COVID, Vaccines and Cancer 2022

Malcolm Rhodes-Editorial (National COVID antibody survey charity/supporters team)

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

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 in1.

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 vaccines1.

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 protection2.  In particular, blood cancer patients often had lower protection compared with the general population.

References

(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

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