The FDA has approved a second Covid vaccine booster for anyone age 50 or older, as well as anyone 12 and older with a health condition that significantly weakens their immune system. The Calvert County Health Department has begun to offer second boosters to qualifying individuals. Boosters are also available through many local medical offices and pharmacies.
The evidence supporting the benefits of a first booster were overwhelmingly clear. The medical evidence for a second booster is more limited at this time. The U.S., Israel, U.K., and Germany have all approved second boosters, but eligibility criteria differ in each country. We recommend that those considering a second booster discuss the decision with their personal healthcare provider.
The primary benefits of boosters are raising the antibody levels that actively circulate in the
bloodstream and enhancing memory cells in the immune system. Four to five months after
completion of the initial vaccine series, circulating antibodies begin to decline. But if a person is later exposed to Covid, memory cells will quickly activate to produce more antibodies and
mobilize other immune defenses. These memory cells are enhanced after the first booster
vaccination.
Evidence clearly shows that after each Covid booster, high levels of antibody will circulate for 4-5 months. During periods of higher circulating antibodies, if a person is exposed to the virus, the immune response is almost immediate. Once the circulating antibodies decline, those who were fully vaccinated continue to have a faster and more robust response than those who are
unvaccinated, but there is a delay of several days to a week before their body generates a
complete response. For most people, this delay does not put them at risk of serious illness. But in people who are older or have significantly weakened immune systems, in some cases, this delayed response can result in serious illness or death.
Researchers are working on enhanced vaccines that will provide longer-lasting circulating
antibodies, but it is unclear when such vaccines will be available. Until then, people at higher
risk of serious illness from Covid should continue to take reasonable precautions to minimize
exposures, such as wearing face covering in public and avoiding crowded spaces. Although the amount of Covid transmission in Calvert is now much lower than we experienced in January, the virus continues to cause new infections. The BA.2 variant is now responsible for one-third of local infections. Whether it’s because of this more transmissible variant or because fewer people are taking precautions, we have seen a measurable increase in cases across the county over the past two weeks.
We encourage everyone to finish the initial 2-dose vaccine regimen and have an initial booster 4-5 months later. This remains the best way to protect yourself, your family, and others you care about. Regardless of your decision on a second booster at this time, please be mindful that Covid shows no signs of completely going away. If you develop symptoms that may be caused by Covid, please get tested. Your healthcare provider can now prescribe medication that is 85% effective in treating breakthrough cases if the infection is caught within the first 5 days of illness.
