Despite being severely low on immunity levels, blood cancer patients generate strong responses against SARS-CoV-2 after vaccination, on par with that of healthy individuals, according to a research.
Researchers from the University of Melbourne undertook the most comprehensive analysis of adaptive SARS-CoV-2 immunity to date in haematology patients of varying diseases and treatments across three doses of Covid-19 vaccination in comparison to healthy individuals.
The findings published in the journal Cell Reports Medicine shows that blood cancer patients highly benefit from receiving three doses of vaccination. The vaccines boost their levels of T cells, the white blood cells that kill viral infected cells, irrespective of the patient's B-cell numbers and antibody response.
"It is important to really understand vaccine efficacy in this immuno-suppressed high-risk group of patients to help prevent severe SARS-CoV-2 infection," said Dr Oanh Nguyen, Senior Research Fellow at the varsity's Peter Doherty Institute for Infection and Immunity (Doherty Institute).
"This group is at high risk of viral infectious diseases, such as influenza and SARS-CoV-2, and yet they are not always included in pre-clinical trials that test vaccine efficacy," Nguyen said.
The team also looked at the characteristics of these T cells that are generated after vaccination, and "found that these signatures are very similar to healthy individuals that are either infected or vaccinated.
These findings are really important and super exciting for cancer patients", Nguyen said. According to Katherine Kedzierska, a Laboratory Head at Doherty Institute the study provides key insights for future immunisation strategies with vaccines such as influenza which predominantly induce B cell immune responses.
"What we have shown is that people with comorbidities that have a heavily impacted B cell immune arm, can have an mRNA vaccine to elicit T cells and give them that extra level of protection," Kedzierska said.
The study results are also important for clinicians working with blood cancer patients. "Clinicians can be confident that it is safe and beneficial for their patients, who are heavily immunocompromised and vulnerable to severe Covid-19 infection, to receive vaccination against SARS-CoV-2.
Regardless of their diseases and treatments, Covid-19 vaccination generates strong T cell immunity in this group," said the researchers.