Find answers to frequently asked questions about the COVID-19 vaccines. Please check back often as information may change quickly.


Dr. Jennifer Veltman, chief of infectious diseases, answers common questions about COVID-19 vaccines.

Note: The information in this video may have changed since its filming in December 2020.

COVID-19 Vaccines: Now available to eligible individuals as supplies allow. Learn more.

Frequently Asked Questions

Getting Vaccinated

Is your hospital providing COVID-19 vaccines?

Yes, Loma Linda University Health is providing vaccinations based on national, state and county vaccine distribution guidelines. Vaccines are available for eligible individuals by appointment only as supplies allow — please view our vaccine page to check eligibility and appointment availability.

We expect to receive more vaccines in the near future. We’ll continue to offer vaccines to more groups over the coming months, according to state and national distribution guidelines. Please check our website often for updates on which priority groups are currently receiving vaccines at our facilities.

Can I get the vaccine sooner if I have special circumstances (serious medical condition, etc.)?

We're providing vaccines based on national, state and county vaccine distribution guidelines. The guidelines are designed to protect the most vulnerable people first — view county tier guidelines to see if you're currently eligible to receive a vaccine.

How will I get notified when I’m eligible to get a vaccine?

Check our website often for updates on which priority groups are currently receiving vaccines at our facilities.

Do I have to get more than one dose of the vaccine?

Yes, both vaccines require two doses. According to the CDC:

  • If you get the Pfizer/BioNTech vaccine, you'll need your second shot from 21 days to six weeks later.
  • If you get the Moderna vaccine, you'll need your second shot from 28 days to six weeks later.

What are the side effects and should I be worried if I have any?

Most people will have soreness around the vaccine injection site. While this can be quite painful, it should start to go away after about 24 hours. If you notice more pain or redness after 24 hours, contact your primary care physician.

Other common side effects include fatigue, muscle pain and headaches. These often show up within a few hours of getting the vaccine and can last for a few days. If these or any other side effects concern you or last longer than a few days, contact your primary care physician. According to the CDC, side effects are more common after the second dose. A small number of people have severe side effects that disrupt daily activities.

If you have any reaction after getting vaccinated, we recommend downloading the CDC’s v-safe app on your smartphone and reporting your symptoms. The CDC launched v-safe to help health experts monitor vaccine safety and respond to potential problems. V-safe will also remind you if you need a second dose of a vaccine.

If I get the vaccine, will it protect me from COVID-19? Will it protect others?

Yes, the vast majority of people (about 95%) will be protected from getting sick with COVID-19 after getting vaccinated. Experts believe the vaccines may also help keep you from getting seriously ill even if you do get COVID-19. 

After receiving your second vaccine dose, it takes your body about 10-14 days to develop immunity. However, you may still be able to transmit COVID-19 to other people. It’s still important to use a mask and practice social distancing after vaccination.

If I wait to get the vaccine, could it help someone else get it sooner?

In general, it won’t help someone more vulnerable than you. Vaccines distribution guidelines protect the most vulnerable groups first and preserve the functioning of society. If you’re in the current vaccine prioritization group, it’s not recommended to delay vaccination.

You may want to delay vaccination if you’ve recently tested positive for COVID-19, as reinfection is uncommon for at least 90 days afterward. You will still have the option of getting vaccinated when your group is eligible.

Who Should Get Vaccinated

Should I get the vaccine if I already had COVID-19?

Yes. It’s not yet understood how long your body’s natural immunity to COVID-19 lasts after fighting off the disease.

According to the CDC, you should wait 90 days to get a COVID-19 vaccine if you were treated with monoclonal antibodies or convalescent plasma. If you’re unsure if you received these treatments, talk to your doctor before getting vaccinated.

Should I get the vaccine if I’m immunocompromised or have HIV?

Little is known about the safety of the leading vaccines for people who have compromised immune systems or HIV. You may wish to receive the vaccine to prevent serious illness and should discuss your situation with a healthcare provider. If you choose to get vaccinated, you should continue to wear a mask, wash your hands frequently, and use other COVID-19 precautions.

If I have allergies, should I get a COVID-19 vaccine?

Before you get a COVID-19 vaccine, talk to your doctor if you have had a severe allergic reaction to other vaccines or injections. If you have any other specific concerns not covered below, please talk to your doctor before vaccination.

According to the CDC, you should not get one of the available mRNA COVID-19 vaccines if:

  • You’ve ever had a severe allergic reaction to any ingredient in that vaccine
  • You had a severe allergic reaction to the first dose of that vaccine
  • You had any allergic reaction (such as hives, swelling or wheezing) to either mRNA COVID-19 vaccine or any of their ingredients within four hours
  • You’re allergic to polyethylene glycol (PEG) or polysorbate

You can still get vaccinated if you have:

  • A history of severe allergic reactions not related to vaccine or injections
  • A history of allergies to oral medications
  • Family history of severe allergic reactions
  • Milder allergy to vaccines

Can pregnant women or kids get the vaccine?

There’s not yet enough data for a coronavirus vaccine to be approved for pregnant women or kids 15 and under. While the Pfizer/BioNTech vaccine is approved for use in individuals 16 years and older, the Moderna vaccine is only approved for use in individuals 18 and older.

Scientists are continuing to test vaccine safety for these groups and others. As is the case for other vaccines, FDA approval for these groups usually takes longer because research takes more time to complete.

Is the COVID-19 vaccine safe for pregnant women?

Clinical trials haven’t yet included pregnant or lactating individuals, so vaccine safety is unknown for these groups. The FDA, CDC and manufacturer are continuing to monitor safety in a few study participants who became pregnant shortly after receiving the vaccine.

What we do know is that COVID-19 can put both you and your baby at serious risk during pregnancy. Even if you don’t get seriously ill, the long-term effects of the virus on a fetus are still unknown. If all of the following apply to you, ask your doctor whether getting vaccinated is the right choice for you:

  • You’re pregnant or lactating
  • You live in an area where COVID-19 transmission is high
  • Your work puts you at increased risk of infection

Is my baby safe if I receive the COVID-19 vaccine?

We do not know for sure whether a vaccine will cause harm to a fetus, but it appears unlikely. 

The vaccine will very likely prevent you from getting sick from COVID-19, which could put both you and your fetus at serious risk. Even if you don’t have a severe form of the virus, we do not yet know the effects of the virus on pregnancies and fetuses as the pregnancy progresses after a COVID-19 infection. 

Because vaccines don’t contain any live virus, we do not believe they will cause harm to infants who are receiving breast milk. 

If all of the following apply to you, ask your doctor whether getting vaccinated is the right choice for you:

  • You’re pregnant or lactating
  • You live in an area where COVID-19 transmission is high
  • Your work puts you at increased risk of infection

About the Vaccines

Now that there’s a vaccine, can life return to normal?

A vaccine will not solve the pandemic until the vast majority of people get it, which may be possible in the second half of 2021. Until that time, COVID-19 remains a significant risk and it’s critical to continue safety measures like masking and social distancing.

How long will the vaccine protect me?

Right now, we can’t know if a coronavirus vaccine will be permanent or temporary. There simply hasn’t been enough time to test immunity in clinical trial volunteers over long periods of time. It is possible that regular booster shots will be necessary.

Are the COVID-19 vaccines tested enough to be safe?

Any vaccine goes through extremely rigorous testing both before and after it is offered to the public. Phase 3 trials (the final stage of testing) include tens of thousands of volunteers, half of which receive a vaccine. Most vaccine side effects are seen within the first six weeks after administration, therefore it is an encouraging sign that no major concerns have been noted following the end of enrollment in these large studies.

Safety has remained a priority even with the quick production of the coronavirus vaccines. Two factors that have sped up vaccine development include large amounts of government funding and ability to rapidly test volunteers during the pandemic.

The full range of side effects may take several years to discover. However, an approved vaccine will have a very small chance of serious side effects. COVID-19 infection presents much higher risk of serious complications.

Do the vaccines have risks?

There are no known serious, long-term risks from getting a COVID-19 vaccine. Scientists will continue to study the effects of vaccines in larger groups of people over longer periods of time. While there may still be unknown side effects, the data seems to show these would be rare.

What's in the coronavirus vaccines?

The Pfizer/BioNtech and Moderna vaccines use messenger RNA (mRNA) to teach your body to fight off COVID-19. The mRNA contains instructions to make a harmless piece of the "spike protein," which the coronavirus uses to attack the body. The vaccine does not contain live coronavirus and it can't alter your DNA.

Many vaccines also include substances that protect the vaccine from contamination, keep the vaccine working longer or were used to make the vaccine. None of these substances have ingredients in any amount that can be harmful to humans. The Pfizer/BioNtech and Moderna mRNA vaccines do not contain ethylmercury, formaldehyde or aluminum. No preservatives are used in the Pfizer/BioNtech and Moderna vaccines.

Do the vaccines work on COVID-19 variants?

There’s currently no evidence to suggest the COVID-19 vaccines will not work on variants of SARS-CoV-2.

Vaccine Myths

Can the vaccines infect me with COVID-19?

No. According to the CDC, none of the authorized and recommended COVID-19 vaccines or those in development in the U.S. contain the live virus. That means a vaccine can’t make you sick with COVID-19.

As the vaccine teaches your body how to recognize and fight the virus, you may experience symptoms like fever and fatigue. These don’t mean you have COVID-19 — they’re a normal part of vaccination (though some people don’t experience any side effects).

You may still contract COVID-19 after vaccination for two reasons:

  • Your body needs up to several weeks to gain immunity from the vaccine. During this time, you’re still vulnerable to infection.
  • The vaccines are about 94–95% effective, so immunity is very likely but not guaranteed.

Can the vaccines alter my DNA?

No. The COVID-19 vaccines never interact with DNA in any way.

Will the vaccines make me infertile?

According to the CDC, there is no evidence to suggest COVID-19 vaccines (or any vaccine) damage fertility in the short or long term. Experts believe any future risk is unlikely and scientists will continue to monitor and report vaccine side effects. It’s safe to get vaccinated no matter when you plan to become pregnant.

Recently, there have been unsubstantiated claims on social media that the COVID-19 vaccines can affect the development of the placenta. These claims have already been debunked by women’s health experts.