Experts and public health agencies, including the Centers for Disease Control and Prevention (CDC), are recommending COVID-19 booster shots for fully vaccinated individuals as highly-contagious omicron subvariants such as BA.5 remain dominant in the United States.
Booster shots have prompted a lot of questions via email and text message from our VERIFY viewers, including who needs one and when, whether immunocompromised people need a second booster, and how effective boosters are against BA.5.
We are breaking down what we can VERIFY about COVID-19 booster shots and additional doses.
- Centers for Disease Control and Prevention (CDC)
- U.S. Food and Drug Administration
- World Health Organization (WHO)
- Johns Hopkins Medicine
- Study on antibody evasion of omicron subvariants published in Nature
- Payal Kohli, M.D., assistant clinical professor of medicine at the University of Colorado in the Department of Cardiology and founder of Cherry Creek Heart
- Who can get a second booster shot: The CDC recommends two booster shots for adults ages 50 and older, and some “moderately to severely” immunocompromised people ages 12 years and older. People within this group can get a second booster shot at least four months after their first booster.
- How effective are booster shots against BA.5: BA.5 is more resistant to antibody protection in people who are vaccinated and boosted than previous subvariants, a study found. But booster shots can still prevent hospitalization from severe COVID-19 illness and death.
- What booster shots mean for the “fully vaccinated” definition: The CDC definition of fully vaccinated doesn’t include the booster shot. You are still considered fully vaccinated after your second dose in a two-shot series or two weeks after the single-dose J&J vaccine.
WHAT WE KNOW
Who needs their first COVID-19 booster shot and when?
If you got the Pfizer vaccine
Everyone 5 and older who received the Pfizer mRNA COVID-19 vaccine should get a booster shot at least five months after getting their second dose of the vaccine, the CDC says.
If you got the Moderna vaccine
Adults who received the Moderna vaccine should also get a booster shot at least five months after their second dose. Boosters are not recommended by the CDC for any children or teens who have completed their primary series of the Moderna vaccine.
If you got the Johnson & Johnson vaccine
Those who received the one-dose Johnson & Johnson (J&J) vaccine should get a booster shot at least two months later. Pfizer or Moderna shots are preferred as that booster in most situations, according to the CDC.
If you got the Novavax vaccine
The CDC and American Medical Association both say Novavax’s vaccine isn’t authorized for use as a COVID-19 booster dose at this time.
In late May, Novavax announced that it would begin phase 3 of a clinical trial to determine the effectiveness of its omicron strain vaccine as a booster dose in producing better immune responses to the omicron variant compared to its newly authorized vaccine without a booster. Novavax’s COVID-19 vaccine was recently authorized as a two-dose primary series, but not as a booster shot.
Can kids under 5 years old get a booster shot?
Though the FDA has authorized the Pfizer and Moderna COVID-19 vaccines for children under 5 years of age, boosters aren’t recommended by the CDC for anyone in this age group right now.
Can you mix and match brands for your booster shot?
You can mix and match brands for your booster shot, according to the CDC and Johns Hopkins Medicine. The U.S. Food and Drug Administration (FDA) has authorized Pfizer, Moderna and J&J vaccine boosters, but the CDC is only recommending Pfizer and Moderna for booster shots in most situations.
Who can get a second COVID-19 booster shot?
The CDC recommends two booster shots for adults ages 50 and older, and some “moderately to severely” immunocompromised people ages 12 years and older.
People within this group can get a second booster shot at least four months after their first booster, no matter what brand of shots they’ve received in the past, the CDC and FDA say.
Pfizer’s vaccine is authorized as a second booster for children ages 12 and older who are immunocompromised. Moderna’s vaccine is only authorized as a second booster for immunocompromised people who are 18 and older.
Those 50 and older can receive a second booster dose of either Pfizer or Moderna.
Here’s who the CDC considers moderately or severely immunocompromised:
- Receiving active cancer treatment for tumors or blood cancers
- Received an organ transplant and are taking medicine to suppress the immune system
- Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
- Moderate or severe primary immunodeficiency (such as DiGeorge syndrome and Wiskott-Aldrich syndrome)
- Advanced or untreated HIV infection
- Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response
People should talk to their healthcare provider about their medical condition and whether they should get an additional primary shot, the CDC says.
How effective are booster shots against the dominant BA.5 subvariant?
A recent study published in Nature, an international research journal, found that the BA.4 and BA.5 omicron subvariants are about four times more resistant than earlier omicron strains to antibody protection in people who are vaccinated and boosted. That means the subvariants are “more likely to lead to vaccine breakthrough infections” than those that came before them, the researchers said.
However, booster shots are still effective in preventing severe outcomes such as hospitalization and death, even among people who contract the BA.5 subvariant.
“We now know that our neutralizing antibodies, those ones that we get from the boosters, are not as effective at preventing infection. They're still effective in preventing you from getting super sick,” Payal Kohli, M.D., a cardiologist and professor, told VERIFY. “[Boosters] just don't work quite as well as they did…for prior variants where the immune evasion was not there.”
The World Health Organization says on its website that COVID-19 vaccines are “very effective at preventing serious illness, hospitalization and death from all current virus variants.”
“[Vaccines] are less effective at protecting you against infection and mild disease than they were for earlier virus variants; but if you do get ill after being vaccinated, your symptoms are more likely to be mild,” according to the WHO.
Since experts have found that current vaccines are less effective at preventing infection of omicron, the FDA’s vaccine advisory committee recently voted in favor of including an omicron component in COVID-19 vaccines that would be used for boosters in the fall of 2022.
Are booster shots the same dose as the original vaccines?
The Pfizer and Johnson and Johnson COVID-19 booster shots use the same ingredients as the previous vaccines, the CDC says.
The Moderna booster shot contains half of the original vaccine dose.
Memorial Sloan Kettering Cancer Center writes on its website that data submitted by Moderna to the FDA and CDC shows that a half-dose booster shot “effectively strengthens a person’s immunity against COVID-19 and its variant.” Moderna also said the half-dose booster may reduce side effects.
How long should you wait to get a booster after contracting COVID-19?
If you have recovered from COVID-19 and are no longer symptomatic, you can get a booster shot, experts told VERIFY sister station WCNC. Doctors at Houston Methodist also recommend that a person waits to get a booster shot until they are out of the five-day isolation period.
There is one caveat, though. If you received monoclonal antibody treatment while sick with COVID-19, you need to wait 90 days before getting a booster shot.
Are you still considered “fully vaccinated” if you haven’t received a booster shot?
Yes. The CDC says its definition of fully vaccinated hasn’t changed and doesn’t include the booster shot. You are still considered fully vaccinated after your second dose in a two-shot series, such as Pfizer or Moderna, or two weeks after the single-dose J&J vaccine. There is “no time limit after vaccination on your fully vaccinated status,” the Mayo Clinic says on its website.
However, those who are fully vaccinated but haven’t received a booster shot are not “optimally protected” from COVID-19, according to the CDC. A person who is “up to date” has received all recommended COVID-19 vaccines, including any booster doses when they are eligible, the public health agency says.
Do you have questions about booster shots? Send the VERIFY team an email to firstname.lastname@example.org.