Population-scale study highlights persistent risk of COVID-19 infection in some cancer patients despite vaccination

A study led by the universities of Oxford, Birmingham and Southampton and the UK Health Agency (UKHSA), published in Lancet oncology Today, the British Coronavirus Cancer Assessment Project found that while vaccination against COVID-19 is effective for most cancer patients, the level of protection against COVID-19 infection, hospitalization and death offered by the vaccine is lower than among the general population and the vaccine as a whole. . efficiency decreases faster.

Dr Leonard Lee of the Department of Oncology at Oxford University, who led the study, said: “We know that people with cancer have a higher risk of severe COVID-19 disease and that immune response y cancer patients after vaccination against COVID-19 below. However, no study was considered vaccine efficacy and its reduction in cancer patients at the population level. We conducted the largest real-world assessment of COVID-19 in cancer patients worldwide. ”

This study analyzed 377,194 people with active or newly diagnosed cancer who received two doses of the COVID-19 vaccine and underwent PCR testing for SARS-CoV-2 in England. The number of breakthrough COVID-19 infections and hospitalizations and deaths associated with COVID-19 in this cohort of cancer patients was compared with the control population without active or recent cancer.

Overall efficacy of COVID-19’s vaccine against infection population as a whole after two doses of COVID-19 vaccine during the study period was 69.8%, whereas in the cohort of cancers the overall efficacy of the vaccine was slightly lower (65.5%). This suggests that vaccination against COVID-19 is effective in most cancer patients. However, the effectiveness of the vaccine decreases faster in cancer patients. 3–6 months after the second dose of the vaccine, vaccine efficacy decreased by almost a third from 61.4% in the general population to 47.0% in the cancer cohort.

Although the vaccine provides higher protection against hospitalization associated with COVID-19 (83.3%) and death (93.4%) than against breakthrough infections in a cancer cohort, this protection also decreased by 3–3. 6 months after the second dose of vaccine.

Looking at the differences between people with different types of cancer, the effectiveness of the vaccine is lowest and weakens most rapidly in those who have blood cancer, lymphoma and leukemia.

The type of treatment people receive with cancer also affects both the overall effectiveness of the vaccine and its reduction. In cancer patients who have been treated with chemotherapy or radiation therapy for the past 12 months, the effectiveness of the vaccine is lower and decreases by 3-6 months more than in cancer patients who did not receive these treatments or were treated more than a year ago.

Professor Peter Johnson, a professor of medical oncology at the University of Southampton, commented: “This study shows that for some people with cancer, vaccination against COVID-19 may provide less effective and longer-lasting protection. 19 for people undergoing cancer treatment. ”

Helen Rowntree, Director of Research, Services and Interactions at Blood Cancer UK, said: “For our community COVID-19 has not disappeared and many people remain in their homes because of the threat of COVID-19 highlighted in this important study We know how important vaccines are to people with blood cancer. This study importantly shows that immunity weakens faster in people with blood cancer who are eligible for five vaccine doses, and we recommend that all blood cancer patients make sure they receive these doses. ”