Answers to your questions

What is a vaccine?

Vaccines stimulate the body’s own protective immune responses so that, if a person is infected with a virus, the immune system is ready to prevent the infection from spreading within the body and causing disease.

What are the different types of COVID-19 vaccines and how do they work?

There are 3 primary types of COVID-19 vaccines:

-Protein-based vaccines

-mRNA vaccines

-Viral Vector Vaccines



What are COVID-19 vaccine side effects?
People often confuse reactogenicity (the physical signs that the immune system is working) with unexpected side effects of a vaccine. Reactogenicity includes all the signs and symptoms that you may feel between 1 or 2 days after getting vaccinated. Side effects are the things shouldn’t happen when you are exposed to a vaccine, like an allergic reaction.
Where can I get a COVID-19 Vaccine?

Find out where to get a COVID-19 vaccine with the Washington State Department of Health’s Vaccine Locator tool

How long will it take for the COVID-19 vaccine to start working?

Your body will begin building an immune response right away, but it can take time for your body to reach peak levels of antibodies after any vaccination. And with both the Pfizer and Moderna vaccines, you won’t get peak protection until after you get the 2nd shot three to four weeks after the first shot. While the Pfizer vaccine reported 95 percent efficacy in clinical trials, it didn’t reach that level until about a week after the second dose. At 10 days after the first shot, it was only about 52 percent effective.

Moderna’s results are similar. Clinical trial data show it reaches about 50% percent efficacy two weeks after the first dose. In the time before getting the second dose, vaccine efficacy climbs, but it’s not clear how long that would last without the 2nd dose, which is given four weeks after the first dose. Efficacy of two doses of the Moderna vaccine reached 94.1%.

If I had COVID-19, how much time should I wait before getting the vaccine?

People who have had COVID-19 are encouraged to get vaccinated when the vaccine becomes available to them as long as they have completed their quarantine period before going to get vaccinated, so the infection isn’t spread to those at the vaccine center.

If you were treated for COVID-19 symptoms with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.

Can I mix and Match COVID-19 vaccines?

No, you shouldn’t mix the vaccines because we don’t have data on the safety of doing that. Even though the Pfizer and Moderna vaccines rely on the same mRNA technology, they are still different products. After your first dose, you’ll receive a vaccination card indicating which vaccine you were given and the recommended date of the second dose. You’ll receive an information sheet telling you more about the vaccine, and you will also get information about the v-safe program to monitor your side effects after vaccination. To avoid delays, set up your second appointment at the same location where you got the first shot if you can. That way you’ll know you’ll get the same vaccine. If you start with the Pfizer vaccine, you should get the second dose of the Pfizer vaccine three weeks later. If you start with the Moderna vaccine, you should get the Moderna vaccine four weeks later.

Why not take my chances with COVID-19 rather than get a vaccine?

COVID-19 is by far the more dangerous option. COVID-19 vaccines carry little known risk. But the health impacts of COVID-19 have been well documented. About 20% of people who come down with COVID-19 symptoms develop serious, potentially life-threatening illness. Although people who are older, obese, or who have other health problems are at highest risk for complications from COVID-19, younger people can become severely ill, too. In a study of more than 3,000 people ages 18 to 34 who were hospitalized for COVID-19, 20% required intensive care and 3% died.

The long-term health complications associated with COVID-19 are another serious concern, and we’re learning more about them every day. As many as one in three people who recover from COVID-19 have chronic complaints for months afterward, including exhaustion, a racing heart, blood clots, and loss of sense of smell or taste. Many patients require extensive rehabilitation after being hospitalized for COVID-19.

Should you get a COVID-19 test just prior to getting the vaccine?

Yes, you will likely still get the second shot as scheduled, but check with the vaccine distribution center to confirm. If you have COVID-19 symptoms, you should quarantine to ensure that you do not transmit illness to others.

Consult your provider for advice on whether or not you should take the COVID-19 vaccine if you have any questions or concerns.

Should I get the COVID-19 vaccine if I have pre-existing health conditions?

People with other medical conditions, taking medications, and even a history of allergies can probably get a COVID-19 vaccine. But since not every health condition or every person is the same, you should get specific advice from a healthcare provider who knows your particular health circumstances. Consult your provider for advice on whether or not you should take the COVID-19 vaccine if you have any questions or concerns.

Can I take medication (Aspirin, Tylenol, Aleve etc.) prior to my vaccination to help with mild side effects?

No. Do not take meds before getting the shot. You should only be taking Tylenol or ibuprofen to treat actual symptoms if they occur.

Why do I have to wait 15-30 minutes after my vaccine shot?

Everyone who gets the vaccine will be asked to stick around for about 15 minutes after getting the shot. This will allow health workers to monitor you for any signs of an allergic reaction, which are rare.

A person with a history of severe allergies may be asked to stay for 30 minutes.

Remember when you first receive the vaccine that you won’t be fully protected until about a week after the final dose.

Can you delay your second dose of the COVID-19 vaccine longer than the suggested 3-4 weeks?

We know that having some time between shots is ideal – your body needs time to build the immune response. While a delay for a bit is fine (in case there are scheduling issues), it is still optimal to get the second dose 3 or 4 weeks later as recommended.

What are the common side effects people are having from COVID-19 vaccines?

The side effects that people sometimes experience after taking the COVID-19 shot are a sore arm, low fever, muscle and joint aches, headaches and feeling tired. These are indication that your body is responding to the vaccine just the way we want it to!

It’a working to build a response to COVID-19 so that if you are ever exposed your body will be able to fight back. Most people find that they can take some acetaminophen or ibuprofen, rest and the side effects typically go away within a day or two.

Why are so many people experiencing more side effects with the second COVID-19 vaccine shot, but not the first? This is a reflection of your body reacting to the vaccine. The two shots are the same: the first shot is alerting your immune system, but the second shot is following up and really boosting that response.

Talk to your doctor if you experience any other side effects after getting a COVID-19 vaccine.

If I get a COVID-19 vaccine, can I stop wearing a mask?

Not yet. The vaccines are good news for protecting people from disease but we don’t yet know if the vaccines will stop people from getting infected or being able to spread coronavirus. Masks are still needed as the best way to stop spreading the virus.

Why are we still studying COVID-19 vaccines?

Although science and study volunteers gave us vaccines that are authorized for public use, we cannot stop our search for effective and safe vaccines. The more vaccines there are, the quicker we can protect everyone who wants to receive one.

Reduce severity of COVID-19Several COVID-19 VaccinesPeople WorldwideQuestions about COVID-19

Were transplant recipients included in the COVID-19 vaccine trials?

Transplant patients were not included in the vaccine trials. Despite the lack of information, transplant advocacy groups have urged patients to get the Pfizer or Moderna COVID-19 vaccines.

Transplant patients, who must take drugs that suppress their immune systems, are at high risk for complications if they contract COVID-19. Research shows transplant patients with COVID-19 have a 30% increased risk of dying than patients with no underlying risk factors.

Although the mRNA vaccines haven’t been studied in transplant patients, doctors know that vaccines that do not involve giving a transplant patient a live virus are generally safe. The Pfizer and Moderna vaccines use messenger RNA molecules to stimulate the immune system and do not contain any form of live, dead or neutralized virus.

The American Society of Transplantation created a fact sheet for transplant patients, and advises patients who get vaccinated to continue to wear a mask and take precautions to avoid being exposed to the Coronavirus.

Do we know if COVID-19 vaccines will be safe for people with HIV?

Trials studying the various COVID-19 vaccines have included people living with HIV, but the numbers were small. The Pfizer trial included 120 people with HIV, and the Moderna trial included 176 people with HIV.

Although the numbers are too small to draw meaningful conclusions, no unusual safety concerns were reported for people living with HIV. People with undetectable viral loads who are taking antiretroviral therapy are not usually considered “immunocompromised.”

Because the Pfizer and Moderna vaccines do not contain live, weakened or inactivated coronavirus, they are believed to be a safe option for people living with HIV and AIDS.

If you have more questions about getting a COVID-19 vaccine, please talk to your healthcare provider for a recommendation based on your specific health history.

Are the claims about COVID-19 vaccines affecting fertility true?

A false claim has been circulating online that the new COVID-19 vaccines will threaten a person’s fertility by harming the placenta. Here’s why it’s not true.

The claim stems from the fact that the vaccines from Pfizer and Moderna cause our immune systems to make antibodies to something called the “spike protein” on the coronavirus. The false claim about fertility risk is based on the unfounded concern that these antibodies could also attack another protein that is made in the placenta during pregnancy, called syncytin. In reality, the spike protein and syncytin are similar only in one very small region, and there’s no evidence that antibodies that can grab onto the coronavirus spike proteins would also lock onto syncytin.

What’s more, the human body generates its own supply of spike antibodies when it fights off the coronavirus, and there’s been no sign that these naturally occurring antibodies attack the placenta in pregnant people who become sick with COVID-19. If they did, you’d expect that people who got COVID-19 would have a higher rate of miscarriages. But a number of studies have shown that COVID-19 does not trigger miscarriages.

If you feel that you have a low risk of being exposed to coronavirus, then it may make sense to wait to vaccinate until the baby is born or until more data are available. If you have more questions about getting a COVID-19 vaccine or the impact of vaccines on fertility or pregnancy, please talk to your healthcare provider for a recommendation based on your specific health history.

What’s the difference between coronavirus, SARS-CoV-2, and COVID-19?

The novel coronavirus responsible for this outbreak is known as SARS-CoV-2. The illness caused by the virus is called COVID-19.

Why is it called a coronavirus? Coronaviruses are named after the Latin word corona, meaning “crown” or “halo,” because they have “crown-like spikes on their surface,” according to the U.S. Center for Disease Control and Prevention.

How are coronaviruses transmitted between people?

Coronaviruses are typically transmitted from person to person through respiratory droplets exhaled from the nose and mouth and being in close contact. People can get the infection if they breathe in droplets from an infected person who coughs or exhales droplets. Small droplets that contain infectious amounts of virus can also remain suspended in the air for a period of time and travel farther distances than larger droplets that are usually produced when people sneeze or cough.

Wearing a mask, staying at least six feet away from others, and avoiding extended contact (for more than fifteen minutes) indoors with other people are all helpful ways to reduce being exposed to the virus.

Can a COVID-19 vaccine create population immunity (herd immunity)?

We don’t know yet.
Studies show that the vaccines prevent severe COVID-19 disease, but we need more time to find out if they also prevent infection with or transmission of coronavirus.
How Population immunity works with other vaccines that prevent infection:
-Not Immunized, but still healthy
-Immunized and healthy
-Not immunized, sick, and contagious
If no one is immunized, contagious disease spreads through the population.

If some of the population gets immunized, contagious disease spreads through the unvaccinated population.

If most of the population gets immunized, the virus has nowhere to go and can’t spread to people who can’t get immunized (babies, people who are immunocompromised) because they are protected by immunized people around them.

Why is a COVID-19 vaccine different?

The studies have shown the COVID-19 vaccines are effective at preventing severe disease.
This is important for the vaccinated people and their communities. It means people don’t need so much time away from work or their families, and it means that the burden on hospitals and healthcare system is reduced.

We don’t know yet if COVID-19 vaccines also prevent infection or prevent transmitting the virus to others, if people who are vaccinated can still get infected and transmit the virus to others it will be harder to achieve population immunity.

We need the research to continue to help us find this answer.

What is the current status of COVID-19 vaccine research in children and adolescents?

To date, Pfizer has enrolled children down to age 12 and its EUA (Emergency Use Authorization) for vaccination down to age 16 was recently approved. Moderna is about to start a similar study, as is Janssen. AstraZeneca has approval to enroll children in the UK, ages 5-12, but has not yet enrolled any children in the US. We anticipate that studies including younger children will begin soon.

Is there data from volunteers who got pregnant or who were breastfeeding during COVID-19 vaccines studies?

Are there any data from volunteers who got pregnant or who were breastfeeding during COVID-19 vaccines studies?

No pregnancy related data have been released yet. Typically in large studies there are some unexpected pregnancies, even though participants able to become pregnant were counseled about using contraception. Pregnancy and breastfeeding are not considered contraindications to receiving an approved COVID-19 vaccine, however, there is no substantial safety data in pregnant people, the fetuses, or infants at this time.

Are there any negative effects of COVID-19 vaccines on pregnancy, the developing fetus, or infants?

Are there any effects of COVID-19 vaccines on pregnancy, the developing fetus, or infants? 

While these approved COVID-19 vaccines were not specifically tested in breastfeeding people, it is not likely that there would be any risk to the child because of how these vaccines in the US studies work. People who are pregnant or who may become pregnant around the time of vaccination, and people who are breastfeeding, will be able to choose whether they want to receive a COVID-19 vaccine that is currently available under Emergency Use Authorization when it becomes available to them.