A correction to an earlier version of this article is appended to the end of the article.
Tens of millions more Americans could soon receive a COVID-19 booster shot after U.S. government advisers on Thursday signed off on expanding the list of those eligible for an extra dose and providing them with more options to get one.
A day after the Food and Drug Administration authorized extra doses of all three vaccines available in the U.S., an advisory panel for the Centers for Disease Control and Prevention followed suit.
Here’s what you should know about their decisions and what it means for the nation’s booster campaign.
What exactly did the FDA and CDC decide?
The FDA and CDC advisory panel made two decisions that could drastically affect the availability of booster shots moving forward.
First, they endorsed using Moderna and Johnson & Johnson COVID-19 vaccines as boosters.
Then they announced that those eligible for an additional dose could soon receive a shot from a different brand than the original one — an approach known as “mix and match.” For example, a person who originally received a shot of the Johnson & Johnson vaccine could get a booster of either Pfizer-BioNTech or Moderna vaccine.
So, when will this all take effect?
CDC Director Dr. Rochelle Walensky will have the final say. If she gives the green light, public health departments and health care facilities will be able to officially start rolling out the extra doses.
Will mixing my vaccines make them less effective?
A federally funded study from the National Institutes of Health on “mixing and matching” of COVID-19 vaccine brands found the approach to be safe and, in the case of those who initially got a one-shot Johnson & Johnson vaccine, even more effective.
In particular, preliminary data from the study revealed that people who received Johnson & Johnson’s single-dose vaccine saw their antibody levels rise 76-fold within 15 days of receiving a booster shot from Moderna and 35-fold after getting a Pfizer booster, compared to a fourfold jump after an additional dose of Johnson & Johnson.
In Britain, where officials authorized mixing and matching of vaccines in certain circumstances in January, the approach has also shown positive results, producing a protective immune response to those who received a dose either from Pfizer or AstraZeneca.
Will mixing my vaccines cause any negative side effects?
Preliminary results from a British study released in June found that those who mixed the Pfizer-BioNTech vaccine and the AstraZeneca-Oxford shot reported more headaches, fevers and chills than participants who received two doses of the same vaccine. But the side effects dissipated within a few days, and the study did not detect any long-term harm caused by the “mix and match” approach.
Who can get a Moderna booster?
The following groups of people can receive a Moderna booster shot — but only if it has been at least six months since they received their last COVID-19 vaccine:
- People 65 and older
- People 18-64 who are at high risk of severe COVID-19 effects because of medical conditions or where they work
Underlying medical conditions that would qualify someone for a booster shot include cancer; chronic lung, kidney or liver disease; diabetes or obesity; dementia; heart disease; weakened immune system; and certain disabilities. Pregnant women and current and former smokers are also eligible, according to the CDC.
Certain workers who are at high risk of exposure to infections also can receive a booster shot, including health care workers, educators, food and agricultural workers, corrections workers and grocery store employees.
Who is eligible for a Johnson & Johnson booster?
All Johnson & Johnson recipients will be eligible for a second shot at least two months after their first.
What’s up with Pfizer boosters?
Last month, the Centers for Disease Control and Prevention approved booster shots of the Pfizer-BioNTech vaccine for those who had received the brand’s preliminary regime at least six months earlier.
Those who are eligible for an extra dose of the Pfizer COVID-19 vaccine are the same as those eligible for a Moderna shot.
- People 65 and older
- Those between the ages of 18-64 who live in long-term care settings, have underlying medical conditions and live or work in high-risk settings such as schools, jails and health care facilities.
When will people younger than 65 without underlying health conditions qualify for Pfizer and Moderna booster shots?
It is unclear at this time. According to the CDC, additional populations “may be recommended to receive a booster shot as more data become available.”
If I get a booster shot, how is it different from the first dose(s) I received?
A third dose of the Moderna COVID-19 vaccine only uses half of the dose in the first two shots. A Pfizer booster shot is identical to the initial vaccine.
Those who get a booster shot from Johnson & Johnson would receive a second full dose of the vaccine.
Can I get a flu shot at the same time as my COVID-19 booster vaccine?
Yes. According to the CDC, the COVID-19 vaccine — whether it’s part of a person’s first regime or a booster shot — can now be administrated at the same time as other vaccines, including flu shots.
CORRECTION: An earlier version of this story stated that the Pfizer booster was “one third” dose of the initial vaccine, which was incorrect. The Pfizer booster is identical to the initial vaccine.
