The resurgence risk of COVID-19 in China in the presence of immunity waning and ADE: A mathematical modelling study. Issue 49 (22nd November 2022)

• Record Type: Journal Article
• Authors: Zhou, Weike; Tang, Biao; Bai, Yao; Shao, Yiming; Xiao, Yanni; Tang, Sanyi
• Is Part Of: Vaccine. Volume 40:Issue 49(2022)
• Page Start: 7141
• Page End: 7150
• Publication Date: 2022-11-22
• Subjects: COVID-19 -- Vaccination -- Immunity waning -- Antibody-dependent enhancement -- Resurgence risk -- Mathematical model; ADE Antibody-dependent enhancement -- PRCC Partial rank correlation coefficient; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2022.10.043
• Languages: English
• ISSNs: 0264-410X

Abstract

Abstract: The mass vaccination program has been actively promoted since the end of 2020. However, waning immunity, antibody-dependent enhancement (ADE), and increased transmissibility of variants make the herd immunity untenable and the implementation of dynamic zero-COVID policy challenging in China. To explore how long the vaccination program can prevent China at low resurgence risk, and how these factors affect the long-term trajectory of the COVID-19 epidemics, we developed a dynamic transmission model of COVID-19 incorporating vaccination and waning immunity, calibrated using the data of accumulative vaccine doses administered and the COVID-19 epidemic in 2020 in mainland China. The prediction suggests that the vaccination coverage with at least one dose reach 95.87%, and two doses reach 77.92% on 31 August 2021. However, despite the mass vaccination, randomly introducing infected cases in the post-vaccination period causes large outbreaks quickly with waning immunity, particularly for SARS-CoV-2 variants with higher transmissibility. The results showed that with the current vaccination program and 50% of the population wearing masks, mainland China can be protected at low resurgence risk until 8 January 2023. However, ADE and higher transmissibility for variants would significantly shorten the low-risk period by over 1 year. Furthermore, intermittent outbreaks can occur while the peak values of the subsequent outbreaks decrease, indicating that subsequent outbreaks boosted immunity in the population level, further indicating that follow-up vaccination programs can help mitigate or avoid the possible outbreaks. The findings revealed that the integrated effects of multiple factors: waning immunity, ADE, relaxed interventions, and higher variant transmissibility, make controlling COVID-19 challenging. We should prepare for a long struggle with COVID-19, and not entirely rely on the COVID-19 vaccine.