University of Washington study sparks conversation about updated COVID-19 vaccine effectiveness

A popular social media post referenced a University of Washington preprint study, which found that people who received three doses of the original COVID-19 vaccine developed strong immunity against COVID-19. The study also found that people who received the most recently updated COVID-19 vaccine, which targets the Omicron subvariant XBB.1.5, produced few to no antibodies specific to that subvariant. Responses to the social media post referenced “immune imprinting,” a phenomenon in which the immune system relies on the memory of its initial exposure to a virus when it responds to a slightly different version of the virus. Some social media users claimed that this study proves that updated COVID-19 vaccines do not provide any protection against COVID-19.

Recommendation: These types of posts undermine the effectiveness of COVID-19 vaccines and may promote distrust in public health guidance. Talking points may emphasize that the study referenced in the initial post is a preprint and has not yet been peer-reviewed. The study’s author stated that “mRNA vaccines may have been so good and elicited such strong immune responses that the imprinting may be stronger than what we have been used to seeing with vaccines for other viruses such as for influenza virus.” Additional messaging may emphasize that staying up to date on COVID-19 vaccines prevents severe illness, hospitalization, death, and long COVID. The CDC recommends the updated COVID-19 vaccine for everyone 6 months and older.