COVID-19 Vaccines and Childhood Cancer Survivors

Yes, it is safe to take the vaccine if you have a weakened immune system. But the vaccine may not work as well. If you received the Pfizer-BioNTech or Moderna vaccine, you may be eligible for additional doses.

In general, vaccines are recommended after a transplant to protect you from different infections. Visit Be the Match’s Vaccinations After Hematopoietic Cell Transplant for more information. Please talk to your transplant care team if you have questions.

In general, vaccines are recommended for people who have had their spleen removed. For more information on vaccines after spleen removal, visit the CDC page on this topic. Please talk to your health care provider if you have questions.

You should not get a COVID-19 vaccine if you have a history of severe allergic reaction to any component of the vaccine.

Pfizer and Moderna vaccines

Both the Pfizer-BioNTech and Moderna COVID-19 vaccines contain polyethylene glycol (PEG.) PEG is a primary ingredient in some laxatives and bowel preparations for colonoscopy procedures. It is also used in some injectable medications. Do not get the Pfizer-BioNTech or Moderna vaccine if you have a PEG allergy.

If you have a severe allergic reaction to the first dose of the Pfizer or Moderna vaccines, do not receive a second dose.

Johnson & Johnson vaccine

Polysorbate 80 is an ingredient in the Johnson & Johnson vaccine. Do not get the Johnson & Johnson vaccine if you have a polysorbate allergy.

PEG and polysorbate hypersensitivity

PEG and polysorbate are closely related to each other. Sometimes “cross-reactive hypersensitivity” may occur.

You may be concerned about getting any of the vaccines if you have an allergy to these ingredients.

But people who are allergic to PEG may be able to get the Johnson & Johnson vaccine. People who are allergic to polysorbate may be able to receive the Pfizer and Moderna vaccines.

Ask your doctor if can get the other type of vaccine. If the answer is yes, let your vaccine provider know you have a PEG or polysorbate allergy.

For more information, visit the CDC's COVID-19 Vaccines for People with Allergies.

Allergic reactions caused by food, pets, insect stings, or other things do not prevent you from getting a COVID-19 vaccine or need special precautions.

It is safe to receive a COVID-19 vaccine with an egg allergy.  Unlike some flu vaccines, current COVID-19 vaccines are not made using eggs.

As always, tell your vaccine provider about your medical history, including known allergies.

Pregnancy or planning a pregnancy

Pregnant women are at higher risk for problems caused by COVID-19.

Pregnant women and women who are planning to become pregnant should get the vaccine as soon as it is available for them.

Data shows that risks for pregnancy complications or miscarriage are not higher in vaccinated women.

There were no extra safety concerns among women vaccinated during pregnancy or in the babies born to vaccinated mothers.

Breastfeeding

Breastfeeding is still safe – and even recommended – during the pandemic. It is unlikely that COVID-19 vaccines during breastfeeding would be harmful to the mother or the baby. In fact, breast milk may offer some immune protection against COVID-19 for the baby. Studies have shown that antibodies against SARS-CoV-2, the virus that causes COVID-19 can be found in breastmilk after vaccination. Also, vaccination helps protect children in the same household who are not able to receive the vaccine. Both the American College of Obstetricians and Gynecologists (ACOG) and the Academy of Breastfeeding Medicine recommend the COVID-19 vaccine for breastfeeding women.

As always, women should contact their doctor with specific questions or concerns.

Yes, the vaccine is recommended even if you have had COVID-19. The immune response to illness with COVID-19 can vary widely. It is not known how long the protection lasts. But studies suggest that getting the vaccine after having COVID-19 improves the level of antibodies that protect you.

The CDC recommends that anyone who can receive one of the two mRNA vaccines (Pfizer-BioNTech or Moderna) do so. However, the Johnson & Johnson vaccine is available for those over 18 who cannot take an mRNA vaccine due to issues such as a severe allergy.

This recommendation is based on:

• Evidence and effectiveness
• Safety
• Adverse events

The Advisory Committee on Immunization Practices for the prevention of COVID-19 recommends receiving any vaccine—including the Johnson & Johnson vaccine—over not being vaccinated. 

Side effects after COVID-19 vaccine have been reported. But serious reactions have been extremely rare.

Side effects may include temporary redness, soreness, or swelling at the injection site. Headache, fever, fatigue, chills, nausea, or body aches can occur. These reactions are usually mild and go away in a couple of days. Ibuprofen and acetaminophen may help relieve some of the symptoms.

In very rare cases, myocarditis and pericarditis have been reported. It’s important to remember that the risks for these conditions are much lower from the vaccine than they are from a COVID-19 infection.

There have been a few reported cases of allergic reactions. But these have been in people who have a serious allergy to the vaccine or its components.

If you choose not to get the vaccine, you increase your risk of illness from COVID-19. In addition, by not getting the vaccine, you put those who live and interact with you on a daily basis at risk.

People are considered fully vaccinated:

• 2 weeks or more after they have received the final dose of either the Pfizer-BioNTech or Moderna vaccine
• 2 weeks after getting 1 dose of the Johnson & Johnson vaccine

The Moderna and Pfizer-BioNTech vaccines are mRNA vaccines.

The Johnson & Johnson vaccine is a viral vector vaccine.

The mRNA vaccines teach our cells how to make copies of proteins on the surface of the virus that causes COVID-19.

The protein triggers the body’s immune response to recognize and respond if exposed to the germ in the future.

The mRNA vaccine can’t make you sick. It is quickly dissolved in the body. It cannot change your DNA in any way.

The Johnson & Johnson vaccine is a viral vector vaccine. It targets the spike proteins on the surface of the virus.

A viral vector vaccine uses a harmless version of a different virus called a “vector,” to deliver information to your body that helps it protect you.

The vaccine teaches your body how to make copies of proteins on the surface of the virus. If you are exposed to the real virus later, your body will recognize it and know how to fight it off.

The vaccine does not contain the virus that causes COVID-19. It cannot give you COVID-19.

The COVID-19 vaccines authorized or approved in the U.S. do not have live virus. They are safe, even if your immune defenses are weakened.

Teamwork among scientists, clinicians, and public health workers made rapid development and testing possible. These same groups continue to work together to monitor rare side effects and immune responses over time.

The U.S. Food and Drug Administration (FDA) regulates vaccines. The FDA works with scientists, vaccine developers, and federal and state agencies to make sure vaccines meet rigorous standards for safety and effectiveness.

Data is independently evaluated by FDA scientists and physicians. Based on the data, the FDA can authorize a COVID-19 vaccine under Emergency Use Authorization (EUA) provisions.

After authorization, the clinical trials continue. More data will become available. The companies developing COVID-19 vaccines are working toward a full FDA approval. The FDA, CDC, and other health agencies will continue to monitor the vaccine.

For more information, visit the FDA’s Emergency Use Authorization for Vaccines Explained.