Malcolm Rhodes(National COVID antibody survey charity/supporters team) and Thomas Starkey(UK COVID/Cancer Clinical Lead)-Editorial
Cancer patients should receive COVID vaccines but may be at more risk from COVID than those without cancer. In addition to vaccines they should also receive:
- Testing to determine their risk
- More frequent vaccine boosters
- Preventive treatments and
- Rapid access to anti-virals if they are infected by COVID
These approaches should to keep them as safe as possible.
When the first COVID vaccines were first tested, they were found to be remarkably effective and were rolled out around the world. However, people with cancer were not included in the trials and it was not clear how effective vaccines would be for them.
It was already known that some people with cancer are more likely to have infections, and vaccines such as flu might not be as protective for them. This is due to a weaker immune system caused either by their treatment or by the disease itself. It was likely that cancer patients would also be more likely to catch COVID and the vaccines may be less effective for these people.
A huge new study has been done to find out if, after vaccination, cancer patients were infected more often by COVID than the general population. The results are now in (1).
The study found that after two doses of vaccine, more cancer patients were infected with the COVID virus (Delta strain) than people who did not have a cancer diagnosis.
The effectiveness of the vaccine also fell over time. The fall was faster in cancer patients than in the general population. This means that cancer patients will need booster shots sooner than most people.
People were more at risk of catching COVID during treatment, or up to a year after. The treatments that caused the greatest reduction in vaccine effectiveness were chemotherapies and Rituximab or similar treatments that suppress the immune system.
People with certain cancers were more at risk of catching COVID than others. People with slow growing (“indolent”) blood cancers such as lymphomas or leukaemias were not protected as much as others by COVID vaccines (1).
After three vaccine doses, called “boosters”, protection was greatly increased for most of the general population and most cancer patients, but some were still left with little protection (2). In particular, blood cancer patients often had lower protection compared with the general population.
The researchers also measured anti-COVID antibodies in the blood of the study participants. This showed that those cancer patients with the lowest antibody levels were also the most likely to become infected by the virus SARS-COV-2 and to need hospitalization (3). Again, blood cancer patients were those with the lowest antibody levels and the highest risk of infection. In particular lymphoma and leukemia patients had very low antibody levels (3). Myleoma patients were also at high risk of covid infection but had slightly higher antibody levels.
These results are consistent with the theory that some high-risk patients have low antibody protection after vaccination and would likely benefit from a preventive treatment of COVID antibodies to increase their antibody levels. Such treatments include Evusheld TM or, potentially, a treatment from the plasma purified from the blood of people who have been infected by SARS-COV-2 and generated high antibody levels. This is supported by the results of the PROVENT study (4).
The link between low levels of antibodies and reduced protection from COVID-19 infection and hospitalization by vaccines for different cancers is shown in the chart below:
(1) Lee et al. (2022). Vaccine effectiveness against COVID-19 breakthrough infections in patients with cancer (UKCCEP): a population-based test-negative case-control study. Lancet Oncology 23 (6), p748-757, https://doi.org/10.1016/S1470-2045(22)00202-9
(2) Lee et al. (2022). COVID-19: Third dose booster vaccine effectiveness against breakthrough coronavirus infection, hospitalisations and death in patients with cancer: A population-based study. European Journal of Cancer 175, p1-10, https://doi.org/10.1016/j.ejca.2022.06.038
(3) Lee et al. (2022). Association of SARS-CoV-2 Spike Protein Antibody Vaccine Response With Infection Severity in Patients With Cancer: A National COVID Cancer Cross-sectional Evaluation. JAMA Oncology, pE1-E9, https://doi.org/10.1001/jamaoncol.2022.5974
(4) Covid-19: Evusheld is approved in UK for prophylaxis in immunocompromised people. British Medical Journal,BMJ 2022;376:o722, http://dx.doi.org/10.1136/bmj.o722