FDA Outlines Fast Path for Shots Against New Virus Variants

Drugmakers won’t have to perform massive trials for new vaccines or booster shots developed to combat worrisome new variants of the coronavirus, the U.S. Food and Drug Administration said.

In documents released by the agency Monday, it said immunizations that protect against the variants could receive clearance based on so-called immunogenicity studies, where researchers vaccinate people and then conduct laboratory tests to measure the strength of their immune response. These tests, similar to what is done for annual flu shots, are far simpler than the standard efficacy studies used for clearance of the initial vaccines, which involved thousands of volunteers and took months of work.

While coronavirus cases have been declining across the U.S. in recent weeks, health officials are concerned that fast-spreading variants could trigger higher infection rates even amid the mass vaccination campaign. The variants are already affecting the accuracy of some tests and potency of treatments for the infection, the agency said.

“By issuing these guidances, we want the American public to know that we are using every tool in our toolbox to fight this pandemic, including pivoting as the virus adapts,” said Janet Woodcock, acting FDA commissioner, in a statement.

The best way to combat the emergence of genetic mutations that are making the virus more transmissible and virulent is to protect people from becoming infected, public health officials said. Immunizations have been accelerating after a slow initial rollout, with 63.1 million doses administered as of Monday, according to Bloomberg’s Vaccine Tracker.

Modified Products

The agency is encouraging drugmakers to test their modified products in people who were previously immunized, which could come in the form of a booster shot, and in those who haven’t been vaccinated, making it their first shot. Manufacturers must prove that neutralizing antibody levels produced by a modified vaccine against new strains are at least as strong as those produced following vaccination against the initial strains.

Importantly, because these studies are based on lab test results in people, the guidance means that drug companies wouldn’t have to conduct lengthy trials that directly measure how much a new vaccine reduces cases of illness compared to a placebo shot. Further simplifying the process, the drugmakers could perform the trials in one age group only, such as adults ages 18 to 55, and extrapolate the findings to other age ranges for which a vaccine has been authorized, the FDA said.

Vaccine strains have been rapidly evolving, and variants common in South Africa and Brazil in particular have mutations that may reduce the effectiveness of existing vaccines. That has led companies including Moderna Inc. and Pfizer Inc. to start exploring plans for developed modified vaccines or booster shots.

The FDA has warned that genetic mutations could alter the accuracy of some available diagnostics, though it said the impact isn’t yet significant. It is considering a requirement that testmakers acknowledge their products may not detect all variants and note which ones were circulating when an individual test was studied.

The agency also said it’s aware that some monoclonal antibodies, the medicines developed to treat patients after they have been infected, aren’t as effective against the novel strains of the virus. Regulators laid out recommendations for drugmakers to most efficiently develop the next generation of the therapeutics, which mimic the immune system’s natural response to infection.

©2021 Bloomberg L.P.

BQ Install

Bloomberg Quint

Add BloombergQuint App to Home screen.