Periodic vaccination for post-pandemic management: Insights from and planning beyond COVID-19

Abstract

Waning immunity to the SARS-CoV-2 virus and the inevitability of viral mutations necessitate a large-scale periodic revaccination program. Rapid mass vaccination may quickly suppress an epidemic, but it may have an unintended downstream effect of creating a surge in population susceptibility later when vaccinated people lose their immunity all at the same time. To test this hypothesis, we conducted a simulation study comparing pulse vaccination, the repeated administration of “booster” vaccines in large pulses occurring at fixed intervals, and constant vaccination, the continuous administration of booster vaccines at a slower, constant pace. We showed that constant vaccination can maintain population susceptibility and therefore incident deaths at a constant, manageable level; while pulse vaccination can induce large recurrent epidemics. The advantage of constant vaccination is only realized, however, in a post-pandemic scenario when a high level of population immunity has already been attained through a combination of vaccination and natural infection. At the beginning of a novel pandemic, aggressive vaccination is recommended to prioritize immediate protection over long-term protection. In a counterfactual analysis, we showed that prematurely switching to constant vaccination would have significantly increased the disease burden during the Delta variant wave in August 2021.

Keywords:

• COVID-19
• post-pandemic management
• periodic vaccination
• SEIR
• public health

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Science Foundation awards 2035360 and 2035361, and the Rockefeller Foundation COVID-19 Modeling Accelerator.