• The U.S. Food and Drug Administration (FDA) has approved updated boosters for messenger RNA (mRNA) COVID-19 vaccines from Pfizer and Moderna.
• These new vaccine boosters offer protection against newer variants of the coronavirus, which have been linked to breakthrough cases of COVID-19.
• People ages 5 and up, including individuals who are moderately or severely immunocompromised, are eligible to receive the updated booster.

The FDA has approved newly formulated boosters for the mRNA COVID-19 vaccines from Pfizer and Moderna. These new shots give vaccine recipients — including those who are immunocompromised — extra protection against variants of SARS-CoV-2, the virus that causes COVID-19. These variants spread more quickly from person to person and can be resistant to the original vaccines. The spread of the omicron variants has led to a spike in breakthrough cases when people become infected with coronavirus despite being fully vaccinated.

Following the FDA’s approval, the Centers for Disease Control and Prevention (CDC) recommended the updated boosters. “The updated COVID-19 boosters are formulated to better protect against the most recently circulating COVID-19 variant,” said Dr. Rochelle Walensky, director of the CDC, in a statement. “They can help restore protection that has waned since previous vaccination and were designed to provide broader protection against newer variants.”

Walensky noted that the CDC’s recommendation is based on “comprehensive scientific evaluation and robust scientific discussion.”

“If you are eligible, there is no bad time to get your COVID-19 booster and I strongly encourage you to receive it,” she said.

The updated COVID-19 boosters are available now throughout the U.S. Vaccines.gov offers a tool to find nearby locations to receive the booster.

How Are These Boosters Different From the Previous Ones?

People who’ve followed the recommended COVID-19 vaccine schedule are no strangers to booster shots. Their purpose is to keep your immune system primed with the necessary antibodies to fight the coronavirus. These antibodies naturally diminish over time.

The first set of FDA-authorized mRNA vaccines contained a sort of blueprint of the spike protein found on the original strain of the coronavirus. Using the blueprint in the vaccine, a person’s immune system learns what the coronavirus looks like and how to fight it. The original mRNA vaccines are called monovalent vaccines because they contained blueprints for just one virus component.

The new versions are called bivalent vaccines because they contain blueprints for two different spike protein components: one from the original version of the coronavirus and a new one found on the BA.4 and BA.5 omicron subvariants. These are the subvariants that have proven resistant to the original vaccines. By getting an updated bivalent booster, your immune system will be able to recognize and fight both the older and newer, more prevalent subvariants.

Who Can Get the Updated Booster?

Bivalent booster guidance from the FDA and CDC varies depending on a person’s age, vaccination status, and whether or not they’re moderately or severely immunocompromised — that is, whether they have a weakened immune system.

Guidance for the General Population

Per the CDC and FDA, people 6 and up who are fully vaccinated and who aren’t immunocompromised are eligible for a single booster dose of the bivalent Moderna COVID-19 vaccine. People 5 and up who are fully vaccinated and who aren’t immunocompromised are eligible for a single booster dose of the bivalent Pfizer COVID-19 vaccine.

Before getting an updated booster, you'll need to wait at least two months after completing your initial vaccine series or receiving a booster dose of a monovalent COVID-19 vaccine.

The booster you receive doesn’t need to be from the same manufacturer as your primary series or previous boosters.

Public health experts advise people who’ve recently contracted COVID-19 to wait until they are fully recovered from the acute illness before getting an updated booster. The CDC has said that getting a booster between the time you first recover from your infection up to three months later may boost your immune response.

“If you’ve had a recent infection or were recently vaccinated, it’s reasonable to wait a few months,” said White House COVID-19 Response Coordinator Dr. Ashish Jha during a Sept. 6 press conference.

The agency offers a COVID-19 booster tool to help people determine if and when they can get a booster.

Guidance for People Who Are Immunocompromised

People who are moderately or severely immunocompromised due to other health conditions face a higher risk of severe illness or death from COVID-19, according to the CDC. This includes people who:

• Have been undergoing active cancer treatment for tumors or cancers of the blood
• Have received an organ transplant and are taking medicine to suppress the immune system
• Have received chimeric antigen receptor (CAR) T-cell therapy or received a stem cell transplant within the past two years
• Have moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome)
• Have advanced or untreated HIV infection
• Are taking high-dose corticosteroids or other drugs that may suppress the immune response

The CDC recommends people ages 12 and up who are immunocompromised receive an updated booster to restore protection from their previous vaccine and boost protection against the new variants.

Are the Updated Boosters Safe and Effective?

According to the FDA, bivalent COVID-19 vaccines — that is, vaccines containing the old and new spike proteins — are safe and effective, based on results from human trials. Notably, those tests used a bivalent vaccine containing an earlier omicron subvariant called omicron BA.1. Currently, the newly approved vaccines containing the omicron BA.4 and BA.5 subvariants have been tested only on animals.

Nevertheless, the FDA and CDC believe the positive test results of the older bivalent vaccine are relevant to the newly approved ones, as they were all developed using the same manufacturing process.

It’s not unusual for the FDA to approve an updated vaccine that hasn’t undergone tests on humans. The most common example is the flu vaccine, which is updated annually based on what scientists predict will be the most common version of the flu virus that year. Those flu shots are generally updated using the same manufacturing process that’s consistently yielded safe, effective vaccines.

Last Booster for the Next Year?

U.S. health officials predict people who receive an updated COVID-19 booster won’t need another booster for a year. According to Dr. Jha, people may be able to receive a single booster each year that’s been updated to combat the most prevalent coronavirus variants. “Barring any new variant curveballs, for a large majority of Americans, we are moving to a point where a single, annual COVID shot should provide a high degree of protection against serious illness all year,” he said during a press briefing.

Booster Side Effects

Potential side effects, both those that are common and rare but serious, are similar to previous versions of the vaccine. Side effects may feel like flu symptoms — including fatigue, pain, and fever — and can affect your ability to do daily activities. It may be helpful to schedule your vaccination on a day when you’ll be able to rest afterward.

Side effects generally fade within a few days. Applying a cool, clean washcloth to the injection site can reduce discomfort. It may also help to move your arm around to relax your muscles and lessen soreness. Try to drink plenty of fluids after the vaccination.

Contact your health care provider if these side effects last longer than a few days, if they seem especially intense or worrisome, or if your injection side is still red and irritated 24 hours after your shot.

The Bottom Line

The consensus among health experts is that the potentially severe side effects from a COVID-19 vaccine are extremely rare. “The benefits of COVID-19 vaccination outweigh the known and potential risks,” notes the CDC.

People who aren’t fully vaccinated face a higher risk of developing a severe COVID-19 infection, requiring hospitalization, or dying from the disease.

If you have questions or concerns about getting the updated booster, speak with your health care provider.

Find Your Team

On myCOVIDteam, the online social network for people with COVID-19 and their loved ones, more than 7,000 members come together to ask questions, give advice, and share their stories with others who understand life with COVID-19.

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