• Most people with leukemia are recommended to receive the COVID-19 vaccine as soon as it is made available to them.
• Although some leukemia treatments may reduce the effectiveness of the COVID-19 vaccine to a degree, it will still provide important protection from the coronavirus.
• Those taking corticosteroid medications or other treatments that lower white blood cell counts should consider discussing the timing of their COVID-19 vaccines with their health care providers.
• People recovering from stem cell transplants or CAR-T cell therapy are recommended to wait until their immune systems have improved to maximize the vaccine’s effectiveness.

Ever since the U.S. Food and Drug Administration (FDA) approved the Pfizer-BioNTech and Moderna COVID-19 vaccines in December 2020, people living with leukemia have had questions about whether these inoculations are safe and effective for them.

In January 2021, the National Cancer Center Network (NCCN) issued recommendations stating that people with cancer, including those receiving active therapy, should receive the COVID-19 vaccine as soon as it becomes available to them. Members of MyLeukemiaTeam still have many questions about the COVID-19 vaccines.

MyLeukemiaTeam invited Dr. Matt Kalaycio to help us address these questions. Dr. Kalaycio is a board-certified hematologist and a professor at the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University. Dr. Kalaycio sits on the board of directors for the NCCN.

The COVID-19 vaccines are so new that there is not yet any specific data on results or side effects in people with blood cancers. How can we know whether the vaccines are safe and effective for this population?

Both vaccines that are currently available in the United States were developed after going through rigorous, randomized clinical trials in tens of thousands of patients. There is no reason to think that there would be any additional safety risk in patients with cancer, over and above what the rest of the population experienced. We're confident and comfortable saying that there is no additional safety risk in patients with cancer compared to the general population, and that has been our experience to date.

The Pfizer-BioNTech and Moderna vaccines are both messenger RNA (mRNA) vaccines, a new type of vaccine. Do we know how mRNA vaccines might affect blood cancers or interact with chemotherapy or other medications used to treat cancer?

There is no reason to think that they would have any impact on outcomes in any patient, much less those with cancer or blood cancers. There is nothing alive in the vaccine. All the vaccine does is provide very small pieces of coronavirus, to which the antibodies against COVID-19 can be generated. The vaccine generates an immune response in us, and then the mRNA goes away. It should not interact with our RNA or DNA at all.

Is one vaccine or the other considered safer or more effective for people with blood cancer?

No. In my review of the available data, it appears to me that they are very similar in both their effectiveness and in their side effect profiles.

Does it matter whether someone is in remission or actively treating their blood cancer?

Not exactly. We are not sure because cancer patients were not included in the original studies. It is possible that treatment of a blood cancer could reduce the effectiveness of the vaccine, but that should have no impact on its safety.

Having said that, the NCCN has come up with guidelines that suggest vaccination for everyone with cancer, regardless of their timing of the treatment, with one exception: if the white blood cell count is low or expected to be low at the time of the vaccine. The reason for that exception is so that if a fever develops because of the vaccine, it is not misinterpreted as an infectious fever.

Do you recommend that blood cancer patients check with their doctors and have their white blood cell levels checked before receiving the vaccine, if possible?

It is generally true that patients who are getting cancer therapy should talk to their doctors before doing pretty much anything.

But no, I don't necessarily think everybody needs to have their white blood cell counts checked. However, if a patient is being treated with treatment that can affect the white blood cell count, it would be reasonable to check the white blood cell count prior to vaccination, or to simply wait out the time period until there's no longer any risk that white blood cells might be low.

For those who are undergoing a chemotherapy regimen, does the timing of the COVID-19 vaccine matter?

We're not sure, but we try to avoid the period of time in between chemo cycles when the white blood cell count is lowest due to the chemotherapy’s effect on the bone marrow. It might be best to get the vaccine closer to the actual time of the chemotherapy administration, rather than in the middle, between cycles. As long as the white blood cell count is not low, vaccines can be given.

Is it still safe to receive a COVID-19 vaccine if someone with blood cancer has undergone a stem cell transplant?

In patients who have had a stem cell transplant, their immune systems are incapable of reacting to a vaccine for at least three months following the actual transplant. We recommend delaying all vaccines for at least three months following an autologous [using one’s own stem cells] or allogeneic [using stem cells from a donor] stem cell transplant.

For those living with graft-versus-host disease after an allogeneic (or donor) stem cell transplant, is there any recommendation?

The effectiveness of a COVID-19 vaccine might not be as good in someone with graft-versus-host disease who’s on immunosuppressive treatment, compared to someone who's perfectly healthy. But that doesn't mean they shouldn't get the vaccine — some protection is better than no protection. Therefore, we recommend the vaccine.

For those undergoing radiation, is there any concern about getting the COVID-19 vaccines? Is timing important?

No. Radiation is generally given to a specific area, and is therefore not likely to impact blood counts. The only exception is total body irradiation administered as part of a stem cell transplant, which can affect blood cell counts. The same recommendations that apply with a stem cell transplant would apply to that radiation.

Some people with blood cancers receive intravenous immunoglobulin, or IVig, infusions to manage their symptoms. Others receive blood or blood product transfusions. Should COVID-19 vaccines be timed around these types of treatments?

No, the timing of those treatments will have no impact with regard to the effectiveness or safety of the vaccine.

Are there any specific therapies or classes of medications used in blood cancers that may cause interactions or impact the effectiveness of the vaccination?

Corticosteroids (Steroids)

Steroids, such as prednisone and dexamethasone, can reduce the effectiveness of the vaccine. That doesn't mean you shouldn't get the vaccine, but it would be reasonable to speak with your physician to optimize the timing of the vaccine.

Tyrosine Kinase Inhibitors and Bruton's Tyrosine Kinase Inhibitors

There is no contraindication for people taking drugs like Gleevec (imatinib) and other tyrosine kinase inhibitors. These medications have very little impact on the immune system. The Bruton's tyrosine kinase inhibitors like Imbruvica (ibrutinib) can affect the immune system and reduce the effectiveness of the vaccine. It has nothing to do with safety, only about whether or not it will work as well as it would in someone who's not on those drugs.

We still recommend vaccinations — they're still going to have some degree of protection. Because those medications are taken every day, it doesn't matter when you get the vaccine.

Biologics (Monoclonal Antibodies)

We know that patients who are getting drugs like Rituxan (rituximab), Gazyva (obinutuzumab), and other anti-B cell antibodies can develop higher-risk COVID-19 disease because their immune systems simply can't create the antibodies necessary to get rid of the virus. The NCCN guidance and our own institutional guidance is to go ahead and get the vaccine as soon as possible. The sooner the better, because getting COVID-19 in that situation could be devastating and potentially fatal.

Having said that, there is controversy about the timing of that vaccine. We do not know the best timing for patients who are getting antibodies. Some experts recommend waiting up to six months, and there are others who say we need to give it right away.

CAR-T Cell Therapy

Experts disagree about the exact timing, but we generally recommend waiting for three months following a CAR-T cell infusion. We try to wait until we're confident that the immune system can respond to the vaccination.

The currently approved COVID-19 vaccines both require two doses, timed 21 days after the first for the Pfizer-BioNTech vaccine and 28 days later for the Moderna vaccine. Is it important to get the second dose for the vaccine to be effective?

We do believe that the second dose is important. We know that the second dose is important in increasing efficacy. We don’t know whether the exact timing is important. The current recommendations are that they should be given on time. That's the way the trials were done.

Some MyLeukemiaTeam members have expressed worry about the fast-tracked development of the COVID-19 vaccines. Do you have any concerns about the speed or nature of how the vaccines were developed? And if not, why not?

We should be thankful that the technology existed when the pandemic started. Had we not had the technology available, we'd still be waiting for a vaccine, we'd still be in the middle of the winter surge, and more people would be dying. Yes, it happened quickly, but it happened quickly because the technology was there to take advantage of.

The important part is that the studies on which these vaccinations were approved were randomized and placebo-controlled — the gold standard of evidence. The speed with which it happened is not what people should be concerned with. What matters is what happened in the randomized trials, and there were no safety concerns other than very rare allergic reactions.

Given the recent introduction of the COVID-19 vaccines, there is no data available yet about potential long-term side effects. Are you concerned about long-term side effects from the vaccines?

No, not really. Of all the vaccines that are out there, long-term consequences of vaccines are unheard of. They just don't happen.

On the other hand, it's 2021, and we've got the technology to follow all the patients who are getting vaccinated for adverse events. This will be different from the vaccines of the past, which we didn't really follow for any length of time.

Many members state that they would rather wait until more is known about the vaccine’s side effects. Is there any benefit to waiting until later to receive the COVID-19 vaccines, in your opinion?

I wish I knew the answer to that for sure, but I don't. There is some potential benefit if you feel more reassured. But everything I'm saying about the vaccine today is almost certainly going to be true six months from now.

The problem with waiting is that the patient remains at risk for COVID-19. Patients with blood cancers, and cancer in general, have almost twice as much risk for hospitalization and severe COVID-19 than the general population has. That's why physicians like me are recommending vaccination sooner rather than waiting.

If someone has had a bad reaction to the flu vaccine in the past, is that an indication they might have a bad reaction to the COVID-19 vaccine?

Not at all. They're completely different. There's one situation where prior allergy can be a reason to not get the vaccine — an anaphylaxis reaction to pegylated or peg-based polyethylene glycol. That same component is in these vaccines, and those few people should not be exposed to the vaccine without some desensitization. Other than that, prior history of reactions to vaccines doesn’t matter.

What would you say to those who are nervous and reluctant to get the COVID-19 vaccine?

We are facing a pandemic of almost biblical proportions. With virus variants coming up all the time, the faster we get this under control, the more lives we shall save. The only way we are ever going to get it under control is with mass vaccination — I mean everybody.

Although I understand the hesitant feelings, I implore everyone listening to me who remains hesitant to talk to trusted sources and learn more. Many of those fears are misplaced. We can actually save lives and get out of this mess if vaccines are part of the prescription.

Light at the End of the Tunnel

Some MyLeukemiaTeam members have already received the COVID-19 vaccine, while others are still waiting for access or are considering their options.

When one member asked whether others were planning to get vaccinated against COVID-19, another responded, “Heck yes! Never pass up an opportunity to add another layer of shield in a very dangerous situation! My immune system is very low, but I got my first Pfizer shot on Wednesday without any discomfort at all!” A different MyLeukemiaTeam member wrote, “I am three weeks out of having both shots and feeling good.”

Some members shared how getting the vaccine has improved their mood. “I got my first COVID vaccine shot today. Light at the end of the tunnel!” wrote one MyLeukemiaTeam member. Another said, “I'm just so happy that tomorrow I am receiving my first dose of the COVID-19 vaccine.” Another stated, “I'm actually looking forward to it and the peace of mind it will give me.”

Many members view the COVID-19 vaccines as a key step in returning to normal life. Some have shared what they are looking forward to most after getting vaccinated. “I can't wait to get it. I want to go to church. I've not been able to go for about three months,” shared one MyLeukemiaTeam member. Another wrote, “I get my second COVID vaccine on Thursday, so in three weeks, I can go to see my daughter and my new grandson. I feel very blessed!”

Talk With Others Who Understand

MyLeukemiaTeam is the social network for people with leukemia and their loved ones. On MyLeukemiaTeam, more than 7,600 members come together to ask questions, give advice, and share their stories with others who understand life with leukemia.

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