WEDNESDAY, Dec. 15, 2021 (HealthDay News) -- COVID-19 vaccination provides far less protection to people with multiple myeloma than to survivors of other types of cancer, new research shows.
The findings highlight the need for multiple myeloma patients â€œto be especially careful -- to take social distancing seriously and utilize masking -- even if theyâ€™ve been vaccinated,â€ said study senior author Dr. Nikhil Munshi, from the Jerome Lipper Multiple Myeloma Center at Dana-Farber Cancer Institute in Boston.
The new findings come from a follow-up to research recently published in JAMA Oncology, where COVID infection rates were assessed in nearly 60,000 vaccinated and unvaccinated cancer survivors who had not received a systemic cancer treatment such as chemotherapy or immunotherapy in the previous six months.
The new study compared 818 adults with multiple myeloma who had been vaccinated against COVID-19 with an equal number of unvaccinated patients who also had the blood cancer.
Also included were nearly 9,600 patients with a condition known as monoclonal gammopathy of undetermined significance (MGUS), which increases myeloma risk. Half were vaccinated, half unvaccinated.
Over two to 41 weeks of follow-up, the effectiveness of vaccination in preventing infection varied widely. After two doses, it was 5.6% in myeloma patients, and 27.2% in people with MGUS. This compares with 85% in cancer survivors not on treatment.
Vaccine effectiveness started to decline about six months after patients' second dose, the study found.
The myeloma patient findings were presented Sunday at a meeting of the American Society of Hematology in Atlanta. Research presented at meetings should be considered preliminary until published in a peer-reviewed journal.
Researchers said the lower effectiveness of vaccination in myeloma patients likely owes to both the disease itself and to its treatment. Both can weaken the immune system.
â€œWe found that, compared to patients who hadnâ€™t been treated in the last six months, the rate of breakthrough infections was 2.6%,â€ Munshi said in a Dana-Farber news release.
â€œFor patients who were treated within the last 90 days, that number goes up to 4-5%," he added. "And in patients treated with daratumumab [an immunotherapy agent], the number was 9%.â€
The American Cancer Society has more on multiple myeloma.
SOURCE: Dana-Farber Cancer Institute, news release, Dec. 11, 2021