The Most Common COVID-19 Booster Shot Questions, Answered

U.S. health officials now recommend another vaccine dose for all Americans. Here's what that means for you.

For months, vaccine manufacturers and health officials have been debating whether booster shots will be necessary to continue to protect Americans against COVID-19, as well as when they might distribute them.

Now the answer is clearer: The Biden administration announced in mid-August that most Americans should get a third shot eight months after they received the second dose of a Pfizer or Moderna mRNA vaccine.

And on Wednesday, Johnson & Johnson reported that a booster shot of its vaccine generates a “rapid and robust” increase in antibodies, and that the company will submit its findings to health agencies.

Naturally, the recent announcements have led to a lot of questions about what this guidance means for fully vaccinated Americans and their loved ones. Here’s what you need to know about this latest news:

1. When will the next round of COVID-19 shots roll out and who gets them?

Many people with weakened immune systems are already eligible for a third dose of the mRNA vaccines, which the Food and Drug Administration authorized last week for “solid organ transplant recipients or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise.”

Boosters for the rest of the population will be available starting this fall, and they’ll be staggered based on when people initially rolled up their sleeves.

“We are prepared to offer booster shots for all Americans beginning the week of September 20 and starting 8 months after an individual’s second dose,” health officials from several federal agencies explained in a joint statement last week.

That means that people who were vaccinated early, including health care workers, nursing home residents and other older adults, will be first in line for boosters.

After that, fully vaccinated individuals will be eligible to get their booster shots eight months after their second dose of the mRNA vaccines. (Can’t remember exactly when you got your second shot? The date is on your COVID-19 vaccine card.)

2. What happens if you got the Johnson & Johnson shot?

The Johnson & Johnson vaccine was not part of the Biden administration’s initial booster plan, although public health and medical experts from the U.S. Department of Health and Human Services said at the time that they anticipated “booster shots will likely be needed for people who received the Johnson & Johnson (J&J) vaccine.”

Now that Johnson & Johnson has released its booster data, it will submit it to the FDA, which is currently evaluating data from Pfizer and Moderna to make recommendations about boosting.

For now, experts tend to advise against getting a shot of the Moderna or Pfizer vaccine if you initially received the Johnson & Johnson shot. Some say there probably isn’t any harm in taking an extra dose, but individuals who got J&J should wait for more official guidance from their doctor or other public health officials before getting a booster.

3. Can you mix manufacturers?

Again, there are a few steps that need to be taken before most non-immunocompromised Americans can start getting their boosters. The FDA has to authorize it, then the Centers for Disease Control and Prevention will look over the evidence and make recommendations for all three vaccines. Only at that point will there be more specific, practical information available about how exactly boosters should be given (and what to avoid).

However, the CDC’s advice for immunocompromised people who are qualified to get a third dose right now is that they should not mix manufacturers. You should get a Pfizer booster shot if you initially received the Pfizer vaccine and a Moderna booster if you got Moderna. (The CDC has said there is “not enough data at this time to determine whether immunocompromised people who received the Johnson & Johnson’s Janssen COVID-19 vaccine also have an improved antibody response following an additional dose of the same vaccine.”)

But the CDC also states that “if the mRNA vaccine product given for the first two doses is not available or is unknown, either mRNA COVID-19 vaccine product may be administered.” For now, it’s reasonable to guess that the same advice will be true for the general public as well.

4. What’s the difference between a ‘booster’ and a ‘third dose’? Are they the same?

Although the terms are often used interchangeably, booster doses and third doses are not exactly the same. Boosters are given to people who have already had a full course of the vaccine and developed a good response; third (or additional) doses are given to people who already had a full course of the vaccine and did not develop a sufficient immune response, like immunocompromised individuals.

It’s unclear right now what the specific dosage recommendations will be for the general public when the next round of shots roll out. That’s something the CDC and FDA will weigh in on as they look through the evidence.

5. Will additional shots reduce breakthrough infections?

Yes. The decision to make another shot available to Americans in the coming months is based on available data that makes it clear that protection against COVID-19 decreases over time. Throw in the delta variant, and “we are starting to see evidence of reduced protection against mild and moderate disease,” health officials said in their statement.

But although breakthrough cases have been increasing, they remain quite rare. The breakthrough rate among people who are fully vaccinated is under 1% in all states that are currently tracking that data. Also, the mRNA vaccines and the Johnson & Johnson shot continue to provide robust protection against the most serious outcomes like hospitalization and death, which is ultimately the primary goal of vaccination.

“The vaccine is still really protective against severe disease,” Adam Ratner, chief of the division of pediatric infectious diseases at Hassenfeld Children’s Hospital at NYU Langone Health, told HuffPost.

“Fully vaccinated folks, in general, are not the ones who are ending up in the hospital, ending up in the intensive care units,” he added. “The idea behind boosting is to make sure that we don’t get to that point.”

Health officials are now recommending COVID-19 booster shots for most Americans.
Health officials are now recommending COVID-19 booster shots for most Americans.

6. Why are these being recommended eight months later?

Recommending another shot eight months after the second shot of the mRNA vaccines is a “best guess based on the available data,” Ratner said. And Johnson & Johnson has indicated it also intends to offer boosters eight months — “or longer” — after the initial dose.

Researchers have been looking closely at antibody titers, which measure the levels of COVID-19 antibodies in the blood. “We conclude that a booster shot will be needed to maximize vaccine-induced protection and prolong its durability,” health officials said.

However, that doesn’t mean that your immunity suddenly falls off a cliff after, say, seven and a half months.

“It’s not something where your immunity just turns off at some point. It’s a spectrum. You have optimum protection some time after that second dose — probably about a month after the second dose — and then you have a slow decay after that,” Ratner said. “But even now, even as we’re getting to that eight-month point for a lot of the highest risk folks, the vaccine is still protective against severe disease.”

Also, immunity is complex and antibodies do not tell the full picture. The COVID vaccines prompt the body to produce T-cells, which really are the main line of defense against the virus, experts say. They are also very difficult to measure, although recent studies suggest they’ve been unaffected by the COVID-19 variants, holding up even better than antibodies have.

7. What will the rollout be like?

Once the CDC and FDA have reviewed the evidence and made their recommendations, there really should not be the same problems with rollout as we saw when the vaccine was first approved.

Vaccine supply is not an issue in the United States in the way it is throughout much of the world. Also, because the shots will be staggered based on when people received their second dose, there shouldn’t be a deluge of people wanting their follow-up shots all at once.

“It’s not going to be a crush of everyone trying to get a booster at the same time,” Ratner said.

8. What should you do if you lost your vaccine card?

It’s recommended that you keep your physical COVID-19 vaccination card in a safe place and that you take a picture of it so you have a record of it. Bring it with you when it’s your turn to get your next shot.

If you misplaced your card, though, don’t stress. Contact your original vaccine provider to see if they can verify your record or get you a replacement. You can also contact your state health department’s immunization information system.

9. What about kids?

Ratner said he thinks it “wouldn’t be surprising” if children between the ages of 12 and 17 — who are currently eligible for vaccination, and who receive the same dosage as adults — also get a third booster eight months after their second dose, though that’s farther off.

And in general, experts have not expressed concern that making boosters available to adults will somehow hamper the vaccine rollout to younger children if and when they’re eligible for the shots, which is expected at some point this fall or winter.

10. Does everyone think this is a good idea?

No. Boosters are controversial from a global equity perspective, with the World Health Organization calling for a moratorium until more people around the world have received a first dose of a vaccine.

And in general, experts say the most important step is making sure that everyone who is eligible for the vaccine gets it in the first place. Only half of the population in the U.S. is fully vaccinated right now, and there are countries in the world where less than 1% of the population is fully vaccinated.

“This is part of the evolution of our understanding of how best to prevent this disease,” Ratner said. “It’s not so surprising to me that we need boosters, and I think this is something to roll with. But we should also focus on getting the people who aren’t vaccinated, vaccinated.”

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.