Experiments in animals show that boosters customized for the fast-spreading COVID variant offer little advantage over standard jabs.
of either the same shot or a version that incorporated Omicron’s heavily mutated spike protein, which the virus uses to enter human cells. The authors found that monkeys boosted with either vaccine mounted a broad antibody response against all variants of concern, including Omicron., which are responsible for cranking out antibodies to fend off a virus.
“For now, that’s a very good thing,” says Robert Seder, a co-author of the paper and an immunologist at the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. “It means we’re still able to cover all known variants with a boost” of the current vaccines. However, he cautions that the study only examined immune responses up to four weeks after the boost, and says that it is not clear how long the increase in antibody production will last.
A study of eight animals isn’t definitive. But given the condensed pandemic-style timescale, the study has value, says Montefiori.in mice found that giving an Omicron-matched booster after two doses of mRNA-based vaccine offered no more benefit than a standard booster. The study also looked at the Omicron-specific vaccine in ‘naive’ mice — those that had not previously been immunized — and found that the rodents produced high levels of potent antibodies against Omicron.