How do we know the vaccines are safe? Should I worry that the vaccine was made so quickly?

Reviewed Nov. 29, 2022 The COVID-19 vaccines now available are based on science that’s been studied for decades. These vaccines were produced quickly in part thanks to strong funding for clinical trials by multiple governments, as well as private organizations. Enrollment was faster than usual because the public was motivated to volunteer. Trials reached their endpoints quickly because of the high levels of COVID-19 disease throughout the world, which made it easy to see a difference between vaccinated and unvaccinated groups. None of the necessary scientific steps were skipped. In addition, both vaccines were found to be safe and effective in tens of thousands of adults who participated in double-blind, placebo-controlled clinical trials – widely considered the gold standard for testing drug safety and effectiveness. In this type of trial, researchers and participants do not know which participants are receiving the real drug and which are receiving the placebo (a substance that looks like the real drug but has no direct effects on the body). Because neither group knows who got what, it’s less likely for human error or bias to affect the results.

Am I protected as soon as I'm vaccinated? Can I stop wearing a mask and physically distancing?

Reviewed February 25, 2021 No. The Pfizer and Moderna vaccines do not provide full protection against COVID-19 until at least a week after the second dose. However, because the coronavirus will remain a threat to public health for many months, and because no vaccine is 100 percent effective, you should continue to follow all public health guidance related to COVID-19, including wearing a mask, physically distancing, frequent hand-washing, and avoiding all nonessential travel and gatherings.

I got the first dose of the COVID-19 vaccine somewhere else. Can I schedule the second dose with UCSF?

Reviewed March 24, 2021 No, you should return to the center that dispensed the first dose to make sure you receive the correct second dose. In unusual situations in which this is not possible (e.g., for new employees who got their first dose out-of-state), UCSF will try to accommodate the request.

Is there a charge for the COVID-19 vaccine? Will it be covered by insurance such as Medicare and Medi-Cal?

Reviewed February 25, 2021 Public health departments are distributing COVID-19 vaccines for free because the government has purchased millions of doses. In the future, this may change. The government may purchase more doses, your insurance may cover the cost, or you may be able to pay out of pocket.

Do you have any information about the vaccine that I can read before getting mine?

Reviewed February 25, 2021 We have provided a patient-education FAQ to all of our employees and patients before they sign up for their vaccine. It contains many answers to questions about the vaccines that are currently available and what to expect during and after your vaccination.

What is the update, bivalent COVID-19 booster?

Reviewed November 2022 The bivalent COVID-19 booster vaccine is designed to protect against the newer COVID-19 variants that are currently making people sick. UCSF doctors recommend this safe and effective booster shot.

Who is eligible for the bivalent COVID-19 booster?

Reviewed November 2022 Anyone who’s at least 5 years old is eligible for the updated booster. Please note that you shouldn’t get the updated booster too soon after your last Pfizer or Moderna shot or a recent COVID infection – even if you tested positive but didn’t get sick. You should wait two months after your last shot and three months after a COVID infection. Also, if you’ve never had a COVID-19 vaccine, you’ll need to get the primary series vaccines first. Then you can get the updated booster. People with weak immune systems are more likely to get very ill from COVID. They may need both the updated booster and other protection. People with weak immune systems are more likely to get very ill from COVID. They may need both the updated booster and other protection. You can read more about at the CDC website . For information on vaccinating children under 5, see the UCSF pediatric COVID-19 vaccine page .

Why should I get the updated booster?

Reviewed November 2022 To understand the importance of getting this booster, consider the following: Scientists have learned that the COVID vaccines we took months ago get less effective over time. The updated booster gives us a burst of immunity to fight the old and new forms of the virus. This is how we can protect ourselves, our loved ones and our community from COVID-19. The updated booster can keep us from catching COVID-19. And if we do get infected, this booster can prevent severe disease and keep us out of the hospital. It is especially important for older adults (age 65+) and people with compromised immune systems to get the updated booster. The COVID-19 virus is always changing (making new variants). That’s what viruses do. So we need the updated booster shots for protection against the new variants.

I've had COVID-19. Should I still get the updated booster?

Reviewed November 2022 Yes. A person can be infected by the COVID-19 virus more than once. Getting the updated COVID-19 booster after having COVID-19 provides your immune system with more protection .

Can I get a COVID-19 booster vaccine and flu vaccine at the same time?

Reviewed November 2022 Yes. All COVID-19 vaccines and the new booster are safe and effective when given with other vaccines. At UCSF, you can get the flu vaccine at the same time as a COVID-19 vaccine or booster. To get both shots at the same appointment, schedule an appointment for your COVID vaccine or updated booster; then, when you arrive for your appointment, ask to get the flu shot.

Should I get a COVID-19 vaccine?

Reviewed February 25, 2021 Yes, most people should be vaccinated as soon as they are eligible and have access. In addition to reducing your chances of contracting COVID-19, the vaccines have been very effective at preventing severe illness and death in those who do develop it. Vaccination also helps prevent the chronic health effects that have been reported in some patients long after they recover from the acute stage of the illness. Exceptions: Patients with a recent or upcoming organ or stem cell transplantation, and those receiving strong immunosuppressive medications, may want to postpone getting the COVID-19 vaccine for a short time. Similarly, patients who have recently recovered from COVID-19 disease may want to postpone being vaccinated, especially if they received certain medical therapies during their illness. Patients in these situations should speak to their medical team about the best timing for vaccination.

Which updated booster shot should I get: Moderna or Pfizer?

Reviewed November 2022 You can choose either. Both work well. You don’t need to get the same kind you had in the past. For information about the updated booster for children, see our pediatric COVID-19 vaccine page .

Do I still need to get a flu vaccine if I received the updated COVID-19 booster?

Reviewed November 2022 Yes. The flu vaccine targets the flu virus, and the COVID-19 vaccines target the COVID-19 virus and its variants. COVID vaccines don’t protect you from the flu.

How can I get a flu shot?

Learn how to schedule a flu shot at one of our UCSF flu clinics.

I have a history of allergies. What should I do?

Reviewed February 25, 2021 If you have a history of allergies, check the risk assessment categories below to see whether you might need to visit your doctor for further evaluation. If any of the following have happened to you after receiving a vaccine or medication, you could be at risk for an allergic reaction: hives or rash, swelling of a body part, wheezing or shortness of breath, repeated vomiting or diarrhea, low blood pressure, treatment with epinephrine, intubation or hospitalization. Low risk I have an allergy to food, animals, stinging insect venom (bee, wasp, hornet), pollens, latex and/or oral medications. I had a reaction to a vaccine or injectable medication that was NOT an allergic reaction or anaphylaxis. You should be observed for 30 minutes after being vaccinated. Medium risk I had a reaction to a vaccine or injectable medication that could be an allergic reaction or anaphylaxis. I had a reaction to the first dose of the COVID-19 vaccine that was NOT anaphylaxis. Discuss with your health care provider whether it’s safe for you to be vaccinated. Your provider can place an e-consult to Allergy at UCSF to determine the need for evaluation or testing. High risk I had a reaction to the first dose of the COVID-19 vaccine that could be an allergic reaction or anaphylaxis. Ask your health care provider to refer you to Allergy at UCSF for possible allergy testing.

I had an allergic reaction to a vaccine in the past. What should I do?

Reviewed February 25, 2021 If you’ve had a previous allergic reaction to a vaccine, your doctor may need to evaluate you.

I already had COVID-19. Do I still need the vaccine? When is the right time?

Reviewed January 19, 2022 Yes. The CDC recommends that people who have had COVID-19 get vaccinated after their symptoms resolve and their isolation period ends. The same guidance applies to booster shots.

How will I know when I am eligible for the vaccine? Should I ask my doctor?

Reviewed March 24, 2021 UCSF is following state guidelines for its vaccine rollout to ensure that we distribute vaccines to people based on their risk. You can sign up at MyTurn before you're eligible to be vaccinated, and they will notify you when you become eligible. Once you're eligible, you can make your appointment directly through MyTurn. You can also visit your county's vaccine website to make an appointment at county-run vaccination clinics and major pharmacy chains, such as Walgreens, CVS and Safeway. Please do not ask your doctor about vaccine scheduling. Because we are following state guidelines, your doctor will not be able to schedule your vaccine or influence when you receive it.

Is there a charge for the COVID-19 vaccine? Will it be covered by insurance such as Medicare and Medi-Cal?

Reviewed February 25, 2021 Public health departments are distributing COVID-19 vaccines for free because the government has purchased millions of doses. In the future, this may change. The government may purchase more doses, your insurance may cover the cost, or you may be able to pay out of pocket.

COVID-19 Vaccines at UCSF Health

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Updated Nov. 29, 2022

Note: UCSF is now offering updated COVID-19 boosters to anyone who’s at least 5 years old. You don’t have to be a UCSF patient. The new boosters provide improved protection against the most common variants of COVID-19 making people sick today. UCSF doctors are recommending this safe and effective updated shot. (If you recently had a COVID vaccine of any type, you need to wait two months before getting the updated booster.) Schedule an appointment now through MyChart or by calling (415) 476-3307.

COVID-19 vaccines remain the best public health measure to protect people from the virus, slow transmission and reduce the likelihood of new variants emerging.

UCSF Health offers COVID-19 vaccines to anyone who is eligible, not just UCSF patients. If you're seeking a booster shot, see information about eligibility below.

Who's eligible for the COVID-19 vaccine

Everyone who's at least 6 months old is eligible for a COVID-19 vaccine. Learn more about COVID-19 vaccines for kids at UCSF Benioff Children's Hospitals.

Where to get the COVID-19 vaccine

Pfizer, Moderna and Novavax COVID-19 vaccines require two doses and two appointments. When you get your first dose, we'll schedule your second. (Pfizer and Moderna are preferred in most situations.)

Anyone who is eligible can get a vaccine at UCSF's Laurel Heights and Mission Bay clinics. You do not need to be a UCSF patient.

Laurel Heights campus (ages 6 months+; general public)
3333 California St.
San Francisco, CA 94418
Hours: M-F, 8 a.m. - 4 p.m. (closed noon - 1 p.m.)
We strongly recommend making an appointment. Schedule through MyChart or by calling (415) 476-3307.

Mission Bay campus (ages 6 months+; general public)
601 16th St. (corner of 16th and Owens streets)
San Francisco, CA 94158
Hours: Mondays and Fridays, 7:30 a.m. - 7 p.m. | Wednesdays, 8 a.m. - 4 p.m. (closed noon - 1 p.m. all days)
We strongly recommend making an appointment. Schedule through MyChart or by calling (415) 476-3307.

For some patients, it may be quicker to get the vaccine at their local pharmacy or vaccination clinic. To schedule an appointment, visit your pharmacy's website, your county's vaccine website, California's My Turn, or the national Vaccines.gov site.

More information about vaccine appointments for kids

COVID-19 booster shots

U.S. health officials have approved COVID-19 booster shots for all adult recipients of the Pfizer, Moderna and Johnson & Johnson vaccines. The latest boosters, known as bivalent boosters, are designed to target COVID-19's Omicron subvariants better than the original monovalent boosters, which are no longer offered. To learn more, read our FAQs about the updated boosters.

All adults should get this updated booster at least two months after their most recent shot, whether that was the second dose of a primary series or a monovalent booster.

(For information about booster eligibility for children, see our pediatric COVID-19 vaccine page.)

You can receive your booster at one of the UCSF vaccination sites listed above, and you may choose either Pfizer or Moderna for this booster, regardless of which vaccine you initially received.

To select a particular booster, schedule an appointment through MyChart or by calling (415) 476-3307. Vaccine inventory can vary, and we can't guarantee we'll have the booster you want if you walk in without an appointment.

You can also schedule booster shots with some primary care physicians or at a local pharmacy.

Johnson & Johnson eligibility

If you received the Johnson & Johnson single-dose vaccine, you should get an updated Moderna or Pfizer booster at least two months after your most recent shot, whether that was a single dose of J&J or a monovalent booster.

Moderna and Pfizer eligibility

If you received Moderna or Pfizer, you should get an updated booster at least two months after your most recent shot, whether that was the second dose of a primary series or a monovalent booster.

The purpose of an updated booster shot – which helps maximize and extend the protection that the COVID-19 vaccine provides and strengthen protection against the Omicron subvariants – is different from an "additional dose" of the vaccine, which was approved in August 2021 for immunocompromised patients. (If you're immunocompromised, find out about eligibility for additional shots of either Pfizer or Moderna in the next section.)

Additional doses for immunocompromised patients

Moderately to severely immunocompromised patients who received the Pfizer or Moderna vaccine should get three vaccine doses and an updated booster (four shots in total), according to the Centers for Disease Control and Prevention (CDC). The third dose can provide additional protection to those whose immune system didn't fully respond to the initial two doses.

The CDC recommends an additional dose and updated booster of an mRNA vaccine (Pfizer or Moderna) for patients who received the Johnson & Johnson vaccine. See details about the recommended doses and timeline for your situation.

All immunocompromised adults should receive an updated booster two months after their most recent vaccine dose or monovalent booster. For patients who followed the CDC's prior booster guidelines, this updated booster could be their fifth or sixth shot.

UCSF Health is offering third doses and boosters to eligible patients. See above for our locations, plus where to book an appointment for a shot in your community. UCSF Benioff Children's Hospital Oakland also offers additional doses for immunocompromised patients at the hospital's Outpatient Center.

Eligibility

You're considered immunocompromised and eligible for a third dose if you:

Are receiving treatment for tumors or blood cancer
Have received an organ transplant and are taking medication to suppress your immune system
Have received a stem cell transplant within the last two years or are taking medicine to suppress your immune system
Have a condition that moderately or severely impairs immune function
Have advanced or untreated HIV infection
Are taking high-dose corticosteroids or other medications that suppress immune function

Guidelines for immunocompromised patients

If you received a two-dose Pfizer or Moderna vaccine series you should get:

A third vaccine dose of Pfizer or Moderna more than one month after your second dose.
An updated booster shot of Pfizer or Moderna at least two months after your third vaccine dose or most recent monovalent booster.

You can mix and match Pfizer and Moderna vaccines or continue with the same manufacturer.

If you received the one-dose Johnson & Johnson vaccine, you should get:

A second vaccine dose of Pfizer or Moderna at least one month after your Johnson & Johnson vaccine
An updated booster shot of Pfizer or Moderna at least two months after your second vaccine dose or most recent monovalent booster.

If you followed the CDC's previous booster guidelines for immunocompromised patients, this updated booster dose could be your fifth or sixth shot.

Free MUNI rides in San Francisco

The San Francisco public transit agency is providing free MUNI and paratransit rides to and from COVID-19 vaccine appointments. The offer is good for trips to any vaccination site. You'll have to show your vaccination card or proof of your appointment (such as an email or text confirmation) when you board.

Public health recommendations for fully vaccinated people

See the latest COVID-19 recommendations from the CDC. Learn about your risks when it comes to socializing with vaccinated or unvaccinated people, other social activities outside the home, domestic and international travel, and more.

FAQs: Understanding the COVID-19 vaccine

How do we know the vaccines are safe? Should I worry that the vaccine was made so quickly?
Reviewed Nov. 29, 2022

The COVID-19 vaccines now available are based on science that’s been studied for decades. These vaccines were produced quickly in part thanks to strong funding for clinical trials by multiple governments, as well as private organizations. Enrollment was faster than usual because the public was motivated to volunteer. Trials reached their endpoints quickly because of the high levels of COVID-19 disease throughout the world, which made it easy to see a difference between vaccinated and unvaccinated groups. None of the necessary scientific steps were skipped. In addition, both vaccines were found to be safe and effective in tens of thousands of adults who participated in double-blind, placebo-controlled clinical trials – widely considered the gold standard for testing drug safety and effectiveness. In this type of trial, researchers and participants do not know which participants are receiving the real drug and which are receiving the placebo (a substance that looks like the real drug but has no direct effects on the body). Because neither group knows who got what, it’s less likely for human error or bias to affect the results.
Should I get a COVID-19 vaccine?
Reviewed February 25, 2021

Yes, most people should be vaccinated as soon as they are eligible and have access. In addition to reducing your chances of contracting COVID-19, the vaccines have been very effective at preventing severe illness and death in those who do develop it. Vaccination also helps prevent the chronic health effects that have been reported in some patients long after they recover from the acute stage of the illness.

Exceptions: Patients with a recent or upcoming organ or stem cell transplantation, and those receiving strong immunosuppressive medications, may want to postpone getting the COVID-19 vaccine for a short time. Similarly, patients who have recently recovered from COVID-19 disease may want to postpone being vaccinated, especially if they received certain medical therapies during their illness. Patients in these situations should speak to their medical team about the best timing for vaccination.
I have a history of allergies. What should I do?
Reviewed February 25, 2021

If you have a history of allergies, check the risk assessment categories below to see whether you might need to visit your doctor for further evaluation.

If any of the following have happened to you after receiving a vaccine or medication, you could be at risk for an allergic reaction: hives or rash, swelling of a body part, wheezing or shortness of breath, repeated vomiting or diarrhea, low blood pressure, treatment with epinephrine, intubation or hospitalization.

Low risk
- I have an allergy to food, animals, stinging insect venom (bee, wasp, hornet), pollens, latex and/or oral medications.
- I had a reaction to a vaccine or injectable medication that was NOT an allergic reaction or anaphylaxis.
You should be observed for 30 minutes after being vaccinated.

Medium risk
- I had a reaction to a vaccine or injectable medication that could be an allergic reaction or anaphylaxis.
- I had a reaction to the first dose of the COVID-19 vaccine that was NOT anaphylaxis.
Discuss with your health care provider whether it’s safe for you to be vaccinated. Your provider can place an e-consult to Allergy at UCSF to determine the need for evaluation or testing.

High risk
- I had a reaction to the first dose of the COVID-19 vaccine that could be an allergic reaction or anaphylaxis.
Ask your health care provider to refer you to Allergy at UCSF for possible allergy testing.
I had an allergic reaction to a vaccine in the past. What should I do?
Reviewed February 25, 2021

If you’ve had a previous allergic reaction to a vaccine, your doctor may need to evaluate you.
I already had COVID-19. Do I still need the vaccine? When is the right time?
Reviewed January 19, 2022

Yes. The CDC recommends that people who have had COVID-19 get vaccinated after their symptoms resolve and their isolation period ends. The same guidance applies to booster shots.

FAQs: Getting the COVID-19 vaccine

Do you have any information about the vaccine that I can read before getting mine?
Reviewed February 25, 2021

We have provided a patient-education FAQ to all of our employees and patients before they sign up for their vaccine. It contains many answers to questions about the vaccines that are currently available and what to expect during and after your vaccination.
Is there a charge for the COVID-19 vaccine? Will it be covered by insurance such as Medicare and Medi-Cal?
Reviewed February 25, 2021

Public health departments are distributing COVID-19 vaccines for free because the government has purchased millions of doses. In the future, this may change. The government may purchase more doses, your insurance may cover the cost, or you may be able to pay out of pocket.
Am I protected as soon as I'm vaccinated? Can I stop wearing a mask and physically distancing?
Reviewed February 25, 2021

No. The Pfizer and Moderna vaccines do not provide full protection against COVID-19 until at least a week after the second dose. However, because the coronavirus will remain a threat to public health for many months, and because no vaccine is 100 percent effective, you should continue to follow all public health guidance related to COVID-19, including wearing a mask, physically distancing, frequent hand-washing, and avoiding all nonessential travel and gatherings.
I got the first dose of the COVID-19 vaccine somewhere else. Can I schedule the second dose with UCSF?
Reviewed March 24, 2021

No, you should return to the center that dispensed the first dose to make sure you receive the correct second dose. In unusual situations in which this is not possible (e.g., for new employees who got their first dose out-of-state), UCSF will try to accommodate the request.

FAQs: About update (bivalent) COVID-19 boosters

What is the update, bivalent COVID-19 booster?
Reviewed November 2022

The bivalent COVID-19 booster vaccine is designed to protect against the newer COVID-19 variants that are currently making people sick. UCSF doctors recommend this safe and effective booster shot.
Who is eligible for the bivalent COVID-19 booster?
Reviewed November 2022

Anyone who’s at least 5 years old is eligible for the updated booster.

Please note that you shouldn’t get the updated booster too soon after your last Pfizer or Moderna shot or a recent COVID infection – even if you tested positive but didn’t get sick. You should wait two months after your last shot and three months after a COVID infection. Also, if you’ve never had a COVID-19 vaccine, you’ll need to get the primary series vaccines first. Then you can get the updated booster. People with weak immune systems are more likely to get very ill from COVID. They may need both the updated booster and other protection.

People with weak immune systems are more likely to get very ill from COVID. They may need both the updated booster and other protection. You can read more about at the CDC website.

For information on vaccinating children under 5, see the UCSF pediatric COVID-19 vaccine page.
Why should I get the updated booster?
Reviewed November 2022

To understand the importance of getting this booster, consider the following:
1. Scientists have learned that the COVID vaccines we took months ago get less effective over time. The updated booster gives us a burst of immunity to fight the old and new forms of the virus. This is how we can protect ourselves, our loved ones and our community from COVID-19.
2. The updated booster can keep us from catching COVID-19. And if we do get infected, this booster can prevent severe disease and keep us out of the hospital.
3. It is especially important for older adults (age 65+) and people with compromised immune systems to get the updated booster.
4. The COVID-19 virus is always changing (making new variants). That’s what viruses do. So we need the updated booster shots for protection against the new variants.
I've had COVID-19. Should I still get the updated booster?
Reviewed November 2022

Yes. A person can be infected by the COVID-19 virus more than once. Getting the updated COVID-19 booster after having COVID-19 provides your immune system with more protection.
Can I get a COVID-19 booster vaccine and flu vaccine at the same time?
Reviewed November 2022

Yes. All COVID-19 vaccines and the new booster are safe and effective when given with other vaccines.

At UCSF, you can get the flu vaccine at the same time as a COVID-19 vaccine or booster. To get both shots at the same appointment, schedule an appointment for your COVID vaccine or updated booster; then, when you arrive for your appointment, ask to get the flu shot.
Which updated booster shot should I get: Moderna or Pfizer?
Reviewed November 2022

You can choose either. Both work well. You don’t need to get the same kind you had in the past.

For information about the updated booster for children, see our pediatric COVID-19 vaccine page.
Do I still need to get a flu vaccine if I received the updated COVID-19 booster?
Reviewed November 2022

Yes. The flu vaccine targets the flu virus, and the COVID-19 vaccines target the COVID-19 virus and its variants. COVID vaccines don’t protect you from the flu.
How can I get a flu shot?
Learn how to schedule a flu shot at one of our UCSF flu clinics.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.