Two new studies were published in Magazine “Blood” Point out that COVID-19 mRNA vaccines such as Pfizer-BioNTech and Moderna may decrease Chronic Lymphocytic Leukemia (CLL) And multiple myeloma, two types of blood cancer. Researchers believe that these studies can help determine the ideal time to vaccinate these groups.
The first study reported that the immune response rate of CLL patients was significantly lower than COVID-19 mRNA vaccine Take two doses than healthy individuals of the same age. Since clinical trials of these vaccines do not include patients with high-risk blood cancers who suffer from serious diseases and virus-related complications, it is important to calibrate the effectiveness of the vaccine in this population.
In this study of 167 CLL patients, Four out of ten (39.5%) There is an antibody-mediated positive reaction to the vaccine; in contrast, all healthy adults (control group) elicit an immune response.
Interestingly, studies have shown that the immune response of CLL patients varies greatly, depending on how long they are in the cancer treatment process. For example, the vaccine response rate of patients receiving active cancer treatment is significantly lower than that of patients who have completed treatment and have remission. 16% and 79% respectively.
This Untreated patients (Those diseases that are under observation but not yet treated) have a response rate of 55.5%. Similarly, people who completed CLL treatment at least one year before vaccination had a significantly higher response to the vaccine than those who continued to receive treatment last year, at 94% and 50%, respectively.
“In general, the response rate of the vaccine is significantly lower than that observed in the general population. This is likely due to the existence of the cancer itself and Certain benefits of LLC”Said Dr. Yair Herishanu, the lead author of the study, associate professor of hematology, and head of LLC services at Sourasky Medical Center in Tel Aviv, Israel.
He added: “It seems that if you are not treated, we call it’waiting for observation’ or there is no active disease, you can get more benefits from the vaccine. Their best response is that they have recoveredThis makes sense, because his immune system has a chance to recover. “
In addition to not receiving active CLL treatment, younger age, being a female, and having a normal immunoglobulin level at the time of vaccination can independently predict a higher response rate to the vaccine.Except one Poor qualitative antibody response Dr. Herishanu explained that for vaccines, the antibody titers of CLL patients are also lower, which shows that in addition to fewer patients who respond to the vaccine, the response intensity is also lower.
In this study, the researchers recruited 167 CLL patients and 53 healthy controls from December 2020 to February 2021.All participants received two doses COVID-19 messenger RNA vaccine BNT162b2 (Pfizer) was 21 days apart; this was the only vaccine used in Israel at the time of the study. The average age of the patients was 71 years and 67% of men.
58 patients (34.7%) did not receive treatment; Seventy-five (44.9%) people are receiving active treatment; 24 cases (14.4%) have previously received treatment and have been partially or completely remitted; 10 cases (6%) relapsed. The antibody titer was also measured two weeks after the second dose.
An average follow-up of 75 days after receiving the first injection, and No one is infected By COVID-19. Compared with healthy people, the side effects of the vaccine are not significantly different.
The researchers also studied the immune response to the vaccine based on the CLL treatment the patient received.They found similar low response rates in the following patients Received common targeted therapies Includes Bruton’s tyrosine kinase (BTK) inhibitor (ibrutinib or acalabrutinib) or a combination of Venetog and anti-CD20 antibodies (such as rituximab)
Patients who have never received treatment Anti-CD20 antibody Within 12 months after receiving the COVID-19 vaccine, the response was good. Since only five patients received Venetoclax monotherapy, Dr. Herishanu stated that they could not draw any conclusions about its effect on the response.
People with CLL and other blood cancers are still susceptible Serious illnesses and complications For COVID-19 infection, although the response rate is lower than the ideal level, it is strongly recommended to vaccinate against COVID-19.
The author suggests that additional booster doses of vaccine may be needed for prevention. CLL patients who have completed treatment And there has been no response to the COVID-19 vaccine before, although this requires research.