It is expected that the Food and Drug Administration would approve new COVID-19 booster shots without the results from a trial demonstrating whether the shots were secure and effective in humans, which is a crucial component of its typical decision-making process.

When the FDA makes its judgments, testing of the modified shots, which target the most recent iterations of the Omicron strain, will not be complete.

As reported by the Wall Street Journal (WSJ), the agency intends to evaluate the doses instead using information from other sources, such as mouse research, the characteristics of the original vaccines, and the effectiveness of earlier generations of boosters that were designed to target older kinds of Omicron.

“Real world evidence from the current mRNA COVID-19 vaccines, which have been administered to millions of individuals, show us that the vaccines are safe,” FDA Commissioner Robert Califf said in a recent tweet.

The FDA’s approach to flu shots, which are modified yearly to keep up with evolving flu viruses, is comparable to the clearance of the doses without data from clinical studies, which involve testing on humans.

However, several vaccination specialists have expressed concerns about the strategy and have advised the FDA to wait.

As per medical experts, the comparison with flu vaccines isn’t sound because flu viruses mutate so rapidly that shots from one year don’t offer protection for the next, while currently available COVID-19 shots continue to keep people out of the hospital.

A nurses fills up syringes for patients as they receive their coronavirus disease (COVID-19) booster vaccination during a Pfizer-BioNTech vaccination clinic in Southfield, Michigan, US. Photo credits: Reuters

In addition to evaluating the boosters without clinical-trial data, the FDA won’t convene another element from its earlier COVID-19 vaccine reviews: a meeting of advisers who make recommendations whether the agency should authorize a shot.

Despite the virus they were intended to combat evolving, the COVID-19 vaccinations that are currently available in the United States, which were initially authorized for use in December 2020, have not been changed.

Researchers discovered that while the shots were still effective against more established strains, they were less so against more recent Omicron subvariants like BA.5.

Federal health officials ordered Pfizer Inc. and its partner BioNTech SE, as well as Moderna Inc., to upgrade their vaccines in late June in order to target BA.5, the original strain of the virus, the Omicron subvariant known as BA.4, and this subvariant’s variant.

The Pfizer-BioNTech vaccine is anticipated to begin human trials this month, while Moderna’s vaccine targeting the subvariants has already begun. However, the results won’t be ready prior to the US government’s anticipated fall booster campaign.

According to John Grabenstein, director of scientific communications for Immunize.org, a nonprofit that seeks to increase immunization rates, the retooled shots are similar to the original shots but tailored to combat the most recent variants, like keys that are nearly identical but have slightly different ridges and valleys, as reported by the WSJ.