The COVID Vaccine’s Effectiveness for Cancer Patients: 3 Key Takeaways from the European Society for Medical Oncology Conference

Published Sep 22, 2021

Sydney Schaefer

New Vaccination Research

  • Since the life-saving COVID-19 vaccine was first introduced to the world last year, cancer patients have wondered how well the vaccine can work for them. Studies presented at an oncological conference in Europe indicate that the cancer patients reap benefits from the vaccine and the booster.
  • One study found “adequate” levels of coronavirus antibodies in the blood of cancer patients after vaccination, even those who were being treated with chemotherapy and immunotherapy.
  • Dr. Nina Shah, a hematologist at the University of California San Francisco, told SurvivorNet previously that it’s critical that cancer patients going through active treatment get the booster shot.

Since the life-saving COVID-19 vaccine was first introduced to the world last year, cancer patients have wondered how well the vaccine can work for them.

Cancer patients weren’t included in the clinical trials conducted to test the vaccine, leaving many questions unclear. Is the vaccine safe for cancer patients? Can the vaccine provide adequate protection against severe forms of COVID-19 to people with immune systems weakened by anti-cancer medicines?

There was much discussion on this topic at the annual European Society for Medical Oncology conference, or ESMO Congress 2021, the leading professional society for medical oncology, and it was revealed, through multiple studies, that cancer patients have “an appropriate, protective immune response to vaccination without experiencing any more side-effects than the general population.”

Related: Adolescent and Young Adult Cancer Survivors Are Reluctant to Get the COVID-19 Vaccine; What Survivors Need to Know About the Vaccine

The findings discussed at the conference “offer conclusive evidence that while being largely effective, anti-COVID vaccination is just as safe for people with cancer as it is for the general population,” according to Dr. Luis Castelo-Branco, a medical oncologist in the ESMO Scientific and Medical Division.

This drives home the message that oncologists have expressed to SurvivorNet: Cancer patients should get the vaccine. This is further underscored by the fact that cancer patients may have a weakened immune system, especially if they are going through chemotherapy treatments. This makes cancer patients more vulnerable to COVID-19, hence the importance of getting the shots.

In a previous interview, Dr. Vincent Rajkumar, a medical oncologist at the Mayo Clinic in Rochester, Minn., tells SurvivorNet that the vaccine is “very safe,” adding that there’s “no increased risk to you just because you have cancer.”

Here’s what cancer patients need to know about the key takeaways from three studies on this topic presented at ESMO Congress 2021:

5 COVID-19 Vaccine Questions Answered by Expert Physician

High Rate of Vaccine Efficacy for Cancer Patients

Two studies presented at the conference concluded that cancer patients vaccinated against the virus are, in fact, protected in some capacity, regardless of what anti-cancer medicines they are taking. The studies also addressed the importance of getting both vaccine doses. (The Johnson & Johnson one-dose vaccine was not discussed.)

Study 1: The study, published in Annals of Oncology, a peer-reviewed medical journal of oncology, surveyed 791 patients from different hospitals in the Netherlands. The participants were split into four groups: people without cancer, cancer patients treated with immunotherapy, patients treated with chemotherapy and patients treated with a chemo-immunotherapy combination; participants with cancer had solid tumor cancers. The purpose of the study was to measure their responses to the Moderna two-dose COVID-19 vaccine.

The study found that 28 days after the second vaccine dose was administered, “adequate” levels of coronavirus antibodies in the blood were found in 84% of patients with cancer receiving chemotherapy, 89% of patients receiving chemo-immunotherapy in combination and 93% of patients on just immunotherapy.

Study 2: The same conclusion was met in a second study that examined the effects of tozinameran (Pfizer-BioNTech) among 232 cancer patients and 261 control subjects in Israel; while less than a third of people with cancer (29%) developed antibodies after receiving the first dose, compared to 84% in the control group, this proportion increased to 86% following administration of the second dose.

Dr. Antonio Passaro, ESMO press officer and a lung cancer expert, used these studies as examples to make an important point: Cancer patients need to have complete, two-dose vaccinations so they can develop enough protective antibodies against the novel coronavirus.

COVID-19 Booster Shots Increase Efficacy for More Cancer Patients

In a previous interview with SurvivorNet, Dr. Nina Shah, a hematologist at the University of California San Francisco, says it’s critical that cancer patients going through active treatment get the booster shot, “since we know some cancer patients do not mount a sufficient immune response after the first series of shots.” Her message is backed by additional research presented on this topic at the European conference.

Related: Can Cancer Patients Get a COVID-19 Vaccine Booster Shot?

Study 3: Out of 585 cancer patients with both solid tumor cancers and hematologic (blood) cancers having received two doses of either the tozinameran (Pfizer-BioNTech) or AstraZeneca COVID-19 vaccine in the United Kingdom, those patients who have hematologic cancers didn’t respond as well to the vaccine as those with solid tumor cancers. Because of this, it’s recommended that all cancer patients, regardless of their type, get a COVID-19 vaccine booster shot. (The AstraZeneca vaccine is not available in the United States.)

“More data is needed to better understand for whom and when these vaccination boosts should be considered, but in general it would make sense to prioritize all patients with compromised immune function, including patients with cancer,” Castelo-Branco says.

Related: COVID Vaccines Are Far Less Effective in Most Cancer Patients, Ineffective in Some, According to New Research

A study published last month that wasn’t presented as ESMO Congress 2021 further highlights this discrepancy in effectiveness; the study focused on 160 patients with hematologic cancers and found that only 39% of participants tested positive for COVID antibodies after receiving the vaccination.

“(O)ur findings raise a concern that patients with hematologic cancers, particularly those receiving B-cell-depleting immunotherapy, may not gain adequate protection from vaccination, and as observed in our cohort, may still develop a potentially fatal infection,” the study notes.

So, as Shah says, it’s critical that cancer patients get the COVID-19 vaccine and booster shot.

Related: People Who Are Immune-Suppressed and Get COVID-19 May Carry the Virus for More than Two Months

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Sydney Schaefer is a writer for SurvivorNet. Read More