Will the large‐scale vaccination succeed in containing the COVID‐19 pandemic and how soon?

Abstract

BackgroundThe availability of vaccines provides a promising solution to contain the COVID‐19 pandemic. However, it remains unclear whether the large‐scale vaccination can succeed in containing the COVID‐19 pandemic and how soon. We developed an epidemiological model named SUVQC (Suceptible‐Unquarantined‐Vaccined‐Quarantined‐Confirmed) to quantitatively analyze and predict the epidemic dynamics of COVID‐19 under vaccination.MethodsIn addition to the impact of non‐pharmaceutical interventions (NPIs), our model explicitly parameterizes key factors related to vaccination, including the duration of immunity, vaccine efficacy, and daily vaccination rate etc. The model was applied to the daily reported numbers of confirmed cases of Israel and the USA to explore and predict trends under vaccination based on their current epidemic statuses and intervention measures. We further provided a formula for designing a practical vaccination strategy, which simultaneously considers the effects of the basic reproductive number of COVID‐19, intensity of NPIs, duration of immunological memory after vaccination, vaccine efficacy and daily vaccination rate.ResultsIn Israel, 53.83% of the population is fully vaccinated, and under the current NPI intensity and vaccination scheme, the pandemic is predicted to end between May 14, 2021, and May 16, 2021, assuming immunity persists for 180 days to 365 days. If NPIs are not implemented after March 24, 2021, the pandemic will end later, between July 4, 2021, and August 26, 2021. For the USA, if we assume the current vaccination rate (0.268% per day) and intensity of NPIs, the pandemic will end between January 20, 2022, and October 19, 2024, assuming immunity persists for 180 days to 365 days. However, assuming immunity persists for 180 days and no NPIs are implemented, the pandemic will not end and instead reach an equilibrium state, with a proportion of the population remaining actively infected.ConclusionsOverall, the daily vaccination rate should be decided according to vaccine efficacy and immunity duration to achieve herd immunity. In some situations, vaccination alone cannot stop the pandemic, and NPIs are necessary to supplement vaccination and accelerate the end of the pandemic. Considering that vaccine efficacy and duration of immunity may be reduced for new mutant strains, it is necessary to remain cautiously optimistic about the prospect of ending the pandemic under vaccination.