The U.S. Department of Health and Human Services (HHS) announced its plan last month to begin offering the COVID-19 vaccine booster shot this fall, but Dr. Monica Ghandi, who teaches medicine at the University of California in San Francisco (UCSF) and is director at the UCSF Gladstone Center for AIDS Research, doesn’t plan on getting the third shot.
“Only if my hospital makes me,” Dr. Ghandi said. “There is going to be criteria that comes out. I'm positive the FDA is going to be reasonable about this. One criteria could be healthcare workers because even getting a mild infection, I can't afford to stay out of work, and I can't also spread it all over to people. So, that group has been floated in these conversations the last couple of days as the conversation has shifted back to doing a targeted approach for boosters of health care workers.”
The Delta strain of the coronavirus virus, which is more transmissible, has become the dominant variant in recent months, according to Medical News Today.
“Delta is so transmissible that it’s the most evolutionarily sound thing the virus can do for itself,” Ghandi said. “We don't like it but that's exactly what it's doing. It's making itself more transmissible but we can get on top of Delta through immunity.”
The booster provides protection against COVID-19 and its many variants due to T-cells, Ghandi said.
“As an HIV doctor, I know how important T cells are,” she said. “They provide long-term immune defenses against severe disease from viruses. Because T-cells protect us against severe disease, you may get lifelong protection against severe illness.”
Currently, the CDC is recommending that moderately to severely immunocompromised people receive the additional dose but that could broaden since President Biden announced this week that the Department of Labor will be writing a rule requiring companies with more than 100 employees to mandate vaccinations or once-per-week testing for their workers.
“All the trials, including Moderna, Pfizer, and Johnson & Johnson, didn't just measure antibodies,” Ghandi said. “They took the trouble to measure T-cell response and they documented strong T-cell responses from the vaccines and almost a hundred percent protection from severe disease. That's how amazing T-cell response from these vaccines is.”
Ghandi further stated that vaccine effectiveness depends on various factors including age, previous infection, underlying health conditions, close proximity of people living together, high levels of vaccine uptake, number of doses, and timing between doses.
"Vaccine effectiveness depends on whether you consider waning effectiveness to be a minor infection versus the protection against severe disease," she said. "Vaccine effectiveness is not just about one thing. Longer time between doses usually increases your immunogenicity. It can also be about how much of the virus you are exposed to."