Return to normal pre-COVID-19 life is delayed by inequitable vaccine allocation and SARS-CoV-2 variants.

Feng Liu,Xiaowei Nie,Xin Li,Adan Wu,Chunfeng Ma,Zebin Zhao

doi:10.1017/s0950268822000139

Abstract

As a result of the COVID-19 pandemic, whether and when the world can reach herd immunity and return to normal life and a strategy for accelerating vaccination programmes constitute major concerns. We employed Metropolis-Hastings sampling and an epidemic model to design experiments based on the current vaccinations administered and a more equitable vaccine allocation scenario. The results show that most high-income countries can reach herd immunity in less than 1 year, whereas low-income countries should reach this state after more than 3 years. With a more equitable vaccine allocation strategy, global herd immunity can be reached in 2021. However, the spread of SARS-CoV-2 variants means that an additional 83 days will be needed to reach global herd immunity and that the number of cumulative cases will increase by 113.37% in 2021. With the more equitable vaccine allocation scenario, the number of cumulative cases will increase by only 5.70% without additional vaccine doses. As SARS-CoV-2 variants arise, herd immunity could be delayed to the point that a return to normal life is theoretically impossible in 2021. Nevertheless, a more equitable global vaccine allocation strategy, such as providing rapid vaccine assistance to low-income countries/regions, can improve the prevention of COVID-19 infection even though the virus could mutate.

Highlights

Due to the persistence of the global outbreak of coronavirus disease 2019 (COVID-19), addressing the trade-off between containing the pandemic and returning to normal pre-COVID19 life has become increasingly urgent [1, 2]
We first investigate the perspective of the global COVID-19 pandemic caused only by SARSCoV-2, which means that the vaccine effectiveness against the virus after full vaccination is approximately 90%
According to the current vaccinations administered, the results show that only 61 countries will have reached herd immunity by the end of 2021 (Fig. 3A)

Summary

Introduction

Due to the persistence of the global outbreak of coronavirus disease 2019 (COVID-19), addressing the trade-off between containing the pandemic and returning to normal pre-COVID19 life has become increasingly urgent [1, 2]. One solution to this dilemma is international cooperation with respect to vaccination [3]. By 12 September 2021, 76% of the 50 richest countries had administered more than 100 vaccine doses per 100 people, whereas 66% of the 50 poorest countries had not yet administered 10 doses per 100 people This inequitable allocation of vaccines appears to be worsening because some countries with high vaccination rates have decided to offer COVID-19 booster vaccinations in the few months [26]

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Results

Discussion

Conclusion