Nearly 85% of stem cell transplant recipients develop high antibody levels after two doses of Pfizer’s Covid vaccine
- French researchers found that 83% of stem cell transplant recipients develop high antibody levels after both injections of Pfizer’s COVID-19 vaccine
- More than half of the study participants developed the appropriate antibody response after just one injection
- Recipients of a stem cell transplant often have a form of blood cancer, which makes them extra vulnerable to the virus
- Previous studies have shown that people with blood cancers develop low COVID-19 antibody levels from the vaccines
Despite past concerns, COVID-19 vaccines are likely effective in people who have received stem cell transplants, a new study finds.
Researchers at the University Hospital of Nantes in France used antibody tests to discover whether or not those who received the transplants generated an appropriate antibody response to the injections.
Previous studies had shown that people with blood-based cancers — who often receive stem cell transplants as a treatment — do not produce high levels of antibody after inoculation.
The team found that 64 percent of stem cell transplant recipients developed antibody responses after receiving one dose, and 83 percent did so after both doses.
French researchers found that 54% of stem cell transplant recipients developed a high antibody response after one shot of the virus (middle bar) and 83% after both shots (right bar)
Researchers, who published their findings Tuesday in JAMA Network Open, gathered 117 participants who had recently undergone allogeneic stem cell transplants and had no history of COVID-19.
Many stem cell transplant recipients receive the treatment because of a blood-related cancer such as leukemia.
The transplants are used to replace blood cells that were damaged while a person was receiving chemotherapy or other treatment that can destroy the cells.
Allogeneic means that the stem cells come from the donor’s bone marrow rather than from the patient’s bone marrow.
Transplants can also help replace blood cells that work as part of a person’s immune system to fight off infections and viruses.
Each patient received the full two-shot regimen of the Pfizer-BioNTech vaccine.
The participants were then tested for antibodies before receiving a vaccination, on the day they received the second injection – testing antibody production after the first injection – and about 35 days after receiving the second injection.
The team found that after the first shot, 54 percent of the participants — 63 out of 117 — had developed appropriate antibody responses.
After two injections, it was found that 83 percent, or 97 out of 117, had developed high antibody responses.
However, only 62 percent of those who received both injections achieved the highest classification of antibody levels, reaching the general population after both injections.
The results are promising and could mean that many of those with stem cell transplants could be just as protected against the virus as they are against the general population.
Patients with blood cancers are significantly more likely to die from Covid, and previous studies have shown that they are less likely to develop antibodies to the vaccine.
Although scientists have yet to develop a tangible link between higher antibody levels and greater protection against the virus, although they do believe there is a link.
Despite the potential to receive little protection, cancer patients are still advised to get the COVID-19 vaccine as soon as possible.
Currently, in the US, more than 63 percent of the total population has received at least one vaccination and 54 percent of people are fully vaccinated.