SARS-CoV-2 vaccination strategies: Should the extended dosing interval strategy be implemented in future pandemics?

Abstract

The World Health Organization (WHO) considered COVID-19 for more than three years a public health emergency of international concern (PHEIC) at a pandemic level. After a cumulate of 770,875,433 confirmed cases, including 6,959,316 deaths (up to September 19, 2023), fortunately, the COVID-19 mortality burden has significantly decreased in the last year (2022–2023) primarily due to effective vaccination (a total of 13,505,262,477 doses have been administered globally) (https://covid19.who.int/), despite Omicron and its sublineage variants' emergence [1,2]. However, the vaccine allocation was not as smooth as everyone would have liked, considering shortages or difficulties in promptly obtaining the vaccines for several countries, especially low- and middle-income countries (LMIC).