- Three doses of any combination of COVID-19 vaccines work similarly well at preventing infection and hospitalization, research shows.
- With the appearance of the Omicron variants, three doses offer stronger protection than two doses.
- Adults 50 years and older and some immunocompromised people are eligible for a second booster.
Three doses of the same COVID-19 vaccine or a combination of different types work similarly well at preventing infections and hospital admissions, even those caused by different variants, a May 31, 2022 study in
The results also suggest that the number of vaccine doses is the key to providing the strongest immune protection, rather than a specific combination of vaccine types — with more protection offered by three doses than two.
Three doses are especially needed since the emergence of the Omicron variants, said researchers, which spread rapidly and overcome some of the immune protection offered by vaccination and prior immunity.
Researchers reviewed more than 50 previous studies looking at the protection offered by different combinations of vaccine courses, including boosters.
These studies only included mRNA (Moderna and Pfizer-BioNTech) and adenoviral vector vaccines (Johnson & Johnson and Oxford-AstraZeneca).
In October 2021, the Centers for Disease Control and Prevention (CDC) approved the use of mix-and-match COVID-19 boosters for Americans at high risk of severe illness or infection.
Currently, the agency recommends either of the mRNA COVID-19 vaccines authorized in the United States — Pfizer-BioNTech or Moderna — as a booster, regardless of which vaccine people received initially, including the J&J vaccine.
“For persons who have received the J&J vaccine, getting a booster with one of the mRNA vaccines may be better than getting another J&J booster,” said Dr. Shobha Swaminathan, an associate professor and infectious disease physician at Rutgers New Jersey Medical School.
While the mRNA vaccines are preferred for the booster, the J&J vaccine may be appropriate in
Here are a few things to know about who is eligible for a booster and when you should get one.
The CDC
Some
In addition, the CDC recommends that some people also receive a second booster — adults ages 50 years and older and people ages 12 years and older who are moderately or severely immunocompromised.
The CDC considers you “up to date” with the COVID-19 vaccine when you have received all boosters recommended for you.
Dr. Jay Varkey, an associate professor of infectious diseases at Emory University School of Medicine, said even though boosters have been rolled out in the United States, this does not mean the COVID-19 vaccines are not working.
“They are very effective at preventing death from COVID, and they’re very effective at preventing serious illness that requires people to get hospitalized for COVID,” he said in a media briefing.
“[Boosters are] really [about] trying to enhance protection from infection,” he added, especially for those most at risk.
Modernaor Pfizer-BioNTech
For people who received mRNA COVID-19 vaccines for the primary series, the CDC recommends a booster of either the Pfizer-BioNTech or Moderna COVID-19 vaccine with the following timing:
- 1st booster: Most people should receive a booster at least 5 months after they complete the primary series. People who are moderately or severely immunocompromised should receive a booster at least 3 months after the primary series.
- 2nd booster: Adults 50 years and older and people who are moderately or severely immunocompromised should receive a second booster at least 4 months after the first booster.
Johnson & Johnson
For people who received the J&J COVID-19 vaccine for the primary dose, the CDC recommends a booster of either the Pfizer-BioNTech or Moderna COVID-19 vaccine with the following timing:
- 1st booster: Most people should receive a booster at least 2 months after the primary dose. People who are moderately or severely immunocompromised should receive a booster at least 2 months after the additional dose of an mRNA vaccine.
- 2nd booster: Adults 50 years and older and people who are moderately or severely immunocompromised should receive a second booster at least 4 months after the first booster.
Pfizer-BioNTech
For children and teens ages 12 to 17 years, the CDC recommends a booster of the Pfizer-BioNTech COVID-19 vaccine on the following schedule:
- 1st booster: Most children and teens should receive a booster at least 5 months after completing the primary series. Those who are moderately or severely immunocompromised should receive a booster at least 3 months after completing the primary series.
- 2nd booster: Children and teens who are moderately or severely immunocompromised should receive a second booster at least 4 months after the first booster.
Pfizer-BioNTech
For children ages 5 to 11 years, the CDC recommends a booster of the Pfizer-BioNTech COVID-19 vaccine on the following schedule:
- 1st booster: Most children should receive a booster at least 5 months after completing the primary series. Those who are moderately or severely immunocompromised should receive a booster at least 3 months after completing the primary series.
- 2nd booster: The CDC does not recommend a second booster for this age group at this time.
It is never too late to schedule your COVID-19 vaccine booster. To find a vaccination location, check with your doctor or local pharmacy. You can also visit Vaccines.gov or contact your
If you have questions about boosters, Varkey recommends that you seek out trusted medical advice.
“This decision on what to get boosted with will be an individual decision that most people should make with the advice of their doctor,” he said.