Research suggests that delaying second COVID vaccine does leave cancer patients vulnerable to virus

29 March 2021

Data from the world’s first reported trial to examine the level of immune protection after the Pfizer-BioNTech vaccine in cancer patients has found that anti-SARS-CoV-2 antibody responses at week 3 following the first dose of the vaccine were only 39% and 13% in the solid and haematological cancers, compared to 97% in those without cancer.

The pre-print study also reports that when the second dose of the vaccine was given three weeks after the first dose, the immune response improved significantly for solid cancer patients with 95% of them showing detectable antibodies to the SARS-CoV-2 virus within just two weeks. By contrast, those who did not get a vaccine boost at three weeks did not see any real improvement, with only 43% of solid cancer patients and 8% of blood cancer patients developing antibodies to the Pfizer vaccine at five weeks compared to 100% of healthy controls.

Interim results of the safety and immune-efficacy of 1 versus 2 doses of COVID-19 vaccine BNT162b2 for cancer patients in the context of the UK vaccine priority guidelines