Doenças dos Suínos
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Infecções por Orthomyxoviridae
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Influenza Humana
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Vírus da Influenza A Subtipo H1N1
Tipo de estudo:
Etiology_studies
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Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article