COVID vaccines have only 17% detectable antibodies against the SARS-CoV-2 virus

When clinical trials were conducted to determine the immunogenicity (the ability to elicit an immune response) of the first two vaccines directed against SARS-CoV-2, the virus that causes COVID-19, one group was not included: people who have received solid organ transplants and others (such as those with autoimmune disorders) who are immunosuppressed.

Now, Johns Hopkins Medicine researchers have tried to rectify that inequity, taking one of the first looks at how immunosuppressed people respond to their first dose of one of the two mRNA vaccines, Moderna and Pfizer-BioNTech, currently being administered. all over the world. . As published on March 15, 2021, its findings in an investigative letter in the Journal of the American Medical Association disappointingly show that only 17% produced detectable antibodies against the SARS-CoV-2 virus.

This is in stark contrast to people with healthy immune systems who are vaccinated, almost all of whom mount a sufficient antibody defense against COVID-19. “

Brian Boyarsky, MD, study lead author and surgery resident, Johns Hopkins University School of Medicine

The study evaluated the immunogenic response of the vaccine for 436 transplant recipients, none of whom had a prior diagnosis of COVID-19 or tested positive for antibodies to SARS-CoV-2. The median age was 55.9 years and 61% were women. 52% received a single dose of the Pfizer-BioNTech vaccine and 48% received a single injection of the Moderna vaccine. The median time since transplantation for the participants was 6.2 years.

At a median of 20 days after the first dose of the vaccine, the researchers report that only 76 of the 436 participants (17%) had detectable antibodies against the SARS-CoV-2 virus. The researchers also found that among the 76 transplant recipients, those most likely to develop an antibody response were those younger than 60 years who did not take antimetabolites for immunosuppression and who received the Moderna vaccine.

“Given these observations, we believe that the US Centers for Disease Control and Prevention should update their new guidelines for vaccinated individuals to warn immunosuppressed individuals that they may still be susceptible to COVID-19 after vaccination, “says study lead author Dorry Segev, MD, Ph.D., Marjory K. and Thomas Pozefsky, professor of Surgery and Epidemiology and director of the Organ Transplant Epidemiology Research Group at the School of Medicine. from Johns Hopkins University. “As the guidelines are currently written, people assume that vaccination means immunity.”

Segev says that future studies will define the immunogenic response of organ transplant recipients and other immunosuppressed patients after a second dose of vaccine. Further studies will look at the impact of a broader profile of the immune system, including the characterization of immune cells that are reminiscent of SARS-CoV-2 after vaccination and produce antibodies or directly attack the virus in response to the presence of the virus, to help guide vaccination strategies for this population.