COVID-19 Vaccine Frequently Asked Questions

We know our patients have questions about COVID-19 vaccines. Find answers here.

COVID-19 Vaccine FAQs

Who can get vaccinated?

The Massachusetts Department of Public Health recommends that everyone ages 6 months and older receive a COVID-19 primary series vaccination for the prevention of COVID-19.

Everyone ages 5 years and older should receive at least 1 booster dose of COVID-19 vaccine, if eligible. Eligibility for booster dose(s) varies based on age, COVID-19 vaccine product, immunocompetence and other factors. Ask your provider for more information.

Where can I get vaccinated?

There are a number of places to get vaccinated. Visit our How to Get Vaccinated page to learn more.

Can I be vaccinated at home?

In-home vaccinations are available for anyone in Massachusetts who is unable to get to a vaccine location. Visit the state’s website for more information.

I’m scheduled to receive another vaccine soon. Do I need to wait before receiving my COVID-19 vaccine?

No, you do not need to wait before receiving other vaccines (for example, a flu vaccine). If you have questions about when to schedule your vaccination, please contact your healthcare provider.

Is it safe to take pain relievers before vaccination?

If you regularly take aspirin, acetaminophen (e.g. Tylenol), or ibuprofen (e.g. Motrin, Advil) for other medical conditions, continue to do so as directed by your doctor. Otherwise, do not take them before vaccination. Taking these over-the-counter pain relievers before receiving a vaccine may reduce its ability to work and slow your immune system’s response to it.

How many doses of vaccine will I need? Should I always get the same type?

The number of doses you need will depend on the type of vaccine you receive and your personal circumstances. In most situations, the use of an mRNA vaccine (Pfizer or Moderna) is preferred.

Vaccination guidelines change frequently. Please check the CDC’s website for the most recent information and guidance.

I have a condition associated with a weakened immune system. Should I get vaccinated against COVID-19?

All of the vaccines that are currently available are safe for people with compromised immune systems, and none of the currently available COVID-19 vaccines contain live virus. Most patients with weakened immune systems can be vaccinated safely. Your healthcare provider can help answer questions about your personal situation.

How do I get proof of my COVID-19 vaccination?

The state of Massachusetts offers a digital vaccine card to people who were vaccinated in the state. For information or to access your record, visit the state’s website.

Alternatively, if you were vaccinated at a Beth Israel Lahey Health site, you can request written confirmation of your COVID-19 vaccination as part of your medical record. Locate your vaccination site here, and follow the directions to request your vaccination documentation.

Do I need another COVID-19 shot?

Your initial vaccination series provides protection against COVID-19 but we recommend that you stay up to date with the recommended vaccine doses for you based on your health conditions. For the most recent guidance, visit the CDC’s website.

What is a booster shot?

A COVID-19 booster shot is given several months after the initial vaccine due to concerns the vaccine’s effectiveness could decrease over time and our knowledge that a booster shot strengthens your immune response against COVID-19 and its variants.

Does my COVID-19 booster have to be the same brand as my initial series?

No. The CDC has recommended that people who are eligible to receive a COVID-19 booster shot can choose which brand vaccine they’d like to receive. You may choose to receive the same vaccine you received before, or select a different brand for your booster shot. However, mRNA vaccines (Pfizer-BioNTech or Moderna) are preferred in most situations.

More Information

For more information, visit the CDC’s list of FAQs.

Are COVID-19 vaccines approved by the FDA for all ages?

The Pfizer-BioNTech vaccine is fully approved by the U.S. Food and Drug Administration (FDA) for use in individuals 16 years and older. It is available under Emergency Use Authorization (EUA) for people aged 6 months-15 years.

The Moderna vaccine is FDA-approved for individuals 18 years and older. It is available under EUA for people aged 6 months-17 years.

The Novavax vaccine is available under EUA for adults aged 18 and over. It is a more traditional protein-based vaccine not utilizing mRNA. It is not yet approved for younger age groups or as a booster.

The Johnson & Johnson vaccine is available on a more restricted basis—ask your provider.

Where can I get my kids vaccinated?

You can visit the Massachusetts online directory to view hundreds of vaccination sites and search for locations or reach out to your child’s pediatrician directly.

Are the vaccines safe?

Over 10 billion doses of COVID-19 vaccines have been administered all over the world. These have proven safe and effective.

The vaccines are considered safe and effective for children, but may cause achiness and/or a sore arm. The doses provided to children are adjusted to reduce side effects while maintaining effectiveness. Ask your provider for more information.

What reactions can I expect after the COVID-19 vaccine?

Reactions following COVID vaccination are similar to those after other vaccinations like a flu shot or a shingles vaccine, including fever, chills, headache, fatigue, joint and muscle aches, as well as pain at the injection site. After COVID vaccination for Moderna and Pfizer 80-92% of persons will develop at least one symptom at their injection site such as pain, redness or swelling and 55-83% will develop at least one additional symptom such as mild fever, fatigue or muscle aches. These are typically more common after the second dose than the first. Volunteers who received the Johnson & Johnson vaccine experienced only mild reactions after the shot including a sore arm and a fever in less than 10% of participants.

What’s important to remember is that these reactions to the vaccine are associated with the body’s immune response—so they are a good sign that the vaccine is doing its job to build protections for you in the future.

There have been additional rare, post-vaccination adverse events reported following COVID-19 vaccination. There have been a small number of cases of Guillain-Barré syndrome (GBS) that has been reported following receipt of the Janssen/J&J vaccine. GBS is a neurological disorder in which the body’s immune system damages nerve cells causing muscle weakness and sometimes paralysis. Additionally, rare cases of myocarditis and pericarditis (inflammation of the heart muscle or the tissue surrounding the heart) have been reported following mRNA (Pfizer and Moderna) vaccination.

Overall, these are rare events when looking at the millions of individuals vaccinated across the US and around the world, and the risk of acquiring COVID-19 far outweighs that of these vaccine-related complications.

Can I take pain relievers if I experience side effects from the vaccine?

If you have pain or discomfort after receiving the vaccine, it’s OK to take pain relievers. Remember, side effects after the COVID-19 vaccine can be a good sign that your body is building protection, and they should go away in a few days. If you have concerns about taking medications, check with your doctor.

What should I do if I think I am experiencing severe side effects from the vaccine?

When you get your vaccine, you will be monitored for a period of time in case of a severe reaction, which are extremely rare. If you think you might be having a severe allergic reaction after leaving the vaccine clinic, seek immediate medical care by calling 911. Learn more about COVID-19 vaccines and rare severe allergic reactions.

Discomfort from fever or pain at the injection site is quite normal. However, there are some instances where you should contact your doctor or healthcare provider:

  • If the redness or tenderness where you got the shot increases after 48-72 hours
  • If your side effects are worrying you or do not seem to be going away after a few days
What is lymph node swelling and how does it impact me?

COVID-19 vaccinations can cause harmless enlarged lymph nodes, usually under the arm and on the side the vaccine was given. This swelling of lymph nodes is a normal and expected part of the immune response as your body learns to fight the coronavirus. This type of swelling can also occur after other common vaccines, like the HPV and Flu vaccines, however the swelling related to the COVID-19 vaccine may be more robust and occur more often. Lymph node swelling typically happens 2-4 days after vaccination and lasts about 10 days.

Does the risk of lymph node swelling impact which arm I should receive my vaccine in?

For most patients, the risk of lymph node swelling will not change which arm the vaccinator will use to give you the vaccine. Your vaccinator will ask you which side you prefer at the time of vaccination and most people will choose their non-dominant arm (for example, your left side if you are right-handed) so that if you have any pain or swelling, it won’t be as bothersome to your activities.

If you have had surgery on your lymph nodes, such as for breast cancer, you should avoid vaccination on the side of your surgery, when possible. You should tell your vaccinator if you’ve had lymph node surgery and ask them to give you the vaccine on the other side. If you have had lymph node surgery on both arms, the vaccinator may choose to give you the vaccine in your thigh.

Does the risk of lymph node swelling from the COVID-19 vaccine change when I should have my breast cancer screening done?

There are times when the lymph node swelling related to vaccination may cause challenges interpreting normal screening tests, such as regularly scheduled mammograms or breast MRIs used to screen for breast cancer. Receiving the COVID-19 vaccine and completing your breast cancer screening are both important for your health.

It is safe to get your mammogram or breast MRI if you are overdue, as screening for breast cancer is important for one’s health. You should also not delay receiving your COVID-19 vaccine because a mammogram or breast MRI is scheduled. You should notify your mammogram or breast MRI technologist if you have received the COVID-19 vaccine.

If you are concerned about the potential risk of your mammogram or breast MRI results being impacted and you are not overdue for screening, you may wish to wait 4-6 weeks after you complete your full COVID-19 vaccine series to have this testing done. However, it is important to note that you should not delay mammography if you have already needed to do so due to the pandemic or are having any concerning symptoms such as a change in your breast or underarm such as pain or a lump.

If I’ve been diagnosed with COVID-19, should I wait to get the vaccine?

There are two reasons to wait to get vaccinated if you have recently had COVID-19, or if you have been exposed to someone who has COVID-19:

  1. If you are still in your isolation period as instructed by the Department of Public Health, usually 10-20 days from symptom onset or positive test result.
  2. If you have had COVID-19 and received treatment with monoclonal antibodies or convalescent plasma, the CDC recommends that you wait 90 days after treatment before being vaccinated to ensure maximum effectiveness of the vaccine.

Otherwise, you should get vaccinated as soon as possible. Due to the severe health risks associated with COVID-19 and the fact that re-infection is possible, people who previously tested positive can and should receive the COVID-19 vaccine when it is available to them.

If I get the first dose of a two-dose vaccine, then get infected with COVID-19, can I get the second dose of the vaccine?

If you get COVID-19 after your first dose of the Pfizer or Moderna vaccine, you should receive the second dose after the acute symptoms, such as fever, have gone away, and after you complete your isolation period, usually 10-20 days from the start of your symptoms or your positive test result.

Are the COVID-19 vaccines safe for people with allergies?

In general, all of the available COVID-19 vaccines are safe for use. People with many types of allergies may still get vaccinated safely. Talk to your doctor if you have a history of anaphylaxis or use of an EpiPen for any reason. If you have a severe allergic reaction (anaphylaxis) or have had allergic reactions to any of the vaccine components (such as polyethylene glycol or polysorbate), you should speak to your health care provider. If you have had a severe reaction to the first dose of an mRNA vaccine, you should speak with your health care provider before receiving the Johnson & Johnson vaccine.

If I had a severe reaction to my first mRNA vaccine, should I get the second?

If you have a history of severe allergy (anaphylaxis) or immediate reaction of any kind (e.g., anaphylaxis, difficulty breathing, hives, swelling around the mouth, throat or eyes) to a prior dose of a Moderna or Pfizer COVID-19 mRNA vaccine or any of its components (such as polyethylene glycol or polysorbate), you should not receive this vaccine.

If you are unable to receive your second mRNA vaccine due to a severe allergy, you may be a candidate to complete your vaccination with the Johnson & Johnson vaccine. Speak with your healthcare provider to see if receiving the Johnson & Johnson vaccine is safe for you based on your allergy history.

Your primary care provider may refer you to a specialist in allergies and immunology to provide more care or advice. Read more about severe allergic reactions here.

I am pregnant and/or breastfeeding. Should I get the COVID-19 vaccine?

The Centers for Disease Control and Prevention (CDC), the American College of Obstetrics and Gynecology, and the Society for Maternal-Fetal Medicine strongly recommend pregnant people, lactating people, and those thinking about becoming pregnant be vaccinated against COVID-19.

More than 20 health organizations urge COVID vaccinations for pregnant people, those who have recently been pregnant and those who plan to become pregnant. The CDC advice applies to all three vaccines: Pfizer-BioNTech, Moderna, and Janssen/Johnson & Johnson.

There is no evidence that the vaccine is harmful during pregnancy or breastfeeding based on the CDC’s review of data from more than 35,000 pregnant people who have been vaccinated. The data also showed that there were no safety concerns for their newborns. In fact, getting vaccinated can increase neonatal protection against COVID-19 by passing antibodies to your baby.

Meanwhile, pregnant people, if infected with COVID-19, are at higher risk of becoming ill from COVID-19 and transmitting it to their families and friends. Contracting COVID-19 while pregnant increases the risk of potential complications arising

If you are pregnant or breastfeeding and have additional questions, you should speak with your healthcare provider about COVID-19 vaccination.

For more information, read the CDC’s “COVID-19 Vaccines While Pregnant or Breastfeeding.”

I am planning to become pregnant. Should I get the COVID-19 vaccine?

Yes, the CDC strongly recommends getting vaccinated if you are pregnant, lactating, or planning to become pregnant. Since newborns are not yet eligible for vaccination, getting vaccinated now will provide protection for you and your family as well as neonatal protection for your baby

For more information, read the CDC’s “COVID-19 Vaccines While Pregnant or Breastfeeding.”

Which COVID-19 vaccines are available?

There are three vaccines currently available:

If you have questions about which vaccine to receive, talk to your health care provider.

What is an Emergency Use Authorization (EUA)? How is it different from full approval by the FDA?

The EUA was created for public health emergencies (like the COVID-19 pandemic). The FDA can issue an Emergency Use Authorization to allow a medical product to be used when there are no alternatives available.

The EUA process is different from the standard FDA vaccine approval processes because the EUA standard may allow authorization based on less data than required for approval, clearance, or licensing by the FDA. This enables the FDA to authorize the emergency use of medical products that meet the criteria much more quickly. Rather than taking years, the FDA can get drugs and vaccines that can save lives to the public now. Learn more about EUAs in this video.

How were the COVID-19 vaccines developed so quickly?

The federal government has been working since the pandemic started to make one or more safe and effective COVID-19 vaccines available as soon as possible. It provided money for many of the trials, and standardized paperwork between the bio-tech companies and hospitals involved. This sped up the process, which usually takes 1-2 years, and allowed scientists to begin clinical trials much more quickly than usual.

Are the available COVID-19 vaccines safe?

All vaccines that are authorized or approved by the FDA have been thoroughly tested and found to be safe and effective in preventing severe COVID-19. Like most vaccines, the COVID-19 vaccine may be associated with some adverse reactions, but the chance of having a bad reaction is far lower than the chance of getting COVID-19. Based on an updated risk-benefit analysis, use of mRNA COVID-19 vaccines is preferred over the Janssen COVID-19 Vaccine for all vaccine-eligible people ages 18 years or older for the primary series and booster doses. Visit the CDC’s website for more information.

Can I get COVID-19 from the vaccine?

No. You cannot get COVID-19 from the vaccine in the same way you cannot get the flu from the flu vaccine. The goal of vaccination is to teach the body’s immune system how to recognize and fight the virus that causes COVID-19. Sometimes this process can cause symptoms, such as fever, but these symptoms are normal and are actually a good sign that the body is building immunity. Learn more about how COVID-19 vaccines work.

It typically takes a few weeks for the body to build immunity after vaccination. That means it’s possible a person could be infected with the virus that causes COVID-19 or another virus just before or just after vaccination and get sick.

If I get a COVID-19 vaccine, do I still need to take other safety precautions?

Yes. The vaccine takes time to begin working. It can take around two weeks after each shot for the vaccine to be fully effective. Also, after you’ve been vaccinated you may still catch COVID-19 and have mild symptoms. Because you can still carry the virus, (even if it doesn’t make you visibly sick) it’s important to wear a mask and maintain social distancing to make sure you do not pass the virus to others who are not yet vaccinated. The combination of getting vaccinated and following CDC’s recommendations to protect yourself and others will offer the best protection from COVID-19.

What is myocarditis and the risk related to a mRNA vaccine?

Myocarditis is inflammation of the heart muscle. This can happen after viral infections like COVID-19 and, very rarely, after receiving mRNA COVID-19 vaccines.

Most people with myocarditis following vaccination recover completely with rest and simple treatment. However, myocarditis from COVID-19 infection can be very severe.

If you are unvaccinated:

  • You have a four to eight times higher risk of myocarditis from COVID-19 infection and ten times higher risk of hospitalization from COVID-19 infection.

If you received the COVID-19 vaccine:

  • The overall risk of myocarditis is extremely low – approximately 1 in 200,000.
  • Young males (12-29) have a slightly higher risk, but still very low – 1 in 14,000.
  • Young females (12-29) have a much lower risk of less than 1 in 100,000.

The CDC and FDA continue to closely monitor reports of myocarditis after COVID-19 vaccination.

Should I receive the Janssen/Johnson & Johnson (J&J) vaccine if I am a woman?

Based on an updated risk-benefit analysis, use of mRNA COVID-19 vaccines is preferred over the Janssen COVID-19 Vaccine for all vaccine-eligible people ages 18 years or older for the primary series and booster dose. Visit the CDC’s website for more information.

The J&J vaccine has undergone an additional extensive safety review after being associated with a very rare potentially serious medical condition called thrombosis with thrombocytopenia syndrome (TTS). This condition, while very rare, was seen with a higher frequency in women under the age of 50. Based on this risk, we recommend receipt of a mRNA vaccine in most situations unless you have a contraindication. While it is important to know about the potential risks of any COVID-19 vaccine including the risk of TTS with the J&J vaccine, it is clear that getting vaccinated with any available option is much safer than remaining unvaccinated.

Should I get the J&J vaccine if I am at risk for thrombosis?

If you have a history of an immune-mediated syndrome characterized by thrombosis and thrombocytopenia, such as heparin-induced thrombocytopenia (HIT), you should receive either the Pfizer or Moderna vaccine, not the Johnson & Johnson vaccine. Experts are unclear of the cause of thrombosis with thrombocytopenia syndrome (TTS) that is associated with the Johnson & Johnson vaccine, but it could be linked to HIT and so until we learn more, it is safest for you to receive either the Pfizer or Moderna vaccines.

Although the risk of thrombosis is increased during pregnancy, during the post-partum period and by certain hormonal contraceptives, experts believe that these factors do not make you more susceptible to TTS after getting the J&J vaccine.

Should I get the J&J vaccine if I am pregnant?

Based on an updated risk-benefit analysis, use of mRNA COVID-19 vaccines is preferred over the Janssen COVID-19 Vaccine for all vaccine-eligible people ages 18 years or older for the primary series and booster dose. Visit the CDC’s website for more information. However, you can receive any FDA-authorized COVID-19 vaccine if you are pregnant or were recently pregnant. The risk of thrombosis is increased during pregnancy and the post-partum period; however, there is no evidence connecting receiving the J&J vaccine and thrombosis with thrombocytopenia syndrome (TTS).

Should I take aspirin or anticoagulants before the J&J vaccine?

If you take aspirin or anticoagulants as part of your routine medications, you do not need to stop these medications prior to receipt of the J&J COVID-19 vaccine. If you do not, you should not take them before receiving any COVID-19 vaccine.

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