People living with cancer and their loved ones must constantly reassess their condition in relation to COVID-19 and its onslaught of risks, safety measures, and precautions — and most recently, vaccines.
Gayathri Nagaraj, an oncologist at the Loma Linda University Cancer Center in Loma Linda, California, United States, breaks down what is known about the approved mRNA vaccines currently available and what they could mean for cancer patients weighing their options.
Nagaraj says that mRNA-based vaccines developed by Pfizer-BioNTech and Moderna contain genetic material that signals the body to make copies of the virus’s spike protein, which then triggers the body’s immune system to react as if it were fighting against the virus itself. The immune system response the body has learned will help protect the person if they were to be exposed to the virus in the future. Rest assured, she says, the mRNA vaccines do not alter DNA or contain the live virus, and there is no risk of developing an infection from the vaccine.
In fact, she said, the technique used in mRNA vaccines was initially studied as a form of therapy to fight cancer. Professional cancer organizations and experts in the field — Nagaraj included — recommend mRNA vaccines for cancer patients and cancer survivors. The timing of the vaccine with regard to cancer treatment, however, should be discussed with the patient's oncologist first, she says.
The currently approved mRNA vaccines are safe for cancer patients so long as patients do not have any contraindications, according to the U.S. Centers for Disease Control and Prevention (CDC). Contraindications, or conditions that make a particular procedure inadvisable for the mRNA vaccine, include having a severe or immediate allergic reaction (such as anaphylaxis) after a dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG]).
Because many cancer patients are immunocompromised from treatments for their cancer, they form a vulnerable population at higher risk for developing severe symptoms and even death from COVID-19 infection, Nagaraj says. Based on this knowledge, professional organizations such as the American Association for Cancer Research (AACR) and National Comprehensive Cancer Network (NCCN) have recommended that patients with cancer receive priority access to vaccines.
Nagaraj joins other cancer experts in recommending that cancer patients undergoing active therapy may still receive the mRNA vaccine with the understanding that limited safety and efficacy data is available on these patients. She says it’s possible that some cancer patients may have decreased immune responses to the vaccine. In other words, patients with weakened immune systems may not mount the same response as a person whose immune system is intact and operating at full capacity.
Experts’ recommendations remain firmly in favor of cancer patients obtaining the vaccinations. The level of immunity the vaccine offers will still be important to reduce the risk of severe COVID-19 infections, Nagaraj says.
When it comes to side effects from the vaccine, she says, they resolve within a matter of days and signal a desired immune response. Physicians should monitor cancer patients already experiencing symptoms as part of their cancer or treatment for any additional side effects that they may experience after vaccination, Nagaraj says.
Both vaccines have received emergency use authorization (EUA) from the U.S. Food and Drug Administration (FDA) and proven more than 90 percent effective for those who have received both doses. Nagaraj says it is important to remember that patients must receive two doses to reap the benefits. Ideally, they should have them within the recommended time intervals — three weeks between doses for Pfizer-BioNTech and four weeks for Moderna — though some grace period is allowed.
It is also important to acknowledge what is not yet known about the COVID-19 vaccines, Nagaraj says, such as whether they will prevent an individual from spreading the virus to others or how long the immunity to the virus after vaccination lasts. For these reasons, she says, continuing protective measures such as wearing a mask, social distancing, and washing hands are vital until further guidance is available following widespread vaccination use.
Ultimately, Nagaraj affirms, the vaccines are safe, and she recommends cancer patients and caregivers receive the mRNA vaccine while continuing other preventative measures. As additional vaccines become available, cancer experts, patients, caregivers, and loved ones will need to revisit precautions and considerations for vaccination.