Answers to Your Questions About the COVID-19 Vaccine

March 4, 2021
Julie Gralow, MD, FACP, FASCO

Julie Gralow, MD, FACP, FASCO, is the Chief Medical Officer (CMO) and Executive Vice President of the American Society of Clinical Oncology (ASCO). Previously, she was the Jill Bennett Endowed Professor of Breast Cancer at the University of Washington School of Medicine, Professor in the Clinical Research division of the Fred Hutchinson Cancer Research Center, and Director of Breast Medical Oncology at the Seattle Cancer Care Alliance. Dr. Gralow is the founder of the Women’s Empowerment Cancer Advocacy Network (WE CAN), supporting patient advocates in low-resource and middle-resource countries. In 2018, Dr. Gralow received the ASCO Humanitarian Award for her work in empowering women with cancer and survivors around the globe.

How can we know the vaccines are safe if they were developed and authorized so fast?

Since the start of the pandemic the medical community has been working to make COVID-19 vaccines available as soon as possible. Although this accelerated timeline is historic, safety has always been a top priority. There have been strict protections in place to help ensure that the COVID-19 vaccines are safe. COVID-19 vaccines have gone through a rigorous, multi-step testing process, including large clinical trials that involve tens of thousands of people.

Three COVID-19 vaccines have now received Emergency Use Authorization (EUA) by the U.S. Food and Drug Administration (FDA). This means that the FDA has carefully reviewed all safety data from clinical trials and authorized their emergency use because the expected benefits are felt to far outweigh potential risks. The FDA continues to monitor the safety of COVID-19 vaccines in order to make sure any possible long-term side effects as well as very rare side effects are identified.

Will the vaccine hurt? Will it make me very sick?

The COVID-19 vaccines have been shown to be safe and effective in the general population. There are no specific safety concerns associated with use of COVID-19 vaccines in patients undergoing cancer care.

Common side effects of the COVID-19 vaccine include pain in the arm where the vaccine was given, tiredness, headache, muscle and joint pain, chills, and fever. Side effects tend to occur within 2 to 3 days of the vaccine and may be more noticeable with the second dose. They often go away within a week, usually in a few days. Side effects are more common in those younger than 55 years of age. These side effects are generally a sign that your immune system is doing exactly what it is supposed to do—working and building up protection to disease.

A small number of people have developed an allergic reaction to ingredients of the vaccines, so it is important to talk to your health care provider if you have ever had a reaction to a previous vaccine or medication.

Some people have reported temporary swelling of the lymph nodes in the axilla (armpit) or supraclavicular area (above the collar bone) on the side on which they received the shot. Because this possible side effect may be mistaken for a sign of breast cancer, it’s best to delay a mammogram for up to a month after receiving the COVID-19 vaccine.

Will the vaccine give me COVID-19 or make me test positive for it?

None of the FDA-approved vaccines contain the live virus (SARS-CoV-2) that causes COVID-19. This means that they cannot make you sick with COVID-19 or transmit it to others.

None of the authorized vaccines can cause you to test positive on COVID-19 viral tests, which are used to see if you have a current infection. If your body develops an immune response, which is the goal of vaccination, there is a possibility you may test positive on some COVID-19 antibody tests. Antibody tests indicate you had a previous infection. Experts are currently looking at how COVID-19 vaccination may affect antibody testing results.

How do the vaccines work? Will the mRNA vaccines change my DNA?

Three COVID-19 vaccines are currently available in the United States:

  • Pfizer BioNTech vaccine

  • Moderna vaccine

  • Johnson & Johnson (Janssen) vaccine

COVID vaccines work by teaching the body’s immune system how to recognize and fight the virus that causes COVID-19, and this protects you from getting sick with COVID-19 infection. All have been shown to be effective at both lowering the risk of getting COVID-19 and lowering the risk of getting severe disease if you are infected.

The Pfizer BioNTech and Moderna vaccines contain messenger RNA (mRNA). mRNA is a type of genetic material from the COVID-19 virus that gives our cells instructions for how to make a harmless protein that is unique to the virus. After receiving the vaccine, the mRNA enters cells in the body and tells them to make copies of the COVID-19 virus’s “spike” protein, which normally helps the virus infect human cells. This doesn’t cause disease, but it helps teach the immune system to recognize and act against the virus if the body is exposed to it in the future. The mRNA from a COVID-19 vaccine does not enter the nucleus of the cell, which is where our DNA is kept. This means the mRNA cannot affect or interact with our DNA in any way.

The Johnson & Johnson (Janssen) vaccine is a vector vaccine. It contains a weakened version of a live virus, which is a different virus than the one that causes COVID-19. This weakened live virus has genetic material from the COVID-19 virus inserted in it. This is called a viral vector. The adenovirus in this vaccine has been changed so that it can no longer reproduce in the body or cause disease. The virus has been changed in the lab so that it contains a gene (a piece of DNA) for the COVID-19 virus’s spike protein. The genetic material gives cells instructions to make copies of the spike protein that is unique to the COVID-19 virus. This prompts our bodies to build immune responses to detect and fight the virus if we are ever exposed to it in the future.

Both the COVID-19 mRNA vaccines and the vector vaccine work with the body’s natural immune defenses to develop immunity to disease. Our bodies recognize that the COVID-19 proteins should not be there and build specific white blood cells, called T cells and B cells, that remember how to fight the virus that causes COVID-19.

Which COVID-19 vaccine is the best?

At this time, no medical organizations have recommended getting 1 type of COVID vaccine over another, either for people with cancer or cancer survivors or for others. Many health experts believe that getting the vaccine as soon as it becomes available to you, whichever one it is, is most important, rather than waiting to get a specific vaccine.

Why are 2 shots needed for some of the vaccines?

The COVID-19 mRNA vaccines are 2-dose vaccines, and both doses are recommended to ensure the best protection against COVID-19. The first shot primes the body’s immune system, helping it recognize the virus, and the second shot, given several weeks later, strengthens the response from the immune system.

Getting vaccinated is a personal choice. Why does it matter if I get the vaccine?

Both the COVID-19 virus and the vaccines are new, and there is much we don’t know. What we do know is that COVID-19 has caused very serious illness and death for a lot of people. We also know that people with cancer are at high risk of complications from COVID-19.

Being protected from getting sick is important because even though many people with COVID-19 have only a mild illness, others may get a severe illness, have long-term health effects, or even die. There is no way to know how COVID-19 will affect you, even if you don’t have an increased risk of developing severe complications. If you get COVID-19, you also risk giving it to others who may get very sick.

Getting vaccinated is one of several steps you can take to protect yourself and others from COVID-19. All 3 of the authorized vaccines have been found to significantly lower the risk of being infected with COVID-19. They have also been shown to be very effective at lowering the risk of severe disease, being hospitalized, or dying from COVID-19 if you are infected.

Stopping a pandemic requires using all the tools available. Masks and social distancing help reduce the chance of being exposed to the virus or spreading it to others. Vaccines work with your immune system so your body will be ready to fight the virus if you are exposed. Together, vaccination and following public health recommendations to protect yourself and others from virus exposure offer the best protection from COVID-19.

I’m receiving cancer treatment that is suppressing my immune system. How do we know that my body will respond to the vaccine?

The COVID-19 vaccine clinical trials that have been completed enrolled very few people receiving active cancer treatment, so there is limited data on the effectiveness and safety of the approved vaccines in people with cancer. How well the vaccine works in people with cancer and a weakened immune system is currently unknown. That said, there is no reason to believe that the COVID-19 vaccines are not safe for people with cancer. The vaccines do not pose a safety risk for people who are immunosuppressed. However, they may have lowered immune responses when compared with individuals in the general population.

Researchers are studying when the best time is for people on active cancer treatment to receive the COVID vaccine so it is as effective as possible. Some treatments, such as chemotherapy, immunotherapy, or radiation therapy, may make the vaccine less effective, so giving the vaccine between or after treatments may be recommended by your doctor. It is recommended that cancer treatments should not be interrupted so you can receive the vaccine. The vaccine will not affect your cancer treatment. You may need to delay the vaccine if you have received a bone marrow/stem cell transplant or have received a cellular therapy, such as a chimeric antigen receptor (CAR) T-cell therapy.

Data from clinical trials have shown that vaccines lower your chances of getting COVID-19 disease and having complications, but it is still unclear if these vaccines prevent infection with COVID-19 and  transmitting the disease to others. Therefore, vaccinated patients and close contacts should continue to wear masks, maintain social distancing guidelines, and follow other recommendations for preventing COVID-19. Caregivers, other members of the household, and other close contacts are strongly encouraged to get vaccinated when it becomes available to them.

Who can I talk to if I have more questions about these vaccines?

Since the situation is different for every person, it is best to discuss any questions or concerns about the COVID-19 vaccine with your doctor or your cancer care team. They can advise you based on your personal medical history, including your cancer diagnosis and treatment, as well as taking into account your home, work, and living circumstances, as well as your personal thoughts and concerns about COVID-19 vaccination and medical research. Talking openly about vaccination with a health care professional who you trust is important. There is much information and ongoing public dialogue about the COVID-19 vaccines—separating facts and evidence from myths and misinformation can be difficult.

Minority and underserved communities have been deeply impacted by COVID-19, which has magnified existing societal health inequities. Many individuals and groups are working to address the fears and concerns of people who have been medically underserved to help build confidence that vaccination is a safe way to end the pandemic.

Is the COVID-19 vaccine free?

The U.S. federal government is providing the vaccine free of charge to people living in the United States. However, the vaccination provider may charge an administration fee to your insurance, Medicaid, or Medicare. Vaccination providers can be reimbursed for this by the patient’s public or private insurance company or, for uninsured patients, by the Health Resources and Services Administration’s Provider Relief Fund. This is why you may be asked to bring your insurance card to your vaccine appointment. No one can be denied a vaccine if they are not insured, and no one should have to pay a vaccine administration fee out-of-pocket.

What if I don’t have a doctor or insurance?

Each U.S. state is responsible for how and when COVID-19 vaccines are given. Contact your state or local public health department about the vaccine distribution plan where you live. Vaccines are being given in doctors’ offices, retail pharmacies, hospitals, community clinics, and public health departments. Use this tool from the U.S. Centers for Disease Control and Prevention (CDC) to find more information about how to get vaccinated in your area.

COVID-19 Vaccines and People With Cancer
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