As vaccine rollout proceeds in San Francisco and several vaccines have completed Phase 3 trials, the Covid-19 pandemic is throwing what UCSF Grand Rounds moderator Dr. Bob Wachter called the “curve ball of variance” with the first two cases of the B131 “South African” variant confirmed in the Bay Area. But it did not take long for Dr. Monica Gandhi, his first guest who looked at data from the vaccine trials, to dispel fears of the variants. Other guests addressed  strategies to address vaccine hesitancy and insider perspectives from President Joe Biden’s COVID-19 Task Force, Wachter pulled together a team of seasoned experts. 

Vaccine Trials

There are currently six covid vaccine trials with Phase 3 data. Two, the Moderna and Pfizer vaccines, are approved in the United States and one more, the Johnson & Johnson vaccine, will be considered for Emergency Use Authorization by the Food and Drug Administration on February 26th. These vaccines, along with AstraZeneca, NovaVax, and Sputnik V, all work by introducing a harmless spike protein unique to covid to cells. Once introduced, the body recognizes the foreign protein and begins to produce antibodies to fight the infectious agent. 

Vaccines are important in eliciting antibody responses such as B cells and plasma, but they also “elicit a robust T cell response,” said Dr. Monica Gandhi, associate chief of ZSFG’s Division of HIV, Infectious Diseases, and Global Medicine and director of the UCSF-Gladstone Center for AIDS Research. 

This T cell response is important because “there is lots and lots of data that essentially T cell responses modulate severity of disease. In fact, strong T cell responses were documented in all six of these trials. It likely led to this prevention of severe disease,” Gandhi said. If an individual gets reinfected (after natural infection or the vaccine), the disease should be mild as long as the body mounts a strong T cell response, she said. 

Gandhi also conducted an overview of each of the vaccine’s non-clinical results, how protective the vaccine was against hospitalization and severe disease, and efficacy in mild disease, which can be viewed in detail below. 



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