though this population still suffers higher risks than those of the general population, according to a new large-scale observational study out of the United Kingdom.
People living with lymphoma and those who underwent recent systemic anti-cancer treatment or radiotherapy are at the highest risk, according to study author Lennard Y.W. Lee, PhD. “Our study is the largest evaluation of a coronavirus third dose vaccine booster effectiveness in people living with cancer in the world. For the first time we have quantified the benefits of boosters for COVID-19 in cancer patients,” said Dr. Lee, UK COVID Cancer program lead and a medical oncologist at the University of Oxford, England.
The research was published in the November issue of the European Journal of Cancer.
Despite the encouraging numbers, those with cancer continue to have a more than threefold increased risk of both hospitalization and death from coronavirus compared to the general population. “More needs to be done to reduce this excess risk, like prophylactic antibody therapies,” Dr. Lee said.
Third dose efficacy was lower among cancer patients who had been diagnosed within the past 12 months, as well as those with lymphoma, and those who had undergone systemic anti-cancer therapy or radiotherapy within the past 12 months.
The increased vulnerability among individuals with cancer is likely due to compromised immune systems. “Patients with cancer often have impaired B and T cell function and this study provides the largest global clinical study showing the definitive meaningful clinical impact of this,” Dr. Lee said. The greater risk among those with lymphoma likely traces to aberrant white cells or immunosuppressant regimens, he said.
“Vaccination probably should be used in combination with new forms of prevention and in Europe the strategy of using prophylactic antibodies is going to provide additional levels of protection,” Dr. Lee said.
Overall, the study reveals the challenges that cancer patients face in a pandemic that remains a critical health concern, one that can seriously affect quality of life. “Many are still shielding, unable to see family or hug loved ones. Furthermore, looking beyond the direct health risks, there is also the mental health impact. Shielding for nearly 3 years is very difficult. It is important to realize that behind this large-scale study, which is the biggest in the world, there are real people. The pandemic still goes on for them as they remain at higher risk from COVID-19 and we must be aware of the impact on them,” Dr. Lee said.
The study included data from the United Kingdom’s third dose booster vaccine program, representing 361,098 individuals who participated from December 2020 through December 2021. It also include results from all coronavirus tests conducted in the United Kingdom during that period. Among the participants, 97.8% got the Pfizer-BioNTech vaccine as a booster, while 1.5% received the Moderna vaccine. Overall, 8,371,139 individuals received a third dose booster, including 230,666 living with cancer. The researchers used a test-negative case-controlled analysis to estimate vaccine efficacy.
The booster shot had a 59.1% efficacy against breakthrough infections, 62.8% efficacy against symptomatic infections, 80.5% efficacy versus coronavirus hospitalization, and 94.5% efficacy against coronavirus death. Patients with solid tumors benefited from higher efficacy versus breakthrough infections 66.0% versus 53.2%) and symptomatic infections (69.6% versus 56.0%).
Patients with lymphoma experienced just a 10.5% efficacy of the primary dose vaccine versus breakthrough infections and 13.6% versus symptomatic infections, and this did not improve with a third dose. The benefit was greater for hospitalization (23.2%) and death (80.1%).
Despite the additional protection of a third dose, patients with cancer had a higher risk than the population control for coronavirus hospitalization (odds ratio, 3.38; P < .000001) and death (odds ratio, 3.01; P < .000001).
Dr. Lee has no relevant financial disclosures.