COVID-19 Vaccine Effective for Cancer Patients | News Center

According to a national study of veterans diagnosed with cancer in the last decade, mRNA-based COVID-19 vaccines are effective in preventing infection in most cancer patients.

However, researchers found that some vaccinated patients, including those who received treatment to suppress the immune system within 6 months prior to vaccination, were more likely to be infected with COVID-19 during the study than others. I found that it was not protected.

“In general, we know that cancer patients with COVID-19 have poor outcomes,” said Postdoc. Julie Tuyu Wu, MD, PhD. “Our goal is to identify patients who may benefit from additional interventions such as vaccine booster shots or who are candidates after exposure to prophylactic interventions such as oral antivirals and monoclonal antibody therapy. However, the main finding of our study is that COVID-19 vaccination is an effective way to prevent infection in most cancer patients. “

Wu shares the lead author of the study, which will be published on December 2nd. JAMA Oncology, Jennifer La, PhD, Major Data Scientists Veterans Boston Healthcare System.. The lead author of this study is Dr. Albert Lynn, MD. VA Palo Alto Healthcare SystemNikhil Munshi, MD, VA Boston’s doctor, Harvard Medical School professor of medicine. Dr. Nathanael Fillmore, Deputy Director of VA Boston Collaborative Research Program Informatics Center and Medical Instructor at Harvard Medical School.

“This study highlights the strengths of the Department of Veterans Affairs medical system across the country,” Fillmore said. “Access to high-quality data from veterans across the country was important to enable a rigorous test emulation approach to the study.”

COVID-19 is dangerous for cancer patients

Many cancer patients infected with COVID-19 have poor outcomes, with an estimated mortality rate of 13% to 33%. However, because cancer patients were excluded from early vaccine trials, it is not clear whether or to what extent the mRNA-based COVID-19 vaccine will protect cancer patients.

The researchers studied medical records of more than 180,000 VA patients who received systemic or systemic treatment, including chemotherapy or hormone therapy, between August 2010 and May 2021. The median age of patients was 73.7 years, with 94% being male. Of these, approximately 113,000 were vaccinated with Pfizer BioN Tech and Moderna, one of the two mRNA-based vaccines approved by the Food and Drug Administration between December 15, 2020 and May 4, 2021. I did. COVID-19 was excluded from the study, as were people who received the adenovirus-based vaccine manufactured by Johnson & Johnson. )

COVID-19 vaccination is an effective way to prevent infection in most cancer patients.

For each day of the study period, researchers matched vaccinated patients with peers with similar unvaccinated medical histories and demographic backgrounds and compared COVID-19 infection rates for each pair. Did.

To calculate the efficacy of the vaccine, the researchers compared the number of COVID-19 diagnoses in the vaccinated and non-vaccinated groups. If 10 out of 100 unvaccinated people are infected with 1 in 100 vaccinated people, the vaccine will prevent the possibility of infection in 9 out of 10 people and the vaccine will be 90% effective. Become.

The effect depends on the timing

Overall, the researchers found that the vaccine was about 58% effective in preventing infection two weeks after the second dose. However, the vaccine was approximately 85% effective for people who completed their last cancer treatment more than 6 months before the first dose. The vaccine is approximately 63% effective among people who have completed cancer treatment 3-6 months before the first dose and 54% among those who have completed treatment within 3 months of the first dose. was. (The two vaccines were equally effective.)

Treatment of cancer throughout the body includes chemotherapy that can suppress the immune system and hormone therapy that is unlikely to do so. Among those who completed cancer treatment within 3 months of the first dose, the vaccine was approximately 57% effective in those who received chemotherapy. It was about 76% effective for those who received hormone therapy. (The vaccine has been found to be substantially less effective in a small subset of patients with certain types of blood cancer that may suppress the immune system.)

“This is the first study of cancer patients looking for clinically significant outcomes (documented infections) rather than surrogate markers such as antibody production levels,” Wu said. “Vaccines tend to be less effective in some subgroups, but we found that there was no reason to avoid vaccination.”

Summer Han, Stanford University, Assistant Professor of Neurosurgery and Biomedical Informatics, is a co-author of this study.

This research was supported by the National Institutes of Health (Grants P01-155258-07 and P50-100707), Veterans Research and Development Department, Department of Defense, and Stanford Cancer Institute Innovation Awards.