It is known that patients with cancer have a higher risk of developing severe COVID-19 disease and that the immune response in cancer patients following vaccination is lower. But no study had examined short-and long-term vaccine effectiveness and protection level after two doses of COVID-19 vaccine in cancer patients at real world population level. A large population-based study from the UK, which was co-led by the Universities of Oxford, Birmingham and Southampton and the UK Health Security Agency, and that was recently published in The Lancet, indicates that cancer patients receive a lower level of protection from the vaccines, and that this protection wears off faster than it does in the general population.
The study shows vaccine protection is significantly lower in cancer patients compared to the general population, particularly in the subgroups of patients with lymphoma or leukaemia, and those with a recent cancer diagnosis receiving systemic anti-cancer or radiotherapy treatments within the past one year. Furthermore, the study highlights the importance of continuing vaccination booster programmes for all cancer patients – especially for patients with haematological cancers – and rapid access to COVID-19 treatments for patients developing symptomatic COVID infection due to waning vaccine protection.
For this population-based test-negative case-control study of the UK Coronavirus Cancer Evaluation Project (UKCCEP), scientists extracted data from the UKCCEP registry on all SARS-CoV-2 PCR test results, vaccination records, patient demographics, and cancer records from England, UK, from 8 December 2020, to 15 October 2021.
Adults with cancer in the UKCCEP registry were identified via Public Health England’s Rapid Cancer Registration Dataset between 1 January 2018, and 30 April 2021, and comprised the cancer cohort. A control population cohort was constructed from adults with PCR tests in the UKCCEP registry who were not contained within the Rapid Cancer Registration Dataset. The coprimary endpoints were overall vaccine effectiveness against breakthrough infections after the second dose (positive PCR COVID-19 test) and vaccine effectiveness against breakthrough infections at 3–6 months after the second dose in the cancer cohort and control population.
The cancer cohort comprised 377,194 individuals, of whom 42,882 had contracted breakthrough SARS-CoV-2 infections. The control population consisted of 28,010,955 individuals, of whom 5,748,708 had contracted SARS-CoV-2 breakthrough infections. Overall vaccine effectiveness was 69.8% (95% CI: 69.8–69.9) in the control population and 65.5% (95%CI: 65.1–65.9) in the cancer cohort. Vaccine effectiveness at 3–6 months was lower in the cancer cohort (47.0%, 46.3–47.6) than in the control population (61.4%, 61.4–61.5). The worst outcomes were observed in cancer patients with lymphoma (12.8% effectiveness) and leukaemia (18.5% effectiveness).
Lead author Professor Siow Ming Lee, Consultant Medical Oncologist at UCLH: “Our study offers some reassurance around the fact that COVID-19 vaccination does provide protection for most cancer patients. But it also highlights the need for vulnerable cancer patients to be prioritised for booster vaccinations, and COVID-19 prophylaxis when indicated, most importantly for lymphoma or leukaemia patients due to their rapidly waning vaccine effectiveness, and the importance of quick access to other COVID-19 treatments for cancer patients if they develop symptomatic infection, given the fact that their vaccine protection wanes more quickly overall than general population.”
Lee LYW, Starkey T, Ionescu MC, et al. Vaccine effectiveness against COVID-19 breakthrough infections in patients with cancer (UKCCEP): a population-based test-negative case-control study. Lancet Oncol. 2022 May 18;23(6):748–57.