Reasons for COVID-19 Vaccine Hesitancy in Patients With Blood Cancer Are Complex

March 19, 2021
Allison Inserro

A survey released this month of US patients with blood cancers shows a somewhat surprising level of hesitancy about receiving a COVID-19 vaccine, but because patients with cancer were not included in clinical trials, the situation for this population is somewhat nuanced.

About 30% of patients with blood cancer are hesitant about receiving a COVID-19 vaccine, and those who are reluctant are also less likely to engage in self-protective behavior, according to a recent survey. The nationwide survey of more than 6500 individuals found that only about half said they were “very likely” to get vaccinated, and 1 in 3 were unlikely or unsure about it.

The findings also hew closely to other surveys looking at issues with vaccine hesitancy. For example, more general surveys have found that those living in rural areas have less interest in COVID-19 vaccination.

The survey is the product of The Leukemia & Lymphoma Society (LLS), Boston University Questrom School of Business, and The Behaviouralist, a London-based research consultancy

The findings are alarming given that patients with leukemia and lymphoma are more likely than patients with other cancers to get seriously ill or die from COVID-19, said Gwen Nichols, MD, chief medical officer of LLS, in an interview with The American Journal of Managed Care®.

“Blood cancer patients in particular have an increased rate of not only severe infection, but of death, compared to age-matched controls, and when they get COVID. And so it's incredibly important, especially for patients who are undergoing immunosuppressive therapy to be adequately protected,” she said.

The patient responses reflect the complexity of feelings about the issue given their individual circumstances.

Because the trials did not include oncology patients, physicians can’t give a straightforward answer about efficacy and safety, she said.

“We feel pretty comfortable about saying it will be safe for most patients, but obviously, each patient as an individual needs to talk to their doctor,” Nichols added. ”But the question of efficacy is a real one, and patients are responding to that, because they're concerned that they'll get side effects from the vaccine and no benefit."

The survey was conducted during the first 3 weeks of December 2020; on December 18, the FDA granted emergency use authorization for the Moderna vaccine, a week after the EUA for the Pfizer–BioNTech vaccine.

Respondents came from the LLS database. Of the 6516 respondents, 6 in 10 (59.8%) were female, 86% identified as White, 6.5% as Black or African American, and 4.7% as Hispanic. The average age was 64 years; most (70%) had an associate's degree or more.

Seventy percent said they are either very likely (50%) or likely (20%) to get vaccinated. The remaining 30% said they are very unlikely (8%), unlikely (9%), or neither likely nor unlikely to get vaccinated (13%).

Rural or suburban residents are also more likely—6.2 and 9.4 percentage points more, respectively—to be vaccine hesitant compared with city residents. This is in line with other surveys about attitudes toward COVID-19 vaccination; a survey released last month by the Kaiser Family Foundation found that 24% of rural adults do not want a vaccine.

Those who expressed hesitancy are also significantly less likely to take steps to prevent infection; the survey found that they are 3.8 percentage points less likely to say that they have worn a face mask and 1.6 percentage points more likely to say that they have taken no other protective measures.

LLS said the survey, which it plans to repeat, is the largest to date asking patients with cancer and survivors about their attitudes toward COVID-19 vaccines. It is also asking patients to join its patient registry to answer questions about their experience with COVID-19 vaccines.

Although scientists are not exactly sure why those with hematologic cancers have worse outcomes than other patients with cancer if they contract COVID-19, the general belief is that compromised immunity, in the form of B-cell depletion and fewer CD8+ T cells, is the culprit. Plus, there is another reason, Nichols said.

“The malignancy itself causes the immune system to be suppressed because you aren't making enough of your normal lymphocytes, because of the cancer clone. But the second half is the treatments that we give hit the same cells in order to kill them. They aren't completely selective, and so they hit the normal B lymphocytes as well,” she said.

From previous vaccines, she said, they know that patients on immunosuppressive treatments, who have undergone a bone marrow transplant or, more currently, have had chimeric antigen receptor T-cell therapy have a weakened immune response due to a lack of functioning lymphocytes to make those antibodies.

As more states end mask mandates and social distancing measures even as the level of infection nationwide remains high, it is especially important for family members of patients, who may not be able to get vaccinated due to active treatment, to get immunized and to continue wearing a mask and take precautions, Nichols said.

“It’s caregivers and family members [who] also need to be equally careful. For the sake of their blood cancer patient, it may even be more important that the healthy people around the patient get vaccinated,” Nichols said.