A second dose of the vaccine every three weeks, however, significantly increased their protection, with researchers calling for earlier increases in this group in the UK. The UK vaccination strategy currently involves a 12-week gap between doses of coronavirus vaccines; Pfizer recommends 21 days between doses.
The study looked at the impact of the Pfizer-BioNTech vaccine on 205 participants – 54 healthy volunteers and 151 elderly patients with solid cancer, such as breast or prostate cancer and hematological (blood) cancers, such as leukemia. The prepress study has not yet been evaluated by colleagues or published.
The researchers looked for levels of antibodies and T cells in their blood to identify the level of immune response generated against the coronavirus.
Three weeks after a vaccine dose, an antibody response was found in 39% of solid cancer patients and only 13% of blood cancer patients. The response to healthy volunteers was 97%.
In solid cancer patients who received a second dose three weeks after the first, the antibody response increased by up to 95% within two weeks of growth. There were not enough booster vaccines given to blood cancer patients to determine the response in that group.
Further evidence of the need for an increase was demonstrated by the fact that the level of antibodies increased to only 43% in people with solid cancer and to 8% in those with blood cancer five weeks after their first dose. It was 100% healthy volunteers.
“Our data provide the first real evidence of immune efficacy following a dose of Pfizer vaccine in populations of immunocompromised patients. “We show that after the first dose, most patients with solid and haematological cancer remained immunologically unprotected until at least five weeks after the primary injection. But this poor single-dose efficacy can be saved with an early booster on day 21,” he said. Dr. Sheeba Irshad, a senior clinical lecturer at the School of Cancer and Pharmaceutical Sciences who led the research.
“Based on our findings, we would recommend an urgent review of the vaccination strategy for clinically extremely vulnerable groups. Until then, it is important that cancer patients continue to comply with all existing public health measures, such as social distancing and protection when attending hospitals, even after vaccination, “Irshad added in a statement.
Stephen Evans, a professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, stressed that certain limitations need to be considered.
“Changing UK policy on delaying a second dose of vaccine has allowed authors to make some comparisons between those who received the second dose within 21 days and those who did not. They have not yet provided data on those who received the second dose. after a 12-week delay, “he said in a statement at the Science Media Center in the UK.
“However, these results suggest that vaccines cannot protect both cancer and non-cancer patients,” he added.
“All of these findings are consistent with our understanding of the function of the immune system in cancer patients,” said Shoba Amarnath, a researcher at the University of Newcastle at the University of Newcastle’s Cancer Center. “We know that the immune system in cancer patients is compromised compared to healthy controls. Therefore, a second vaccine stimulus prepares the irregular immune system to function at the same efficiency as healthy controls.
The study data support the idea that in patients with solid cancer a considerable delay in the second dose will prolong the period in which cancer patients are at risk of SARS-CoV-2 infection.