With boosters of all available COVID-19 vaccines in the U.S. now authorized, vaccination sites throughout California have begun administering the extra doses to shore up immunity against the virus.

Last week, the Centers for Disease Control and Prevention’s advisory committee approved boosters for Moderna and Johnson & Johnson vaccines, and said that people can “mix and match” when getting the extra dose — regardless of which type they got first. Boosters for Pfizer’s vaccine had previously received the green light.

All three of the vaccines continue to offer strong protection against hospitalizations and death from COVID-19, and health authorities hope boosters will offer more protection.

Here’s what to know about getting the booster dose, including who’s eligible, what jobs qualify workers for an additional dose, when to get the booster, how to get the booster, mixing and matching vaccines, what side effects to expect and how to update your digital vaccine record after getting the booster dose:

Who is eligible for a booster?

For both Pfizer and Moderna, a booster dose is available for those who received their second dose at least six months ago, and fall into any of these categories:

  • Are 65 years old or older
  • Living in a long-term care setting (must be 18+)
  • Have underlying medical conditions (must be 18+)
  • Work or live in high-risk settings (must be 18+)
  • Are at increased risk due to social inequity (must be 18+)

For Johnson & Johnson, a booster dose is recommended if you:

  • Got your first dose of the Johnson & Johnson vaccine at least two months ago, and
  • Are 18 years old or older 

Vaccination sites won’t require proof of eligibility, outside of self-attestation. 

What jobs qualify workers for boosters?

High-risk jobs include:

  • First responders (health care workers, firefighters, police, congregate care staff)
  • Education staff (teachers, support staff, daycare workers)
  • Food and agriculture workers
  • Manufacturing workers
  • Corrections workers
  • U.S. Postal Service workers
  • Public transit workers
  • Grocery store workers

Frontline workers, including restaurant staff, grocery store workers, police and firefighters, can also consider getting the booster dose, according to state officials.

When is it possible to get a booster dose?

Booster doses are authorized for a specific time frame, and people are advised to get them as soon as they’re eligible, in order to maintain strong immunity against COVID-19.

For Pfizer and Moderna recipients: booster doses should be given at least six months after getting the second shot.

For Johnson & Johnson recipients: booster doses should be administered at least two months later.

Here’s an online calculator to see when you’d qualify for the booster.

How to get the booster

Health care providers, clinics and pharmacies throughout the state are dispensing the additional dose.

While at this point, appointments aren’t needed at many vaccination sites, Californians can visit MyTurn.ca.gov, or call 833-422-4255 to make an appointment or find a nearby walk-in vaccine clinic.

Residents can also visit their county’s vaccine portals for more information:

Can you get a booster dose from a different brand than what you originally got?

Yes, a single dose of any of the available COVID-19 vaccines may be administered as a booster.

Eligible Johnson & Johnson vaccine recipients can now get a dose of the J&J, Pfizer or Moderna vaccines at least two months after receiving their first shot.

Meanwhile, Moderna and Pfizer vaccine recipients can get a booster from any of the authorized vaccines at least six months after completing their primary vaccinations.

What side effects should be expected after the booster?

Health authorities say the side effects from booster doses should be the same mild side effects experienced when receiving the initial vaccine doses: A sore arm at the injection site, and mild flu-like symptoms.

What about updating digital vaccine records?

Digital COVID-19 vaccine records will not automatically update once people get the boosters.

Californians will have to download a new version if they want their record to show that they got a booster dose. State officials recommend waiting 14 days before trying to download another one.

Digital records can be downloaded using the state’s Digital COVID-19 Vaccine Record portal.

A person is still considered fully vaccinated when they have completed their original vaccine series (two shots of Moderna or Pfizer and one shot of J&J). Booster doses are not required to be considered fully vaccinated.