How does a booster shot work?
Not all vaccines work the same. For some vaccines, immunity begins to wane over time and another dose is needed to “boost” your immune response against that disease. A booster helps ensure your immunity stays as strong as possible against infection over time. Many other vaccine-preventable diseases need boosters over time, such as tetanus, diphtheria, meningococcal infection, and pertussis. In some cases, it’s a single booster, and in others (like tetanus) recurrent boosters are needed. It’s not yet clear whether additional boosters will be needed for individuals who get a booster now against COVID-19 — we will have to follow the science over time to learn more.
Is a booster the same as a third dose?
These terms are often used interchangeably, but “booster” means something slightly different from a “third dose”. For COVID-19 mRNA vaccines, a person with a normal immune system might only need two doses, but someone with a severely weakened immune system needs an additional dose (a third dose) to build up an initial strong immune response. People who have compromised immune systems and received an mRNA vaccine earlier this year have already been authorized to receive a third COVID mRNA shot since August.
Why are boosters being authorized for some groups now?
Experts from the FDA and CDC have reviewed the available data to evaluate the continued effectiveness of two doses of the Pfizer vaccine over time. What they found was that two doses do continue to provide protection, in particular against hospitalization and death, but that over time there is a greater risk of infection and some increased risk of severe outcomes especially for older adults. They also studied data to make sure a booster dose is safe and effectively strengthens a person’s immune response.
Since older adults and those with underlying health issues face the highest risk of severe illness from COVID infection, FDA and CDC expert panels are recommending boosters for these groups, along with residents of long-term care settings who are at increased risk of exposure and often include individuals who are older with underlying medical conditions. Although the vaccine is still effective against severe illness, healthcare workers and other essential frontline personnel are at increased risk of exposure and often cannot work if they develop even mild illness, so the CDC also suggests this group consider getting a booster dose.
Who is eligible to receive a booster dose right now?
So far, only people who have already received two doses of the Pfizer vaccine qualify for a booster dose (because that is the data the experts have looked at so far). The CDC recommends that the following groups get a Pfizer COVID-19 booster shot:
- people 65 years and older and residents in long-term care settings
- people 50–64 years old with underlying medical conditions
The CDC also suggests that the following groups consider getting a booster but should talk to their healthcare provider about their individual benefits and risks:
- people aged 18–49 years with underlying medical conditions
- people aged 18-64 years who are at increased risk for COVID-19 exposure and transmission because of an occupational or institutional setting.
- Occupational settings include anyone who works indoors and regularly comes into contact with people of unknown vaccination status, such as teachers, healthcare workers, and transit workers.
- Institutional settings include employees and residents of congregate facilities such as detention centers, group homes, and shelters.
Will I need to show proof of eligibility to get a booster?
No. RHHD and other providers across our region will not ask you to prove that you qualify based on age, medical condition, workplace, etc. in order to get a booster dose. However, your vaccine provider may check state records to make sure you previously received the Pfizer vaccine (not Moderna or Johnson & Johnson) and that it has been more than six months since you received your second dose before administering a booster.
Why aren’t booster doses open to all fully vaccinated people?
Looking at the data currently available, FDA and CDC found that, because the vaccine still showed effectiveness against severe illness and death, a booster was not necessary for lower risk fully vaccinated adults or kids 12 and older at this time. Boosters may be recommended for additional groups later as new data becomes available.
Why are only Pfizer boosters authorized?
Experts at the FDA and CDC looked specifically at data from the Pfizer vaccine booster. In the coming weeks, the FDA and CDC will go through the same process of studying whether a booster is needed, safe, and boosts the immune response for the Modern and Johnson & Johnson vaccine as well as data about the use of a booster from a different vaccine manufacturer than your previous doses (for example, receiving a Pfizer booster after two shots of the Moderna or a single shot of the Johnson & Johnson vaccine).
What if I wait a while to get a booster?
You can get your booster anytime after six months following your second dose, but you don’t need to feel anxious about getting a booster at exactly the six-month mark. It’s important to know that your immune response to COVID does not stop abruptly: your protection against infection may weaken over time but will not go away completely, and the vaccine is still effective at preventing severe infection and death. However, people in groups currently recommended for a booster should consider scheduling their shot once the six-month mark passes after their second dose.
Can I mix and match vaccine brands for a booster?
No. For now, the FDA and CDC have not authorized mixing vaccine brands for boosters, and the safety and effectiveness of mixing vaccine brands haven’t been determined yet. Currently, only people who have completed their initial COVID-19 vaccine series with two doses of the Pfizer vaccine at least 6 months ago should get a Pfizer booster. We anticipate information about Moderna and Johnson & Johnson coming in the next few weeks.