Covid-19 vaccination associated with low Covid infection in cancer patients

Cancer patients are at a greater risk of severe COVID-19 infection, although it is uncertain if SARS-CoV-2 vaccine is useful for them.

According to a new study, COVID-19 immunization was related to decreased SARS-CoV-2 infection rates in cancer patients. This study was conducted by Julie Tsu-Yu Wu and team, results of which were published in the JAMA Oncology.

The goal of this study was to see if there was a link between SARS-CoV-2 vaccination and SARS-CoV-2 infections in a group of cancer patients from the Veterans Administration (VA). From December 15, 2020, to May 4, 2021, this was a retrospective, multicenter, countrywide cohort study of SARS-CoV-2 immunization and infection among patients in the VA health care system. All people with solid tumours or hematologic malignancies who had systemic cancer-directed treatment between August 15, 2010, and May 4, 2021, and who were alive and without a recorded SARS-CoV-2 positive result on December 15, 2020, were eligible for inclusion. From December 15, 2020 to May 4, 2021, newly vaccinated patients were matched 1:1 with unvaccinated or not yet vaccinated controls based on age, race and ethnicity, VA institution, rurality of home address, cancer kind, and treatment type/timing. The primary assessment was confirmed SARS-CoV-2 infection. The risk ratio of SARS-CoV-2 infection for vaccinated persons relative to unvaccinated controls was used as a proxy for vaccination efficacy.

The findings of this study were:

1. A total of 184 485 patients met the eligibility requirements, with 113 796 receiving vaccinations. 29 152 vaccinated patients were matched 1:1 with unvaccinated or not yet vaccinated controls.

2. In the matched group, 436 SARS-CoV-2 infections were found after a median of 47 days of follow-up. In the vaccinated group, there were 17 COVID-19–related fatalities compared to 27 COVID-19–related deaths in the unvaccinated group.

3. Starting 14 days following the second dosage, the overall vaccination efficacy in the matched cohort was 58%.

4. Patients who received chemotherapy within three months of the first vaccination dose had a vaccine effectiveness of 57% beginning 14 days after the second dose, compared to 76% for those receiving endocrine therapy and 85% for those who had not received systemic therapy for at least six months prior.

In conclusion, the findings imply that SARS-CoV-2 immunization is related with decreased infection rates in cancer patients, particularly those who are not getting current systemic medication and those who are undergoing hormone treatment. Additional trials with a diverse patient group and a longer follow-up period, as well as research to determine the appropriate immunization schedule and delivery in relation to cancer and therapy type, will be beneficial.

Reference:

Wu JT, La J, Branch-Elliman W, et al. Association of COVID-19 Vaccination With SARS-CoV-2 Infection in Patients With Cancer: A US Nationwide Veterans Affairs Study. JAMA Oncol. Published online December 02, 2021. doi:10.1001/jamaoncol.2021.5771