Current vaccine booster just as effective as Omicron-specific ones, US study finds

A study has found that an Omicron-specific booster may not be any more effective than existing COVID-19 vaccine boosters. 

The study, conducted by the National Institute of Allergy and Infectious Diseases Vaccine Research Centre (NIAID) in the United States, administered either the Moderna vaccine or an Omicron-specific version to primates that had already been vaccinated twice with the Moderna vaccine nine months prior. 

It found that both groups of primates had the same level of immune response, and both boosters controlled viral replication equally. 

“Therefore, an Omicron boost may not provide greater immunity or protection compared to a boost with the current [Moderna] vaccine,” the researchers said.

Pfizer and Moderna announced in late January that they had started clinical trials for an Omicron-specific booster. 

The Omicron variant is now the dominant COVID-19 strain in Singapore and many other countries, with higher transmissibility but lower severity.

Although NIAID’s study has not been peer reviewed yet, its findings bring good news. 

“It means we don’t need to radically redesign the vaccine to make it an Omicron vaccine,” Dr Daniel Douek, a researcher who co-led the study, told Reuters.