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?

Anyone 5 and older is eligible to be vaccinated.

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.

What vaccines are you offering at your vaccination clinics?

Visit our Vaccine Clinic page for more information on the vaccines we are offering. We receive our supply of vaccines from the state, and we provide patients whichever vaccine we have available.

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. Here’s an overview for each available vaccine.

Moderna: The primary series includes two doses 28 days apart. For people who are moderately to severely immunocompromised, a third dose is recommended at least 28 days after the second dose. People ages 18 and older should get a booster shot at least six months after completing their primary COVID-19 vaccine series. You can receive a different type of vaccine for your booster shot.

Pfizer: The primary series includes two doses 21 days apart. For people who are moderately to severely immunocompromised, a third dose is recommended at least 28 days after the second dose. People ages 18 and older should get a booster shot at least six months after completing their primary COVID-19 vaccine series. You can receive a different type of vaccine for your booster shot.

Janssen/Johnson & Johnson (J&J): The primary vaccination is only one dose. People ages 18 and older should get a booster shot at least two months after their primary COVID-19 vaccine. You can receive a different type of vaccine for your booster shot.

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 request proof of my COVID-19 vaccination?

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 strong protection against COVID-19. For some people, an additional dose can offer added protection and a booster shot several months after your primary vaccine series can prevent waning immunity.

Some people are eligible for an additional/third dose and others are eligible for a booster. What’s the difference?

The difference relates to a person’s immune status.

A COVID-19 booster shot is given two or six months after the initial vaccine due to concerns the vaccine’s effectiveness could decrease over time. An additional/third dose of a COVID-19 vaccine is given as early as 28 days after the second dose of a Pfizer or Moderna COVID-19 vaccine to help people with severely compromised immune systems who may not have had a full immune response to the initial vaccine series produce a stronger response.

Who should receive a booster shot?

Anyone ages 18 and older who:

  • Initially received the Pfizer or Moderna COVID-19 vaccine and completed their primary vaccination series six or more months ago; or
  • Initially received the J&J COVID-19 vaccine and completed their primary vaccination two or more months ago.
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.

Who is eligible for an additional/third dose?

People with moderately to severely compromised immune systems and who initially received a COVID-19 vaccine made by Moderna or Pfizer/BioNTech are eligible for an additional dose of the same brand of vaccine they originally received.

This is a small group of people – about 3 percent of the adult population. This group is especially vulnerable to complications of COVID-19 because they are at risk of serious, prolonged illness. This includes people who have:

  • Been receiving active cancer treatment for tumors or cancers of the blood
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
  • Have a moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Have advanced or untreated HIV infection
  • Are on active treatment with high-dose corticosteroids or other drugs that may suppress your immune response

If you’re not sure if you are eligible, speak with your healthcare provider.

Where can I get an additional or booster dose of the vaccine?

COVID-19 vaccines and boosters are available at more than 500 locations in Massachusetts, including retail pharmacies. If you are eligible, here’s how to find a location near you:

  • Visit the Massachusetts online directory to view hundreds of vaccination sites, and search for locations offering boosters with available appointments. Or, visit your state’s website to find a location near you.
  • Call the Massachusetts COVID-19 Vaccine Resource Line (2-1-1) and follow the prompts. The Resource Line is available in English and Spanish and has translators available in approximately 100 additional languages.
  • Beth Israel Lahey Health has limited capacity for booster shots. Check our COVID-19 Vaccine Clinics page for the latest information on our clinics to schedule an appointment.
More Information

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

Who is eligible to be vaccinated?

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 5-15 years.

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.

Is the vaccine safe?

The vaccine is considered safe and effective for children, but it does come with potential side effects such as achiness and/or a sore arm. The dose provided to children ages 5-11 is one-third of the dose provided to people ages 12 an older, and a Pfizer clinical trial demonstrated it to be just as effective for children as a regular dose is for their older counterparts.

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 2nd 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 percent 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 was exposed to someone with COVID-19 recently, when can I get vaccinated?

If you have been exposed to someone with COVID-19, you cannot be vaccinated until after you have completed the quarantine period, which is generally 14 days after your date of exposure.

If you have an appointment, reschedule it to at least 14 days after your exposure. If you develop COVID-19, you should not get vaccinated until you have completed the home isolation period as instructed by the Department of Public Health, usually 10-20 days after your symptom onset or positive test result.

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 have been authorized or approved?

There are three vaccines currently available:

Pfizer-BioNTech: This 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 5-15 years, for the administration of an additional (third) dose in certain immunocompromised people, and for a single booster dose for people ages 18 and older.

Moderna: This vaccine is available under EUA for people 18 and older, for an additional (third) dose for some immunocompromised people and for a single booster dose for people ages 18 and older.

Janssen/Johnson & Johnson (J&J): This vaccine is available under EUA for people 18 and older and for a single booster dose for people ages 18 and older.

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 three vaccines 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.

Which vaccine is the most effective?

It’s difficult to directly compare one vaccine to another because the clinical trials use different measures to evaluate effectiveness. The good news is that all the vaccines that are currently available are safe and highly effective.

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.

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

Women can receive any COVID-19 vaccine that is available to them. The J&J vaccine has recently 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 our review of the data and our current available supply of other vaccine options (Pfizer and Moderna), Beth Israel Lahey Health will be providing the Pfizer or Moderna vaccines as a first choice to women under 50. If a woman under 50 prefers the option of a single dose vaccine, the J&J vaccine may be given (if supplies are available), but we will ensure all of your questions about the risk of TTS have been answered.

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?

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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