tetano
Editor, Senior Moderator
Am J Prev Med
. 2022 Apr;62(4):503-510.
doi: 10.1016/j.amepre.2021.11.007. Epub 2022 Feb 24.
Impact of Low Rates of Influenza on Next-Season Influenza Infections
Mary G Krauland[SUP] 1 [/SUP], David D Galloway[SUP] 2 [/SUP], Jonathan M Raviotta[SUP] 3 [/SUP], Richard K Zimmerman[SUP] 3 [/SUP], Mark S Roberts[SUP] 4 [/SUP]
Affiliations
Abstract
Introduction: Interventions to curb the spread of COVID-19 during the 2020-2021 influenza season essentially eliminated influenza during that season. Given waning antibody titers over time, future residual population immunity against influenza will be reduced. The implication for the subsequent 2021-2022 influenza season is unknown.
Methods: An agent-based model of influenza implemented in the Framework for Reconstructing Epidemiological Dynamics simulation platform was used to estimate cases and hospitalizations over 2 successive influenza seasons. The impact of reduced residual immunity owing to protective measures in the first season was estimated over varying levels of similarity (cross-immunity) between influenza strains over the seasons.
Results: When cross-immunity between first- and second-season strains was low, a decreased first season had limited impact on second-season cases. High levels of cross-immunity resulted in a greater impact on the second season. This impact was modified by the transmissibility of strains in the 2 seasons. The model estimated a possible increase of 13.52%-46.95% in cases relative to that in a normal season when strains have the same transmissibility and 40%-50% cross-immunity in a season after a very low one.
Conclusions: Given the light 2020-2021 influenza season, cases may increase by as much as 50% in 2021-2022, although the increase could be much less, depending on cross-immunity from past infection and transmissibility of strains. Enhanced vaccine coverage or continued interventions to reduce transmission could reduce this high season. Young children may have a higher risk in 2021-2022 owing to limited exposure to infection in the previous year.
. 2022 Apr;62(4):503-510.
doi: 10.1016/j.amepre.2021.11.007. Epub 2022 Feb 24.
Impact of Low Rates of Influenza on Next-Season Influenza Infections
Mary G Krauland[SUP] 1 [/SUP], David D Galloway[SUP] 2 [/SUP], Jonathan M Raviotta[SUP] 3 [/SUP], Richard K Zimmerman[SUP] 3 [/SUP], Mark S Roberts[SUP] 4 [/SUP]
Affiliations
- PMID: 35305778
- DOI: 10.1016/j.amepre.2021.11.007
Abstract
Introduction: Interventions to curb the spread of COVID-19 during the 2020-2021 influenza season essentially eliminated influenza during that season. Given waning antibody titers over time, future residual population immunity against influenza will be reduced. The implication for the subsequent 2021-2022 influenza season is unknown.
Methods: An agent-based model of influenza implemented in the Framework for Reconstructing Epidemiological Dynamics simulation platform was used to estimate cases and hospitalizations over 2 successive influenza seasons. The impact of reduced residual immunity owing to protective measures in the first season was estimated over varying levels of similarity (cross-immunity) between influenza strains over the seasons.
Results: When cross-immunity between first- and second-season strains was low, a decreased first season had limited impact on second-season cases. High levels of cross-immunity resulted in a greater impact on the second season. This impact was modified by the transmissibility of strains in the 2 seasons. The model estimated a possible increase of 13.52%-46.95% in cases relative to that in a normal season when strains have the same transmissibility and 40%-50% cross-immunity in a season after a very low one.
Conclusions: Given the light 2020-2021 influenza season, cases may increase by as much as 50% in 2021-2022, although the increase could be much less, depending on cross-immunity from past infection and transmissibility of strains. Enhanced vaccine coverage or continued interventions to reduce transmission could reduce this high season. Young children may have a higher risk in 2021-2022 owing to limited exposure to infection in the previous year.