Your body’s immunity to many viruses, whether acquired naturally or through a vaccine, declines over time. A booster shot is an additional dose of a vaccine that gives a “boost” to your immunity and provides better protection from disease. Many routine vaccines require more than one shot to maintain immunity. For example, adults should get a Tdap booster every 10 years; that protects against tetanus, diphtheria and pertussis (whooping cough). With a booster, the immunity that has already been established by a vaccine is stimulated again. So, in a way, the booster serves as a reminder to the immune system’s memory, which can fade over time after vaccination.
Studies show that some people with weakened immune systems do not respond fully to COVID-19 vaccination and that a third dose of the vaccine can boost the levels of antibodies the body makes to fight COVID-19. In addition, the delta variant, which is responsible for almost all COVID-19 cases in the United States right now, is much more easily spread than previous variants of the COVID-19 virus. Higher levels of immunity, such as those produced by a booster shot, may be needed to better protect against this variant, especially for those who are immunocompromised, were vaccinated earlier, or at risk for severe COVID-19.
The CDC has recommended that individuals with a weakened immune system who received either the Pfizer or Moderna vaccines obtain a third dose of either Pfizer or Moderna, as part of a three-dose primary series. Ideally the third dose should be of the same type they have already received. Examples of those with weakened immune systems include, but are not limited to, those who have had a solid organ transplant such as a kidney or lung, have advanced or untreated HIV, or are undergoing chemotherapy or receiving other immune-suppressing treatment.
In addition, the CDC recently expanded eligibility for a booster vaccine to those 65 and older who received the Pfizer shots initially, people 18 years of age or older at high risk for COVID-19 complications, and those who work or live in places where exposure to COVID-19 may be high such as healthcare workers, teachers and day care employees.
If you meet any of these criteria and are a UNC Health patient, you can schedule your appointment for a supplemental dose through My UNC Chart.
Supplemental doses are widely available at local pharmacies and through NC Department of Health and Human Services (NCDHHS). If you are not a UNC Health patient, visit the NCDHHS website for a full listing of where vaccines are available in your community.
If you are unsure if you qualify, talk to your healthcare provider about your medical condition and whether getting a supplemental dose is appropriate for you.
Right now, people who initially received the Johnson & Johnson vaccine are not yet eligible for a booster. There are study data expected shortly that will help the FDA determine how best to boost people who received this vaccine. Similarly, for those who initially were vaccinated with Moderna and are not immunocompromised, a booster dose has not been authorized by the FDA but may be soon.
If you are immunocompromised and eligible for a third dose of a Pfizer or Moderna vaccine, you can receive your third dose 28 days or more after your second dose of either Pfizer or Moderna vaccines. If you are eligible for a booster for a reason other than being immunocompromised, and initially received two doses of the Pfizer vaccine, you can get a booster shot six months or more after the second Pfizer dose.
By being fully vaccinated you still have a much lower risk of becoming seriously ill from COVID-19 than those who are not vaccinated. However, you should continue to follow all of the recommended COVID-19 precautions (remaining in your household bubble, wearing a mask, practicing physical distancing, practicing good hand hygiene and disinfecting potentially contaminated surfaces) to protect your loved ones, coworkers and community.
At this time, it is recommended that you receive supplemental doses from the same vaccine manufacturer as your original vaccination.
This is a legitimate concern. COVID-19 is much more likely to continue to be a major health crisis if many people across the world remain unvaccinated. New variants may emerge in places outside the United States where vaccination is less available, causing illness and death among people there and potentially spreading here. The U.S. federal government has stated there is ample supply of vaccine to provide initial and booster doses in the United States, as well as 500 million to 1 billion doses for donation to other countries in need of vaccines.
Future booster shots may be needed to keep immunity against COVID-19 high and protect against any new variants. Whether or not we will we face a future with annual COVID-19 boosters depends on many factors including the durability of the protection provided by the vaccines, the proportion of the population that remains unvaccinated, and how much COVID-19 is being spread.