Lack of neutralizing antibodies against influenza A viruses in adults during the 2022/2023 winter season - a serological study using retrospective samples collected in Hong Kong.
Int J Infect Dis
; 135: 1-4, 2023 Oct.
Article
en En
| MEDLINE
| ID: mdl-37481108
ABSTRACT
OBJECTIVES:
Since the onset of the COVID-19 pandemic in 2020, there has been a significant decline in seasonal influenza infection cases in Hong Kong. However, this decline has also resulted in reduced opportunities for the development of influenza-specific antibodies in the community. The levels of antibodies required for protection against recently circulating influenza A viruses in the post-COVID-19 era remain unclear.METHODS:
This study involved the analysis of paired plasma samples collected from 479 healthy adults in Hong Kong in 2021 and 2022. The neutralizing titers of plasma against influenza A (H1N1) and (H3N2) viruses circulating before and after the COVID-19 outbreak were determined using a microneutralization assay.RESULTS:
The H1N1 and H3N2 vaccine strains selected for the 2022/23 season were found to be closely related to the recently circulating viruses. However, in the samples collected in 2022, only 14.61% and 0.42% showed a neutralization titer (MN50) ≥120 against H1N1 A/Wisconsin/588/2019 (H1/Wis19) and H3N2 A/Darwin/6/2021 (H3/Dar21), respectively. Notably, participants who reported receiving annual flu vaccinations exhibited a higher seropositive rate for H1/Wis19 compared to those who had never received the flu vaccine (28.06% vs. 5.30%).CONCLUSION:
Our results indicate that adults in Hong Kong generally lack neutralizing antibodies against circulating influenza A viruses, particularly H3N2. These findings underscore the importance of promoting flu vaccination in the post-COVID-19 era.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Virus de la Influenza A
/
Vacunas contra la Influenza
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Gripe Humana
/
Subtipo H1N1 del Virus de la Influenza A
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COVID-19
Tipo de estudio:
Observational_studies
/
Risk_factors_studies
Límite:
Adult
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Humans
País como asunto:
Asia
Idioma:
En
Año:
2023
Tipo del documento:
Article