WHO calls for moratorium on the use of COVID-19 vaccine booster doses

20/09/2021

An international group of scientists, including staff from the World Health Organization (WHO), in a recent issue of the journal The Lancet, questioned the need for boosters to increase the immune response provided by COVID-19 vaccines. Their main point was that, to date, fully vaccinated people have been shown to remain highly protected against severe COVID-19 disease. Further, they recommend that the extra doses be used to vaccinate people who have not yet been vaccinated. 

Even if it were shown that booster doses could potentially decrease the risk of severe disease, the amount of vaccine available at the moment would save more lives if used to vaccinate the unvaccinated population than if it were used as a booster for people already vaccinated. The authors also indicated that the booster might be advisable for people with immunodeficiencies or immunosuppression who had already received the full schedule of one or two doses of vaccine. 

The evidence presented so far seems to show that efficacy against severe disease is maintained, and that humoral immunity appears to be waning, but the relation between neutralizing antibody titers and vaccine efficacy has not yet been established. The cell-mediated response, which is longer-lasting, also plays a role in protection.


The findings being presented to justify booster doses are from observational studies that, for various reasons, may be biased by patient characteristics, registry systems, differences between vaccinated and unvaccinated groups, social patterns of behavior, etc.

The authors also expressed concern about the impact that messages on boosters could have on the population, along with concern about the potential for adverse events resulting from a booster dose. 

Most important, however, is the benefit that could be achieved globally if the vaccine were administered to a greater number of unvaccinated people, thereby hastening the end of the pandemic by reducing the chance for new variants to emerge. 

WHO is calling for a moratorium on the use of booster doses until more people worldwide have received primary vaccination. 

Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)02046-8/fulltext

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