People who have received organ transplants or are immunocompromised may not be able to produce potent antibodies after the COVID-19 vaccination, according to a study led by John Hopkins Medicine researchers.
The authors of the study studied people who are immunocompromised and their response to their first dose of one of the two mRNA vaccines — Moderna and Pfizer-BioNTech.
Their findings, as published in the Journal of the American Medical Association, demonstrated that only 17 per cent produced detectable antibodies against the SARS-CoV-2 virus.
“This is in stark contrast to people with healthy immune systems who are vaccinated, nearly all of whom mount a sufficient antibody defense against COVID-19,” says study lead author Brian Boyarsky, M.D., a surgery resident at the Johns Hopkins University School of Medicine.
For the study, the researchers evaluated the vaccine immunogenic response for 436 transplant recipients, none of whom had a prior diagnosis of COVID-19 or tested positively for SARS-CoV-2 antibodies.
Fifty-two percent were administered a single dose of the Pfizer-BioNTech vaccine and 48 per cent received one shot of the Moderna vaccine. The median time since transplant for the participants was 6.2 years.
At a median time of 20 days after the first dose of the vaccine, the researchers report that only 76 of the 436 participants (17 per cent) had detectable antibodies to the SARS-CoV-2 virus.