Many people being treated for cancer are asking whether they should get one of the COVID-19 vaccines. Steven Pergam, M.D., of the Vaccine and Infectious Disease Division at the Fred Hutchinson Cancer Research Center in Seattle, was a co-leader of a committee formed by the National Comprehensive Cancer Network (NCCN) that recently released recommendations on COVID-19 vaccination in cancer patients. In this Q&A, Dr. Pergam discusses some of the questions people with cancer and cancer survivors have about these vaccines.

CDC, the NCCN recommendations, and other cancer-related organizations say that cancer patients are a high priority group for vaccination. Why?

We all want to get the vaccines to the people who are at most risk for severe COVID-19 complications, and the data show that cancer patients are high risk. Making highly efficacious vaccines available to those populations is going to be important to saving lives.

Are there any patients undergoing active cancer treatment who should not get vaccinated?

For patients who have just had a stem cell transplant or received CAR T-cell therapy, who are typically receiving immunosuppressive therapy, we recommend that they delay COVID-19 vaccination until at least 3 months after they’ve completed treatment. That’s based on data that [other] vaccines have had limited efficacy during periods when these patients are their most immunosuppressed.

The data are a little less clear for patients who are getting aggressive chemotherapy, but for those who are receiving more intensive treatment regimens—for example, those starting initial therapy for leukemia—we recommend that they delay vaccination until their cell counts recover.

Those are the two main groups where I think there is agreement that they should delay COVID-19 vaccination, at least initially.

And survivors, those not undergoing active cancer treatment. Are there any reasons they shouldn’t get vaccinated?

I think that depends on when you ask the question. How much vaccine do you have [available]? If you have unlimited amounts, then everybody should get vaccinated. But when you get into vaccine allocation issues, that’s when it gets challenging.

But there’s no question that many cancer survivors have immunologic deficiencies, so I see many of them as being at high risk. Cancer survivors are also people who tend to be older and have other comorbidities—heart disease, kidney or lung dysfunction—so they’re going to have other reasons that will put them at risk for developing severe COVID-19, and those are all reasons for them to get vaccinated.

And what about those who may be undergoing treatment soon, such as somebody just diagnosed with cancer or whose treatment has been delayed by the pandemic?

The approach we discussed in the NCCN committee is that we really don’t want to create guidance that will prevent cancer patients from getting vaccinated. If you start trying to nuance it for the “right time,” it may mean that many patients won’t get the vaccine. So, the best approach is to get the vaccine when you can.

Still, there are some caveats. We do recommend delays for patients undergoing stem cell transplant and those getting induction therapy for leukemia. In addition, cancer patients who are about to undergo surgery should probably wait for a week until after surgery to get vaccinated. Because we don’t want any potential side effects from the vaccine—for example, a fever—to potentially delay their surgery.

So, there are some specific callouts, but we tried to limit restrictions.

Are researchers collecting data on how effective the vaccines are in people with cancer?

There are a number of research groups interested in vaccine efficacy in patients who have had bone marrow transplants, and there are groups looking at people who have blood cancers, like CLL or CML, because they are more likely to have immunodeficiency over a long period of time. Everyone wants to know the answer to the question: How do they respond to these vaccines?

There will be lots of analyses that will need to be done. I want to see studies of how well the vaccines work in people with specific cancers, as well as in those who receive specific chemotherapies or treatment regimens.

Is there any indication that current patients or survivors will have less protection from a COVID-19 vaccine?

Based on the data from other vaccines, I think it’s highly likely that it’s not going to be the 95% protection we’re seeing against symptomatic COVID-19 [from the Pfizer and Moderna vaccines] in the general public. I think it will be less than that. But even if it’s 50%, it’s still going to be a major benefit.

And similar to the flu vaccine, preventing infection is not the only aim, it’s also preventing the complications of infection. These COVID-19 vaccines may not prevent the primary infection, but we hope that they can prevent cancer patients from developing COVID-19 symptoms or being hospitalized, as has been seen in the phase 3 trials among the general public. There could be other downstream benefits that could be very helpful.

What about caregivers of those with cancer? Should they be a priority group for vaccination?

This is an underappreciated question. There’s no doubt that if you think about a vaccine strategy, if we assume that people with cancer aren’t going to respond as well to the COVID-19 vaccine, one of the best ways to protect them is to give the vaccine to people who will respond well. And that means anybody who they spend time with. So, anybody who is a caregiver, a loved one, or is in close contact with somebody with cancer, it’s important for them to get vaccinated.

Because the thought is that, first, it will decrease the caregiver’s risk of developing symptomatic infections and data suggest that symptomatic people are more likely to transmit the virus to people around them.

And, two, we hope that available vaccines may prevent transmission—although available studies evaluating this question are ongoing. If that’s true, then caregivers and loved ones getting vaccinated will really help. Because that cocooning effect, vaccinating the close contacts around people with cancer, can provide extra protection.

Is there any indication that people with cancer/cancer survivors are choosing not to get vaccinated?

That’s hard to know right now. Cancer patients are just starting to get these vaccines, due to challenges in the supply chain. I think some cancer patients will be hesitant, but not necessarily more so than the general population. We hope that they are more accepting of vaccines because they know they’re at risk [of severe COVID].

I can say that locally, in [Seattle-area] institutions, cancer patients are clamoring to get the vaccine. Physicians are feeling challenged because they’re getting so many calls from their patients to ask when it will be available and when can they get it. The patients know the risk, and they see it as an opportunity to protect themselves. That’s great to see. And I hope it continues. 

How do you see the approach to vaccination changing over the coming months?

One thing for people to be aware of is that the guidance around the COVID-19 vaccines is going to change over time. And that’s for a couple of reasons. One, because more data will become available. Even if they’re small studies, they can be very informative. Two, there are going to be more vaccines, the Johnson & Johnson and AstraZeneca adenovirus vector vaccines may soon be available for the public.... And there are the protein-subunit vaccines, like the one currently in trials from Novavax.

We expect that other vaccines will allow more people to get vaccinated. But there may be one or two vaccines that will be better for cancer patients, so we’ll need to see more data.

I really want to see NCI and NIH and other funding agencies support these types of studies. It is critical to choose the vaccines with the highest efficacy in cancer patients and to help us decide who should be vaccinated and when. We’re just beginning to think about trials that can be pragmatic and useful for providers—to best understand how to protect patients. That is going to be very important as we continue to address the pandemic and protect patients against SARS-CoV-2 in the future.

This post was originally published on February 10, 2021 by the National Cancer Institute. It is republished with permission.