Transplant recipients remain vulnerable to COVID-19 after vaccination


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Dr. Brian Boyarsky

Solid organ transplant recipients receiving two doses of the SARS-CoV-2 mRNA vaccine show detectable antibody responses that are higher than the levels seen after a dose, but the levels are still significantly lower than those seen in humans. who are not immunocompromised. research indicates.

“It is very worrying that only a little over half of the population has developed antibodies against the vaccine, as we know that in healthy people it is almost 100%,” said the author, Brian Boyarsky, MD, PhD, a research followed in the Johns Department of Surgery. This was stated by Hopkins University School of Medicine in Baltimore, Maryland Medscape Medical News.

“The message being taken home is that transplant recipients and other immunocompromised people should not take on immunity after vaccination.”

The study was published online May 5th JAMA.

Immunocompromised patients excluded from COVID-19 vaccine trials

Evaluation of the effects of the SARS-CoV-2 vaccine on solid organ transplant recipients is especially important since they and other immunocompromised individuals were generally excluded from trials against the COVID-19 vaccine.

“In general, transplant recipients have a slightly blunt response to vaccination, but this was a new mRNA platform, so we didn’t know how these vaccines would work in these patients,” Boyarsky explained.

In a previous studies, Boyarsky and his team found that most solid organ transplant recipients were unable to show appreciable antibody responses to the first dose of the vaccine.

To investigate responses after the second dose, the researchers evaluated data on 658 transplant recipients from across the United States who received two doses of the Pfizer or Modern SARS-CoV-2 mRNA vaccine between December 2020 and March 2021. .

Participants included 396 from the previous first-dose study.

At an average of 21 days after the first dose, antibodies were detected in 15% of participants.

After an average of 29 days after the second dose, only 54% of participants had detectable antibodies.

In another dissection of the results after two doses among the 658 patients, only 15% had measurable antibody responses after dose 1, as well as dose 2, 46% had no antibody response even after dose 1 nor of dose 2 and 39% who had no antibody response after dose 1 showed a response after dose 2.

Type of impact of immunosuppression Vaccine response

Among 473 of the patients receiving immunosuppressive treatment with antimetabolites, only 8% had antibody response after dose 1 and dose 2; 57% had no antibody response after dose 1 or 2 and 35% had no antibody response after dose 1, but did show a response after dose 2.

Of the 185 patients who were not treated with antimetabolites, the results were better, with 32% response after both doses, 18% no response after dose 1 or 2, and 50% no response after dose. dose 1, but antibodies after dose 2.

Despite the fact that immunocompromised people tend to have lower responses to vaccines in general, the degree of reduced effect among patients in general was unexpected, Boyarsky said. Medscape Medical News.

“What surprised us was the magnitude of the decreased immunogenicity in these patients,” he said.

“For us, this means that there is clearly some interaction between the transplant immunosuppression and perhaps the underlying diseases or comorbidities that patients have that make these vaccines less immunogenic in our populations. “

With kidney transplantation accounting for the majority of transplant recipients in the United States, these patients were slightly overrepresented in the study, Boyarsky noted.

“However, the results were more related to the immunosuppressive regimen than the type of organ transplanted,” he stressed.

Potential options for improving antibody responses could be the addition of a booster shot or the potential modification of immunosuppressive regimens in some cases.

“This is something that should be done very carefully because these immunosuppressive drugs are obviously very important for transplant recipients to prevent their bodies from rejecting organs,” Boyarsky explained.

He stressed, however, that the results do not necessarily suggest that transplant patients do not get any protection against vaccines and, given their increased risk of serious effects of COVID-19, patients should be vaccinated.

“The fact that we do not detect robust antibody responses to vaccination does not mean that there are no other cells involved in the immune system, for example, T cells or memory B cells, which may contribute to a certain level of immunity or protection from serious illness. We also recommend that family members and transplant recipient social networks also be vaccinated to help protect the most vulnerable members of society. “

Boyarsky has done it has not reported any relevant financial relationships.

JAMA. Published online May 5, 2021. Full text

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