US government researchers have said they pitted the current Moderna COVID-19 booster shot against an omicron-specific booster in a study in monkeys. The results showed no significant differences, suggesting a new booster for the new variant may not be required.
The study, which is yet to be peer reviewed, involved monkeys vaccinated with two doses of Moderna's vaccine. They were dosed nine months later with either the conventional booster or one specifically targeting the omicron variant.
Researchers said they found both boosters produced "comparable and significant increases in neutralizing antibody responses" against all variants.
"This is very, very good news," Daniel Douek, a vaccine researcher at the National Institute of Allergy and Infectious Diseases who co-lead the study, was quoted as saying by Reuters news agency. "It means we don't need to radically redesign the vaccine to make it an omicron vaccine."
John Moore, a professor of microbiology and immunology who was not involved in the study, said a key advantage of the monkey study is that researchers can boost the animals and then infect them with the virus and measure the immune response.
"Let's see what the human data show," Moore said. "Monkey data are generally pretty predictive, but you are going to need the human data."
Moderna and Pfizer have started testing omicron-specific boosters of their vaccines in humans.