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.
Senior author Robert Seder said the findings are similar to those of a study the group conducted last year, when researchers compared a booster shot based on the Beta variant to the existing vaccine.
Seder said studies will need to be done in people to ensure the findings hold, but at this point it doesn’t appear that the vaccine strain needs to be updated.
“We believe protection against variants of concern will be important, especially as we look ahead to the fall of 2022,” the company said.
“Accordingly, changing to an Omicron boost may well be unnecessary — literally more trouble than it’s worth,” Moore said in an email.
Angela Rasmussen, a coronavirus virologist at the University of Saskatchewan’s Vaccine and Infectious Disease Organization, concurred, though she cautioned that these findings are based on a small number of animals.
“The existing boosters provide improved protection against infection,” she said in an email.
The paper notes that data have begun to emerge that suggest that an Omicron-based vaccine would not be ideal if given on its own, because Omicron may not generate the same level of cross-protection as the original vaccine strain does.