These clinical observations are not surprising. Immunocompromised people have been excluded from studies of COVID-19 mRNA vaccines.
Due to the administration of immunomodulatory drugs after transplantation, frequent procedures, and multiple interactions with healthcare, transplant patients are more vulnerable to COVID-19. When combined with ineffective vaccination, these patients are even more likely to develop dangerous infections and complications.
New research from Johns Hopkins University Hospital shows that there may be a way to improve COVID-19 immunity in these patients: give them a third dose of the COVID-19 vaccine.
The study, published in the Annals of Internal Medicine, followed 30 solid organ transplant patients at Johns Hopkins who had received two doses of a COVID-19 mRNA vaccine, from Pfizer or Moderna. Immunity to COVID-19 was estimated via antibody tests and was classified from no immunity to high immunity based on the level of COVID-19 antibodies found in the blood of patients.
After two doses, 80% of these immunocompromised patients had no immunity. 20% of these patients had “weak immunity”. With the addition of a third COVID-19 vaccine, either Johnson & Johnson, Pfizer or Moderna, immunity increased in 33% of those who previously had no immunity and in 100% of those who previously had ” low immunity ”.
” It’s a [study of] about 30 patients. This is not a formal 200 patient trial with a standardized timeline and endpoints, but this is sufficient preliminary data to be very encouraging, ”Dr. Dorry Segev, vice-president, told ABC. -Associate Chairman of the Department of Surgery at Johns Hopkins University Hospital and study author. New.
“It gives me hope that transplant patients have an immune system that will eventually be able to mount an effective response to the vaccine, but might just need help doing so. Like, say, a third dose, ”Segev said.
While the vaccine response was promising, experts note that immunity varied from patient to patient. This variability probably depends on the medications associated with the transplant patients and the time elapsed since their transplant.
“Those on antimetabolites,” a class of drugs associated with transplantation, “are less likely to have a good antibody response,” Segev said. “Those who are closer to their transplant, and probably at a higher overall level of immunosuppression, will likely have a higher [response]. The further away you are from the transplant, the better your chances of having an immune response.
Although COVID-19 antibody testing was used in this study, the U.S. Centers for Disease Control and Prevention continues to not recommend its use to the general public. As stated on the CDC website, “Antibody tests are not currently recommended to assess COVID-19 immunity after COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.” .
“Going to have the antibodies tested yourself, right now, is going to lead to more chaos than information,” Segev said.
Patients with strong immune systems are more likely to have a robust immune response to vaccines. Therefore, an antibody test that shows “no response” is likely to be a false negative.
There is an immunity developed at the cellular level after infection and vaccination which is more difficult to measure. These T and B cell responses may offer protection regardless of what an “antibody test” dictates.
The CDC also warns that every antibody test is different. Some offer binary tests, a simple yes or no result, while others indicate a spectrum of immunity. The clinical significance of antibody tests is still uncertain for the general population. However, in specific patient populations and clinical studies this can be extremely useful.
“In the context of a discussion with a doctor or a trial, testing is very important. It works as a reasonable substitute for what’s going on below the surface, ”Segev said.
With nearly 39,000 solid organ transplants in 2020 and 17,286 this year alone, according to the United Network for Organ Sharing, a significant number of patients could benefit from an additional vaccine against COVID-19. Due to poor immunity, these patients already need additional doses of hepatitis B and influenza vaccine in order to establish immunity. A third dose in a series of COVID-19 vaccines would therefore not be unreasonable.
Further clinical testing is needed to better understand the use of three COVID-19 vaccines in immunocompromised patients.
“These results are too low to recommend three doses of the vaccine for such patients,” Dr. Vincent Racaniello, Professor Higgins and physician in the Department of Microbiology and Immunology at Columbia University, told ABC News, who did not was not involved in the study. “The results show that a larger clinical trial should be performed to assess the value of a third dose in this population. “
“My recommendation for any transplant patient today would be to get vaccinated but to act without being vaccinated,” Segev said. “I would not recommend that transplant patients assume at this time that they have protective immunity,” he said.
“Currently, these patients should be carefully monitored for infection and, if they are positive, should be treated with monoclonal antibodies as soon as possible,” Racaniello said.
Natalie S. Rosen, MD, is a resident physician in internal medicine at Johns Hopkins Hospital and a contributor to the ABC News Medical Unit.