Advanced search
Start date
(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

Full text
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
[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

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