UC San Diego is part of national clinical trial on COVID-19 variant vaccines

A vial of the COVID-19 vaccine made by Pfizer and BioNTech.

Fully vaccinated and boosted San Diego County residents are among those nationwide who will be able to participate in a new clinical trial that seeks to test combinations of COVID-19 vaccines that target variants, including Beta, Delta and Omicron.

UC San Diego in La Jolla is among 24 sites selected to enroll residents in the COVID-19 Variant Immunologic Landscape Trial, or COVAIL, a major nationwide effort funded by the National Institute of Allergy and Infectious Diseases.

The investigation initially plans to enroll about 600 participants in six different randomly selected groups, each of which will receive a different combination of vaccines developed by pharmaceutical giant Moderna.

To date, the only vaccines approved for general use are those focused on the initial strain that emerged in Wuhan, China, in 2019. As the virus has mutated, causing additional waves of infection, companies have worked to update their initial offerings, retargeting the same mRNA technology on new features appearing in the coronavirus’s latest versions.

The idea that drives the trial is to map the immune system responses to different variants, populating computer models with enough information to make the best predictions about which combinations would produce the strongest protection against the coronavirus’s next successful mutation, according to Dr. Susan Little, a professor of medicine at UCSD and principal investigator of the local trial site.

“When a new variant comes along, whatever it is, we want to have an immune response that matches as closely as possible,” Little said.

Initially set for 600 participants, the research effort will expand to 1,500 as additional variant vaccines are ready for testing.

Participants must be at least 18 and fully vaccinated, with evidence that they also have received a booster shot. According to the county health department’s latest update, about 1.2 million residents across the region have received their boosters, making them eligible to participate if they are in good health.

Enrollment will be targeted toward specific age groups, with the study skewing toward the older age groups that are at significantly greater risk of severe consequences if they get infected. About 45 percent of COVAIL participants will be 65 or older.

Investigators also want to better understand how a previous coronavirus infection affects the immune response elicited by vaccines, so 35 percent will have confirmed previous infections.

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