What’s the difference between a third COVID-19 dose and booster shots?

Updated Oct. 22: The U.S. Centers for Disease Control and Prevention now recommends the COVID-19 vaccine boosters for recipients of the Moderna and Johnson & Johnson shots, and said Americans can choose a different shot from their original inoculation as a booster.

Vaccine providers across Iowa now offering eligible Iowans additional doses of COVID-19 vaccines to help boost immunity against the ongoing spread of the coronavirus.

But what’s the difference between booster doses and the third shot recommended for certain Americans by federal health officials?

Mike Brownlee, associate director and chief pharmacy officer at University of Iowa Hospitals and Clinics, explained what Iowans need to know about the additional COVID-19 vaccine doses.

Who is eligible for a COVID-19 booster shot?

Earlier this month, the federal Centers for Disease Control and Prevention and the Food and Drug Administration authorized Pfizer-BioNTech COVID-19 booster shots for certain individuals, including:

In addition, federal officials also recommended that other groups may benefit from the booster shot. These include:

Pfizer was the first vaccine authorized for booster shots.

Can I get a booster if I had Moderna or Johnson & Johnson vaccines?

Both the CDC and FDA backed recommendations to authorize Moderna and Johnson & Johnson booster shots, meaning Americans can start getting those shots beginning Oct. 22.

Federal officials say a Johnson & Johnson booster is recommended for those aged 18 and older at least two months after their initial immunization.

Criteria for those eligible for Moderna booster shots is the same criteria as Pfizer boosters:

The booster may also be administered to:

Can I mix and match boosters?

You can, according to federal health recommendations.

According to the CDC’s latest guidance, eligible individuals can receive any of the three available booster doses, regardless of whatever brand of vaccine they received in their initial immunization series.

What’s the difference between the booster shot and a third dose of the vaccine?

A booster shot is another dose of the vaccine given to someone who already is fully immunized against COVID-19. A booster dose is given six months after the second dose, which when a person begins experiencing waning immunity against the coronavirus, experts say.

But that’s different from a third dose of a mRNA vaccine that was recommended by the CDC and the FDA this past month for certain immunocompromised Americans.

Studies have shown the first two doses of the COVID-19 vaccine is not enough for immunocompromised individuals to build up strong protection against the coronavirus, Brownlee said. Therefore, they need a third dose of the vaccine.

“So to be considered fully vaccinated now, those that are immunocompromised need three doses,” Brownlee said.

The third shot for immunocompromised Americans is the same dose amount as the first two doses, Brownlee said.

Pfizer’s booster dose is also the same amount of vaccine as the first two shots. However, the FDA may authorize just a half-dose for the Moderna booster shot, Bloomberg reported in late September.

Who can get a third dose of the COVID-19 vaccine?

At this time, those who are moderately or severely immunocompromised, including those on a medication or treatment that suppresses their immune systems, should receive a third dose. They make up about 3 percent of the U.S. population, according to the CDC.

They can receive the third dose of either Pfizer or Moderna at least 28 days after the second dose. Public health officials say individuals can receive the third shot anytime after that 4-week interval. The third dose should be from the same vaccine series as their first two shots, federal officials recommend.

Federal officials still are studying data to determine whether those who received a Johnson and Johnson vaccine need an additional dose.

Those who received an additional vaccine dose are not eligible to also receive a booster shot.

UIHC officials have built in an alert to their electronic medical record system to notify providers when their patients may be eligible for the third dose, Brownlee said. However, he also said it's too complicated for the UIHC to reach out to all its patients.

“At a minimum, have that conversation with your provider to ask that question,” Brownlee said. “We're just trying to make it available in the community and we're trying to create opportunities for our patients to talk to their providers in a meaningful way.”

If I’m fully vaccinated, why do I need a booster dose?

New research has found the vaccine’s ability to protect individuals — especially those who are aged 65 and older or who have underlying health conditions — from serious coronavirus-related illness and hospitalization declines over time, Brownlee said.

This is called waning immunity. Most vaccines in use have a booster for declining antibodies, experts say.

“It’s not that the vaccine is not effective anymore — it’s still very, very effective,” Brownlee said. “It’s just that the booster is to give your immune system that final kick to get it back up to that high level of 95 percent efficacy in helping reduce the spread of the virus.”

Brownlee said experts continue to study if a booster dose is needed for the general population.

Where can I find a booster shot, if I qualify?

Booster shots are offered at most vaccine providers, including health care clinics and national pharmacy chains such as CVS, Walgreens and Hy-Vee.

Iowans can find an available vaccine appointment near them by visiting the state’s COVID-19 vaccine finder, vaccinate.iowa.gov.

There is no shortage of the supply at this time, Brownlee said, so those who qualify should not have to wait for their dose.

Brownlee said Iowans should follow the criteria laid out by federal health officials around booster doses and the third dose for immunocompromised individuals.

“We’ve actually seen patients scheduling themselves into slots for immunocompromised patients to try to get the booster because they think they need one, when in reality they may not fall into that criteria,” Brownlee said.

“We want to encourage the community to follow the rules until we have more information from the FDA and CDC.”

Comments: (319) 398-8469; michaela.ramm@thegazette.com

Source: Iowa Board of Pharmacy