COVID-19 Vaccine Facts for People With Breast Cancer
In the United States, the following three vaccines are used to reduce the risk of getting COVID-19:
The Pfizer-BioNTech vaccine, which is marketed under the brand name Comirnaty, and has full approval from the U.S. Food and Drug Administration (FDA) for people ages 16 and older. The FDA also has authorized the Pfizer vaccine for emergency use in children and young adults ages 5 to 15. The Pfizer vaccine consists of two injections, which are given three weeks apart in the upper arm muscle.
The Moderna vaccine, which is marketed under the brand name Spikevax, and has full approval from the FDA for people ages 18 and older. The Moderna vaccine consists of two injections, which are given four weeks apart in the upper arm muscle.
The Johnson & Johnson (J&J) vaccine, which has limited emergency use authorization from the FDA for people ages 18 and older who have had a severe allergy to an mRNA vaccine, are unable to get an mRNA vaccine because these aren’t available, or strongly prefer the J&J vaccine. The J&J vaccine is given as a single injection in the upper arm muscle.
Research shows the mRNA vaccines are safe and reduce the risk of getting COVID-19, especially serious illness and death from the disease. Because these vaccines do not contain live viruses, they can be used in people with weakened immune systems, including people who are receiving treatment for cancer.
The FDA and the U.S. Centers for Disease Control and Prevention (CDC) recommend that people get the Pfizer or Moderna vaccine instead of the J&J vaccine if possible.
If you have a severe allergic reaction or an immediate allergic reaction to the first dose of either the Pfizer or Moderna vaccine, the CDC recommends that you do not have a second dose. An immediate allergic reaction typically happens within four hours of getting vaccinated. Symptoms may include hives, swelling, and respiratory distress (or wheezing).
Currently, you are considered fully vaccinated two weeks after the second dose of the Pfizer or Moderna vaccine or two weeks after the single shot of the J&J vaccine. A booster shot is recommended for most people, and an additional booster is recommended for some people.
The FDA has authorized the Pfizer and Moderna COVID-19 vaccine booster shots to all adults ages 18 and older. Boosters for any of the COVID vaccines can be mixed and matched. This means you can get a booster dose of either of the mRNA vaccines available in the United States, regardless of which vaccine you had initially.
Eligibility for COVID booster shots varies, depending on which vaccine you initially received. Adults ages 18 and older whose initial vaccine was:
Pfizer are eligible for a booster five months after their second shot
Moderna are eligible for a booster five months after their second shot
J&J are eligible for a booster at least two months after their shot
The CDC also says people can get COVID-19 vaccines, including boosters, on any schedule, including:
on the same day they get other vaccines, including the flu shot, as long as they get the injections in different sites (for example, one injection in each arm)
regardless of when they get other vaccines, including the flu shot
The FDA authorized emergency use of a single Pfizer COVID-19 vaccine booster dose to be given five months after the second Pfizer vaccine shot for children and adolescents between the ages of 5 and 17.
On March 29, 2022, the FDA authorized a second booster dose of the Pfizer and Moderna COVID-19 vaccine at least four months after their first booster (third dose) for:
adults ages 50 and older
young children between the ages of 12 and 17 who have had solid organ transplants or are immunocompromised
It’s important to know that COVID vaccine recommendations are different for people with weakened immune systems (called immunocompromised). Several breast cancer treatments, including chemotherapy, certain targeted therapies, and immunotherapy, can weaken your immune system. People with moderately to severely compromised immune systems are especially vulnerable to COVID-19, and may not build the same level of immunity to the virus as people who are not immunocompromised after being fully vaccinated. If you’re currently being treated for breast cancer, it’s a good idea to ask your doctor if you should follow these recommendations for moderately to severely immunocompromised people:
If your initial vaccine was Pfizer or Moderna, the CDC recommends you get a third dose of the same vaccine you received initially at least 28 days after your second dose.
After the third dose of either the Pfizer or Moderna vaccine, you should receive a booster dose of either of the two mRNA vaccines at least three months after your third dose.
If your initial vaccine was J&J, the CDC recommends you get a second dose of either the Pfizer or Moderna vaccine at least 28 days after receiving the vaccine. The CDC also recommends a booster dose of either the Pfizer or Moderna vaccine at least two months after your second dose. The FDA has limited emergency use authorization to people ages 18 and older who have had a severe allergy to an mRNA vaccine, are unable to get an mRNA vaccine because these aren’t available, or strongly prefer the J&J vaccine.
It’s also important to know that the National Comprehensive Cancer Network (NCCN) — an alliance of leading cancer centers — recommends a second booster dose of either mRNA vaccine for immunocompromised people. This means you'd get a total of five shots: three primary mRNA doses plus two booster doses.
Even though being vaccinated protects you from serious illness, it’s still possible to get what’s called a breakthrough infection, but these are rare and the symptoms are usually mild. It’s also possible to give someone else COVID-19 if you’re exposed to the virus after being vaccinated. So it’s recommended that mask wearing and physical distancing in public continue for some time.
Experts recommend that most people diagnosed with cancer or who have a history of cancer should get a COVID-19 vaccine. Still, you should talk to your doctor about whether getting a COVID-19 vaccine and booster shots is the right decision for your individual situation.
Evusheld antibody therapy
The FDA has granted emergency use authorization to Evusheld (chemical name: tixagevimab combined with cilgavimab), an antibody therapy used to prevent COVID-19 in people age 12 and older who have moderately to severely compromised immune systems or cannot get a COVID-19 vaccine because of a severe allergic reaction to its ingredients. Evusheld works differently from a vaccine, and may be an option for immunocompromised people who may not develop enough immunity after a COVID-19 vaccine.
Whereas the COVID-19 vaccines use your immune system to make special proteins called antibodies to fight the virus, Evusheld contains two different types of antibodies designed in a lab to fight the virus. Each of Evusheld’s antibodies attach themselves to different parts of the virus to stop it from entering the body’s cells and making you sick.
Evusheld is given as two separate injections, one after the other, into muscle. The most common side effects are headache, fatigue, and cough. People should be monitored for severe allergic reactions for at least one hour after receiving the injections. In clinical trials, people with a history of heart problems were more likely to have heart attacks or heart failure after receiving Evusheld. If you have a history of heart-related medical conditions, it’s a good idea to talk with your doctor about Evusheld’s risks and benefits.
The mRNA vaccines: Pfizer and Moderna
The Pfizer and Moderna vaccines work by using genetic material called messenger RNA (mRNA). The mRNA vaccines contain a small piece of the coronavirus’s mRNA, which tells your body to make copies of a protein in the virus called the spike protein. Your immune system then builds up immune cells and special proteins (antibodies) to fight the spike protein. So, if you’re ever exposed to the COVID-19 virus, your immune system is ready to recognize the virus and protect you from infection.
The Johnson & Johnson vaccine
The J&J COVID-19 vaccine works differently from the mRNA vaccines. The J&J vaccine is called a viral vector vaccine. It is made from an adenovirus (the type of virus that causes the common cold). The adenovirus in this vaccine is not a live virus — it has been changed in a lab so that it can’t reproduce in the body or cause disease. Also, a gene found in the COVID-19 virus has been added to this modified adenovirus. This gene tells your body to make copies of the COVID-19 virus’s spike protein. Then your immune system gets activated and builds up immune cells and antibodies to fight the spike protein. Once this happens, your immune system is ready to protect you if you are exposed to the COVID-19 virus.
The FDA has issued warnings about two rare but serious side effects linked to the J&J vaccine:
a blood clotting disorder called vaccine-induced immune thrombotic thrombocytopenia
Guillain-Barré syndrome is a rare disorder of the nervous system. In Guillain-Barré syndrome, the body’s immune system attacks the peripheral nervous system, the network of nerves outside the brain and spinal cord. Symptoms range from brief muscle weakness in mild cases to paralysis in severe cases. Doctors don’t know the exact cause of Guillain-Barré syndrome, but they do know that it is not contagious or inherited.
The FDA warned that the J&J vaccine may lead to a higher risk of Guillain-Barré syndrome in the six weeks after vaccination in a small number of people. A warning about Guillain-Barré syndrome has been added to the J&J vaccine fact sheets and the CDC website.
It’s important to know that Guillain-Barré syndrome is a rare side effect of the J&J vaccine and has developed in only a small number of people. According to the CDC, the cases of Guillain-Barré syndrome were mostly reported about two weeks after a person was vaccinated and mostly in men ages 50 and older.
You should seek medical attention right away if you develop any of the following symptoms after receiving the J&J vaccine:
weakness or tingling, especially in the arms or legs, that gets worse and spreads to other parts of your body
difficulty using facial muscles, including speaking, chewing, or swallowing
double vision or inability to move your eyes
difficulty controlling your bladder or bowels
A thrombosis is a blood clot. Most cases were reported about nine days after the J&J vaccine, and the clot was in the veins that drain blood from the brain. This is why you may have seen news about the disorder called cerebral venous sinus thrombosis (CVST). The blood clots also can form in the legs, abdomen, or heart and can cause a stroke.
All the people who developed blood clots after the J&J vaccine had thrombocytopenia. Thrombocytopenia means a person has very low levels of platelets, a type of cell that helps the blood to clot. More research is needed, but it is thought that the J&J vaccine may trigger an immune system response that is destroying platelets but also causing the platelets to release tiny particles that lead to blood clots forming.
A warning about the rare clotting disorder has been added to the J&J vaccine fact sheets and the CDC website.
"What I know about conditions like this, such as [a very similar condition caused by the blood thinner heparin called HITT], is that they’re very rare. I don’t want to say it’s extremely rare,” explained Brian Wojciechowski, M.D., a medical oncologist and Breastcancer.org medical adviser. “I think we need to look at it more. I think the FDA needs to investigate any other cases that may have come up. But it should be fairly uncommon.”
Symptoms of these rare clots include:
severe abdominal pain
severe leg pain or redness, especially in only one leg
shortness of breath or chest pain
Because these rare clots are seen in people with very low platelet counts, they can’t be treated with heparin, the most commonly used blood thinning medicine.
If you received the J&J vaccine 30 or more days ago, your risk of developing the rare clotting disorder is very low. There are no known cases that started three weeks after receiving the vaccine.
If you received the J&J vaccine in the past few days, the flu-like symptoms you may have are normal. But you should contact your doctor or seek medical care immediately if you have any of the following symptoms:
severe abdominal pain
severe leg pain or redness, especially in only one leg
shortness of breath or chest pain
It’s important to report any of these symptoms to your doctor and say that you’ve had the J&J vaccine and the date you received it.
COVID-19 vaccine side effects
The most common side effects of the COVID-19 vaccines have been:
pain or soreness in the arm where you receive the injection
muscle or joint pain
These side effects are usually minor, last a few days, and happen more often after the second dose of the mRNA vaccines. Side effects are expected and are actually a sign that the vaccine is working by causing an immune response. Research shows that women may experience worse side effects from the COVID-19 vaccines than men.
Some people have experienced swollen or enlarged lymph nodes, including the axillary lymph nodes (the lymph nodes in the armpit) on the side where the injection was given. Doctors call this “axillary adenopathy.”
If you have received treatment for breast cancer, and especially if you’ve had underarm lymph nodes removed, you could experience lymphedema or worsening of lymphedema as a side effect of the COVID-19 vaccines. To lower this risk, people with a history of breast cancer should avoid getting the vaccine injected into the arm on the side of the body affected by the breast cancer. If you have a history of breast cancer in both breasts, ask your doctor which arm should be injected. The COVID-19 vaccines can be given in the upper hip area as an alternative, but the providers at your vaccination site may not be trained in or comfortable with giving the vaccine this way, so this may not be a feasible option for most people at this time.
For people without a history of breast cancer, swelling of the axillary lymph nodes after vaccination is harmless, but they can feel like breast lumps and cause some women to worry they could be a sign of breast cancer. These swollen lymph nodes can also show up on a mammogram, even if you can’t feel them. This could result in a false positive, which is when a mammogram shows an abnormal area that looks like a cancer but turns out to be normal. A false positive mammogram result can lead to unnecessary stress and additional testing.
The Society of Breast Imaging has recommended that women should try to schedule their routine screening mammogram at least a month after getting vaccinated so that any swelling in the axillary lymph nodes has time to go away. But if your mammogram is already scheduled, it is not necessary to cancel your mammogram or your COVID-19 vaccine appointment. Just be sure to tell the person performing your mammogram if you were recently vaccinated, in which arm, and whether it was your first or second dose. This helps the breast radiologist accurately interpret your mammogram result.
People are monitored for about 15 to 30 minutes after receiving each injection to make sure they don’t have a rare serious allergic reaction to the vaccine. If you have a history of severe allergic reactions, you should talk with your doctor and perhaps see an allergist or immunologist to figure out whether getting a COVID-19 vaccine is safe for you.
The person who gives you the COVID-19 vaccine should ask if you have had any severe allergic reactions in the past. Make sure you tell them if you have experienced an allergic reaction so they monitor you for at least 30 minutes after you receive your injection. Vaccination centers should have medicines, equipment, and safety measures in place to care for anyone who has an allergic reaction. It’s a good idea to ask if these safety measures are in place at your vaccination center if you have had a serious allergic reaction in the past.
It’s important to know if you have had an allergic reaction to polyethylene glycol (PEG) or polysorbate in the past. These ingredients are in certain medicines, including some cancer therapies, and are also used in the COVID-19 vaccines.
The Pfizer and Moderna vaccines contain PEG. They do not contain polysorbate, but polysorbate is closely related to PEG. The J&J vaccine contains polysorbate.
The CDC has said that if you have had a severe allergic reaction to PEG in the past, then you should not get the Pfizer or Moderna mRNA vaccines and should ask your doctor about getting the J&J vaccine instead. If you have had a severe allergic reaction to polysorbate in the past, then you should not get the J&J vaccine and should ask your doctor about getting one of the mRNA vaccines instead.
Doctors call medicines that contain PEG “pegylated.” Medicines are sometimes pegylated to change how they work in the body. Sometimes there are pegylated and non-pegylated versions of the same medicine.
Pegylated cancer medicines include:
Doxil (chemical name: pegylated liposomal doxorubicin), a chemotherapy medicine used to treat breast cancer. Also marketed as Caelyx in some countries.
Neulasta (chemical name: pegfilgrastim), a medicine used to treat neutropenia (low white blood cell levels) during chemotherapy.
Polysorbate is used in many medicines to change how they work in the body or as a preservative. Cancer medicines that contain polysorbate include:
Abraxane (chemical name: albumin-bound or nab-paclitaxel)
Adriamycin (chemical name: doxorubicin)
Aranesp (chemical name: darbepoetin alfa)
Cinvanti, Emend (chemical name: aprepitant)
Doxil (chemical name: pegylated liposomal doxorubicin); also marketed as Caelyx in some countries
Epogen (chemical name: epoetin alfa)
Methotrexate (marketed with many brand names)
Procrit (chemical name: epoetin alfa)
Taxol (chemical name: paclitaxel)
Taxotere (chemical name: docetaxel)
If you have had a severe allergic reaction to any of these medicines, talk to your doctor about whether getting a COVID-19 vaccine is safe for you.
The CDC does recommend that you get the second shot of either the Pfizer or Moderna vaccines if you get a red, itchy, swollen, or painful rash on the arm where you got your first shot. Known as “COVID arm,” these rashes can show up within a few days to more than a week after the first shot and can be large. If you get a rash after your first shot, let your vaccine provider know so you can determine whether you should get the second shot in the other arm.
When you’re fully vaccinated
As more people get vaccinated against COVID-19, the CDC continues to update its guidelines on what fully vaccinated people can do. These guidelines also take into account how contagious the current strains of COVID-19 are.
The CDC recommends that fully vaccinated people should wear masks in indoor public settings if they live in areas where COVID-19 is spreading at “substantial” or “high” levels. This CDC tool shows you whether COVID-19 is spreading at low, moderate, substantial, or high levels where you live.
All unvaccinated people should wear a mask in public indoor and outdoor settings.
The CDC also recommends that everyone should wear masks in schools. Additionally, the CDC also says that all fully vaccinated people might want to wear a mask in public indoor settings for extra protection, especially if they have a weakened immune system or live with someone who has a weakened immune system or a higher risk of severe illness from COVID-19.
If you’re immunocompromised, the CDC recommends that you talk to your doctor about taking extra precautions, even if you are fully vaccinated. If you know someone who is immunocompromised or has a medical condition, such as cancer, that puts them at higher risk for severe complications from COVID-19, it’s a good idea to wear a mask when you visit them indoors, even you both are fully vaccinated. Learn more about the types of masks that are most effective against new strains of the virus, such as omicron.
Certain breast cancer treatments, including chemotherapy, targeted therapy, and immunotherapy, can weaken the immune system. The COVID-19 vaccines may offer less protection in people who are receiving cancer treatment, so you may need to continue taking extra precautions.
Even if you’re fully vaccinated, the CDC recommends the following additional precautions:
wear a mask in public indoor settings if you live in an area where COVID-19 is spreading at “substantial” or “high” levels
get tested if you are around someone you suspect has COVID-19, and wear a mask in public indoor settings for two weeks or until you get a negative test result
talk to your doctor about whether you need to continue to wear a mask and take other precautions if you or someone you live with is receiving medical treatments that can weaken the immune system, or is at risk for severe illness from COVID-19
wear a mask that fits snugly where required by law or other rules and regulations
wear a mask when you travel on planes, buses, trains, and other types of public transportation
wash your hands with soap and water for at least 20 seconds or use hand sanitizer after you’ve been in public spaces
watch out for symptoms of COVID-19, especially if you’ve been around someone who is sick
get tested and quarantine if you develop symptoms
Thompson MG, et al. “Prevention and Attenuation of Covid-19 with the BNT162b2 and mRNA-1273 Vaccines.” New England Journal of Medicine. June 30, 2021. Available at: http://dx.doi.org/10.1056/NEJMoa2107058.
— Last updated on August 25, 2022, 8:20 PM