A new study conducted in monkeys suggests that there may not be any extra benefit from updating COVID-19 vaccines to target the Omicron variant.
The study involved monkeys vaccinated with two doses of Moderna’s vaccine who were dosed nine months later with either the conventional Moderna booster or one specifically targeting the Omicron variant.
The work, by scientists at the National Institutes of Allergy and Infectious Diseases’s Vaccine Research Center, shows that animals boosted with the original vaccine had similar levels of protection against disease in the lungs as did primates that received an updated booster based on the Omicron strain.
The researchers tested various aspects of the animals’ immune responses and exposed them to the virus. The scientists found both boosters produced “comparable and significant increases in neutralizing antibody responses” against all of the variants of concern, including Omicron, according to the study.
Both Moderna and BioNTech-Pfizer have started testing Omicron-specific boosters of their vaccines in human clinical trials.
“This is very, very good news. It means we don’t need to radically redesign the vaccine to make it an Omicron vaccine,” Mr. Daniel Douek, a vaccine researcher at the National Institute of Allergy and Infectious Diseases who co-led the study, said.
Mr. Douek said that he believes the reason is that both the original and the Omicron-specific vaccines are “cross-reactive,” meaning they can recognize lots of different variants.
The results are similar to studies testing a Moderna booster targeting the Beta variant, said Dr. John Moore, a professor of microbiology and immunology at Weill Cornell Medical College who was not involved in the study.
“Let’s see what the human data show. Monkey data are generally pretty predictive, but you are going to need the human data,” Dr. Moore said.
One 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, something that could not be done in human trials, Dr. Moore said.