Covid vax ‘less effective’ in people with blood cancer: study

Jerusalem, April 18 (IANS) The two-dose Covid-19 mRNA vaccine may be even less effective in people on treatment for certain types of blood cancers, researchers have said in two new studies.

The studies, published in the journal Blood, suggest that the Covid-19 mRNA vaccine may have reduced efficacy in people with chronic lymphocytic leukemia (CLL) and multiple myeloma, – two types of blood cancer – compared to healthy people.

However, vaccination against Covid-19 is strongly recommended in both groups, the researchers said.

“Even if response rates were not optimal, patients with CLL should still receive the vaccine and, if so, it may be best to do so before starting treatment for CLL, although the disease is -even could affect the response, ”said lead author Yair Herishanu, associate. Professor of hematology and head of the CLL service at Tel Aviv Sourasky Medical Center in Israel.

In the first study of 167 patients with CLL and 53 healthy adults, all participants received two doses of Covid messenger RNA vaccine BNT162b2 (Pfizer).

The immune response in patients with CLL was found to be dependent on their cancer treatment process: those on active cancer treatment had significantly lower response rates (16%) to the vaccine.

Treatment-naïve patients (those whose disease is monitored but not yet treated) had a response rate of 55.5%. The response to the vaccine was significantly higher in people who completed treatment for CLL at least one year before vaccinationA (94%).

“Overall, the response rate to the vaccine was significantly lower than what we see in the general population, which is likely attributed to the presence of the cancer itself and some treatments for CLL,” Herishanu said. .

In addition, patients with CLL also had lower antibody titers, meaning that the intensity of the response was also lower, Herishanu explained.

Similar results have been reported in patients with multiple myeloma. After the first dose of the same vaccine in elderly patients with multiple myeloma, only 20.6% showed neutralizing antibodies.


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