The U.S. Food and Drug Administration has authorized updated COVID-19 boosters that may better protect against currently circulating viruses causing thousands of infections and hundreds of deaths every day in the U.S. These vaccines will target the original strain of the coronavirus and the highly contagious omicron subvariants BA.4 and BA.5.

Do you need to get the new booster?

Dr. John Greene, chair of the Infectious Diseases Program at Moffitt Cancer Center, weighs in on what you need to know about the new shot.

What are bivalent vaccines?

Bivalent vaccines target two different strains. The updated Pfizer and Moderna boosters target both the original coronavirus strain and the omicron BA.4 and BA.5 subvariants.

Why are new shots needed?

As the coronavirus has evolved, these changes have helped it evade antibodies made against older versions of the virus and previous versions of the vaccine. This has led to more reinfections and breakthrough infections.

Who are the shots for?

Anyone who has received the two-shot primary series of Pfizer and Moderna, as well as the single-shot Johnson & Johnson vaccine, is eligible, regardless of whether they received any or all of the recommended booster shots. The updated Pfizer shot is authorized for those 12 and older, and the updated Moderna shot is authorized for those 18 and older. Both shots can be given starting two months after a primary vaccination series or booster.

When will the shots be available?

Now that the Centers for Disease Control has approved the updated boosters, shots could be available as soon as this weekend.

Where can I get one? How much is it?

Doctor’s offices, hospitals, pharmacies and community health clinics will have the shots. Find locations at vaccines.gov. The federal government has purchased the updated boosters, which will be free to consumers. The booster can be given at the same time as other vaccines, such as the annual flu shot.

Should I get an updated booster of the same brand as my primary series?

The Centers for Disease Control says people 12 and older may get a booster that is different from their primary series, as long as the booster is Pfizer-BioNTech or Moderna. “Some studies support mixing vaccines with an equal or sometimes better immune response,” Greene said. Children ages 5-11 who got a Pfizer-BioNTech primary series must also get a Pfizer-BioNTech booster, according to the CDC.

What are the side effects?

The side effects will be similar to those from the current vaccine, including redness and swelling at the injection site, fatigue, headache and muscle soreness.

Will there be a surge in COVID cases this fall?

“COVID-19 is unpredictable, but many experts believe the virus will eventually act like the flu virus and become seasonal every winter,” Greene said.

How well do the updated vaccines work?

The updated vaccines are expected to be 90% effective. The booster will take about two weeks to be fully effective.

What if I recently had COVID? Do I still need to get an updated booster?

People should wait 90 days, at which time the immune response from the infecting COVID-19 strain wanes and you are susceptible to reinfection.

If I had COVID a year ago, do I still have immunity?

Probably not. COVID-19 immunity wanes to a level that does not protect from reinfection within six to 12 months of illness.

If I just got a booster of the original vaccine, should I get the new shot now?

No. The FDA recommends that people should wait at least two months before getting the updated booster. Getting the new booster too soon may limit its effectiveness.

If I have not been vaccinated, can I start the process now?

Yes, you can get the updated vaccine similar to getting your annual flu shot.

I have cancer. What COVID precautions do I need to take?

“Make sure you are taking the same precautions since the onset of the pandemic. Avoid crowds and poorly ventilated rooms with other people, wear a mask around others, and wash your hands well and frequently,” Greene said.

Will an updated COVID vaccine every year become the norm, similar to flu shots?

“Experts are predicting the need for an annual COVID-19 vaccine that captures the major circulating strains at the time just like is done for the flu virus,” Greene said.

Today, we amended the authorizations of the Moderna COVID-19 Vaccine and the Pfizer-BioNTech COVID-19 Vaccine to authorize updated formulations of the vaccines for use as a single booster dose at least two months following primary or booster vaccination. https://t.co/1mS2TNqXaA pic.twitter.com/xJA1baopLh

— U.S. FDA (@US_FDA) August 31, 2022