Confused about whether to get a booster? Health experts share what they’re telling friends and family

A woman wearing a mask and blue scrubs gets a shot in a clinic.
Nurse Alix Zacharski, left, receives a Pfizer COVID-19 booster shot from Douglas Houghton, right, at Jackson Memorial Hospital in Miami on October 5, 2021. AP Photo/Lynne Sladky
  • The CDC recommends COVID-19 booster shots for some groups after six months.
  • But some health experts say there’s probably a longer list of people who could benefit from boosters.
  • Four experts shared what they tell their own friends and family about whether to get boosters, and when.

It’s the question on many Americans’ minds: Should I get a booster shot? And if so, when’s the best time?

Research has shown that COVID-19 vaccines are less effective after about six months against the Delta variant – which represents nearly all cases in the US. That means vulnerable groups may need added protection, though for most people, COVID-19 vaccines are still highly protective against hospitalization and death for at least six months.

The Centers for Disease Control and Prevention recommends booster shots for people ages 65 and up, adults who live or work in settings with high levels of exposure to the virus, and adults with underlying medical conditions.

But health experts say there’s probably a longer list of people who’d benefit from a booster.

Insider asked four experts what advice they’re giving to their own friends and family about whether to get boosted, and when. Most said that young, healthy people in their 20s and 30s likely don’t need boosters even at the six-month mark. But some experts suggested that adults with mild asthma or people in their 40s and 50s might consider a booster after six months, even though they’re not on the CDC list.

Here’s what experts are telling their loved ones.

Experts disagree about the age cutoff

Healthcare worker in mask, smiling, getting booster shot.
A Thai healthcare worker receives a booster dose of Pfizer’s vaccine in Bangkok on August 9, 2021. Vichan Poti/Pacific Press/LightRocket via Getty Images

David O’Connor, a pathology professor at the University of Wisconsin, said there’s little downside to adults of all ages getting a booster.

“I don’t feel bad at all telling those people who are vaccine-willing and vaccine enthusiastic to go out and get boosted if they’re able,” he said.

“We have a choice as we look into the winter,” O’Connor added. “Down one path, we have being reluctant and living with waning immunity, living with cases and the problems that brings with it. Down the other path, we have something that looks more like Israel, where a large fraction of the population is highly protected from being infected in any way with Delta. I don’t know why you would choose the first path when the second path is right in front of us.”

Other experts aren’t so keen on recommending boosters for younger people, though.

“In some people, they can develop an inflammatory response that leads to side effects such as myocarditis,” or inflammation of the heart muscle, Dr. Simon Li, who helps run the Pfizer COVID-19 pediatric vaccine clinical trial at Rutgers University, told Insider.

Li said he’s not recommending booster shots to his siblings, who are in their 40s and have no preexisting conditions.

Gary McLean, a professor of molecular immunology at London Metropolitan University, said people in their 40s and 50s “could explore the possibility of getting a booster.” But people in their 20s and 30s probably don’t need one, he added.

People who are overweight or have mild asthma should get boosters, experts said

Covid inhaler
Nurse Mari Paz takes an asthma inhaler at the Sant Andreu de la Barca Primary Health Care Center in Spain on June 2, 2020. David Ramos/Getty Images

Bernadette Boden-Albala, director of the public-health program at the University of California, Irvine, said she’s giving out the same recommendations as the CDC. She underscored the need for pregnant people to consider boosters, since the risk of dying from COVID-19 is nearly twice as high for pregnant women as for nonpregnant women.

“The rates of death among women who ended up with COVID who were pregnant are just really scary,” Boden-Albala said. “My daughter was pregnant pre-vaccine and it’s a scary, scary thing.”

Experts also agreed that anyone with mild asthma should consider a booster. The CDC only recommends boosters for people with moderate or severe asthma right now. But O’Connor, who has mild asthma, said he’d already scheduled his booster shot.

Some experts weren’t keen on boosters for workers in retail or corporate offices

Woman wearing face mask holds up pink turtleneck sweater while clothes shopping
A woman wearing mask holds up a pink sweater while shopping. Steve Pfost/Newsday RM via Getty Images

People at high risk of getting COVID-19 on the job include first responders, postal workers, public transit workers, and anyone who works in schools, hospitals, correctional facilities, grocery stores, or homeless shelters, according to the CDC. But experts said that list isn’t comprehensive.

“If you’re going to be exposed to the virus, then you’re potentially in a high-risk environment,” O’Connor said. “There’s enough latitude right now that you can self-select yourself into one of those groups, if you are so inclined.”

Other experts noted, though, that retail workers and people returning to corporate offices may not need boosters right away. McLean said those people probably have fewer, shorter interactions with others than doctors or teachers.

Plus, he added, “they can take other precautions, such as allowing fewer people in the environments, wearing face protection, practicing distancing as best they can.”

There’s little benefit to waiting longer than 6 months for a booster

Covid vaccine empty pharmacy
An empty vaccine waiting area at a Walgreens in Miami Beach, Florida. Jeff Greenberg/Universal Images Group/Getty Images

McLean, who got the AstraZeneca vaccine, said he got antibody tested around six months after his second shot and found that his levels were “really low.” That’s consistent with research on the Pfizer vaccine: A study found that coronavirus antibodies waned significantly after six months among nearly 5,000 healthcare workers. (Antibodies aren’t the only form of immunity, though: Vaccines also spur the body to produce T-cells, which help prevent disease.)

Another study found that Pfizer’s shot was just 47% protective against infection after five months, though the vaccine was still 93% effective against hospitalization for up to six months.

“Five, six months after double-jab, immunity tends to wane, and it’s a good time for a booster,” McLean said, adding, “That could be extended to eight without hopefully too many dramatic effects, but I think tightening it up is better.”

O’Connor said it may be good to get a booster before winter, when more people will travel and congregate indoors.

“The idea that you should wait and have lesser protection – I don’t understand the argument,” he said.

One expert recommended Pfizer or Moderna boosters over J&J

Man in a mask getting his third booster shot of Pfizer vaccine injected into his right arm by a healthcare worker (also masked).
A man receives a booster shot at the VA Hospital in Hines, Illinois, September 24, 2021. Scott Olson/Getty Images

The CDC advises anyone who got Johnson & Johnson’s single-dose vaccine at least two months ago to get boosted. The agency’s latest guidelines say that people can choose any vaccine for their booster.

O’Connor said he’s telling friends and family who received one dose of J&J to get a dose of Pfizer or Moderna – though “a J&J booster is better than none at all,” he said.

Those who got mRNA vaccines can mix and match too, he said, though it probably doesn’t matter.

“If you had Moderna and you get Pfizer, it’s fine. If you had Pfizer and you get Pfizer, it’s fine. If you had Pfizer and you get Moderna, fine,” O’Connor said. “The sooner that we stop brand-shopping the vaccines, the better.”