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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evaluation of COVID-19 vaccination strategies with a delayed second dose

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Author(s):
Moghadas, Seyed M. [1] ; Vilches, Thomas N. [2] ; Zhang, Kevin [3] ; Nourbakhsh, Shokoofeh [1] ; Sah, Pratha [4] ; Fitzpatrick, Meagan C. [4, 5] ; Galvani, Alison P. [4]
Total Authors: 7
Affiliation:
[1] York Univ, Agent Based Modelling Lab, Toronto, ON - Canada
[2] Univ Estadual Campinas, Inst Math Stat & Sci Comp, Campinas, SP - Brazil
[3] Univ Toronto, Fac Med, Toronto, ON - Canada
[4] Yale Sch Publ Hlth, Ctr Infect Dis Modeling & Anal, New Haven, CT - USA
[5] Univ Maryland, Sch Med, Ctr Vaccine Dev & Global Hlth, Baltimore, MD 21201 - USA
Total Affiliations: 5
Document type: Journal article
Source: PLOS BIOLOGY; v. 19, n. 4 APR 2021.
Web of Science Citations: 0
Abstract

Two of the Coronavirus Disease 2019 (COVID-19) vaccines currently approved in the United States require 2 doses, administered 3 to 4 weeks apart. Constraints in vaccine supply and distribution capacity, together with a deadly wave of COVID-19 from November 2020 to January 2021 and the emergence of highly contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants, sparked a policy debate on whether to vaccinate more individuals with the first dose of available vaccines and delay the second dose or to continue with the recommended 2-dose series as tested in clinical trials. We developed an agent-based model of COVID-19 transmission to compare the impact of these 2 vaccination strategies, while varying the temporal waning of vaccine efficacy following the first dose and the level of preexisting immunity in the population. Our results show that for Moderna vaccines, a delay of at least 9 weeks could maximize vaccination program effectiveness and avert at least an additional 17.3 (95% credible interval {[}CrI]: 7.8-29.7) infections, 0.69 (95% CrI: 0.52-0.97) hospitalizations, and 0.34 (95% CrI: 0.25-0.44) deaths per 10,000 population compared to the recommended 4-week interval between the 2 doses. Pfizer-BioNTech vaccines also averted an additional 0.60 (95% CrI: 0.37-0.89) hospitalizations and 0.32 (95% CrI: 0.23-0.45) deaths per 10,000 population in a 9-week delayed second dose (DSD) strategy compared to the 3-week recommended schedule between doses. However, there was no clear advantage of delaying the second dose with Pfizer-BioNTech vaccines in reducing infections, unless the efficacy of the first dose did not wane over time. Our findings underscore the importance of quantifying the characteristics and durability of vaccine-induced protection after the first dose in order to determine the optimal time interval between the 2 doses. (AU)

FAPESP's process: 18/24811-1 - Mathematical modelling for the transmission of schistosomiasis in low-prevalence areas
Grantee:Thomas Nogueira Vilches
Support type: Scholarships in Brazil - Post-Doctorate