New York: Patients, who had organ transplants, remain vulnerable to Covid-19 infections even after a second vaccine dose, finds a study that urges people who are immunocompromised to strictly adhere to wearing masks, and maintain physical distancing, even after vaccination.
The study, led by researchers at Johns Hopkins University in the US, showed that after two doses of Moderna or Pfizer-BioNTech vaccine against SARS-CoV-2 -- the virus that causes Covid 19, just 54 per cent people who have received solid organ transplants produced sufficient antibodies. The findings are published in the Journal of the American Medical Association (JAMA).
"Transplant recipients should not assume that two vaccine doses guarantee sufficient immunity against SARS-CoV-2 any more than it did after just one dose," said Dorry Segev, Professor of Surgery and Epidemiology at the Johns Hopkins School of Medicine.
"Based on our findings, we recommend that transplant recipients and other immunocompromised patients continue to practice strict Covid-19 safety precautions, even after vaccination," added lead author Brian Boyarsky, surgeon at the varsity.
People who receive solid organ transplants (such as hearts, lungs and kidneys) often must take drugs to suppress their immune systems and prevent rejection. Such regimens may interfere with a transplant recipient's ability to make antibodies to foreign substances, including the protective ones produced in response to vaccines, the researchers said.
The study evaluated this immunogenic response following vaccination from either Moderna or Pfizer-BioNTech in 658 transplant recipients, none of whom had a prior diagnosis of Covid-19, between December 16, 2020, and March 13, 2021.
The team found that only 98 of the 658 study participants -- 15 per cent -- had detectable antibodies to SARS-CoV-2 at 21 days after the first vaccine dose.
At 29 days following the second dose, the number of participants with detectable antibodies rose to 357 out of 658 -- 54 per cent. After both vaccine doses were administered, 301 out of 658 participants -- 46 per cent -- had no detectable antibody at all while 259 -- 39 per cent -- only produced antibodies after the second shot.