EMA affirms that administering several doses of anti-COVID vaccines in the short term is not sustainable

The European Medicines Agency (EMA)) and other international regulators reiterated that the administration of several doses of vaccines against the COVID-19 “at short intervals is not a sustainable approach” in the long term.

These organizations believe, however, that “the need is increasingly clear” to administer booster injections to extend the protection of COVID-19 vaccines.

These ideas are part of a report published this Friday on the conclusions of a meeting held last week of drug regulators from different regions, co-chaired by the EMA and the United States Food and Drug Administration (FDA).

In the document, the agencies urged to “develop a long-term strategy” on the types of vaccines needed to manage COVID-19 in the future.

“In discussing potential vaccination approaches against omicron and other variants of the virus, meeting participants agreed that giving multiple booster doses at short intervals is not a sustainable long-term approach,” they add.

Participants included experts from the World Health Organization (WHO), the European Commission, South Africa, and Israel, among other countries, who acknowledged that vaccines offer less protection against contagion and mild COVID-19, but are effective against hospitalization and severe illness with omicron, especially after the booster dose.

“It is becoming increasingly clear that a booster dose is needed to extend the protection of the vaccine,” they consider.

The debate on the long-term strategy is “an ongoing global debate”, acknowledges the EMA, which stresses that this discussion “is at the crossroads of science, public policy and public health” and will require coordination between the authorities public health at all levels.

Regarding the composition of the updated vaccines, drug regulators urge the international scientific community and pharmaceutical companies to “seek alternative approaches to monovalent vaccines”, exploring the feasibility of developing bivalent or multivalent vaccines that can neutralize other variants of interest in the future.

In any case, they emphasize that any vaccine with an adapted composition must undergo clinical studies to support its safety, quality and efficacy before being approved for use in mass vaccination campaigns.

“These studies should be designed to show that the immune response, measured as neutralizing antibodies, generated by the updated vaccine is superior to that achieved with current vaccines. The ability of the updated vaccines to cross-neutralize other variants of interest would be an additional feature.”

Marco Cavaleri, head of Vaccination Strategy, warned on Tuesday that if it is necessary to vaccinate again in the future, at least to risk groups, the reinforcement could be offered with the arrival of the cold, as is already done with the flu, because “this would increase the antibody response when we need it most”, as opposed to consecutive doses.

“The repeated administration of boosters with several short time intervals could reduce the level of antibodies that can be produced in each administration, since our immune system needs a certain amount of time to show the response to the antigen that is presented to it. This will potentially make vaccination a little less efficient over time.”