A small study offers the first clue that an extra dose of COVID-19 vaccines may well give some organ transplant recipients a needed boost in protection.
Even though most people who get vaccinated celebrate a return to near-normality, millions of people who take immunosuppressive drugs due to transplants, cancer or other disorders remain in limbo – not knowing how bad they are. truly protected. It is simply more difficult for vaccines to stimulate a weakened immune system.
Monday’s study only followed 30 transplant patients, but it’s an important step in whether the booster doses might help.
It didn’t help everyone. But of the 24 patients who appeared to have no protection after the two routine vaccinations, eight of them – a third – developed anti-virus antibodies after an additional injection, researchers at Johns Hopkins University reported. in Annals of Internal Medicine. And six others who had had minimal antibodies all received a big boost from the third dose.
“It’s very encouraging,” said Dr Dorry Segev, a transplant surgeon from Hopkins who helped lead the research. “Just because you’re completely negative after two doses doesn’t mean there’s no hope.”
Next step: Together with the National Institutes of Health, the Segev team hopes to start a more rigorous testing of a third vaccination in 200 transplant recipients this summer.
For transplant patients, powerful immunosuppressive drugs prevent rejection of their new organs but also leave them extremely vulnerable to the coronavirus. They have been excluded from initial testing for COVID-19 vaccines, but doctors are urging they get vaccinated in the hope of at least some protection.
Some take advantage of it. Hopkins’ team recently tested more than 650 transplant recipients and found that about 54% of them contained anti-virus antibodies after two doses of the Pfizer or Moderna vaccines – although generally less than in those vaccinated. otherwise healthy.
This is not just a concern after organ transplants. A study of patients with rheumatoid arthritis, lupus and other autoimmune disorders found that 85% of the antibodies had developed antibodies, said Dr. Alfred Kim of Washington University in St. Louis. But those who used particular types of immunosuppressive drugs produced considerably lower levels which are cause for concern.
“We tell our patients to act like the vaccine won’t work as well as their family and friends,” said Kim, who would also like to test a third dose in autoimmune patients. “This is very frustrating news for them.”
Doctors sometimes give extra doses of other vaccines, such as hepatitis B vaccine, to people with weakened immune systems.
And guidelines published in France recommend a third injection of COVID-19 for certain severely immunocompromised people, including transplant recipients, Segev noted.
The United States has not authorized additional vaccinations against COVID-19. But across the country, a growing number of immunocompromised patients are seeking a third dose on their own – the people Hopkins sought to test.
In San Francisco, Gillian Ladd agreed to have blood tests before and after an extra dose. Kidney and pancreas transplant recipient Ladd, 48, was terrified of leaving home after learning she had no measurable antibodies despite two injections of Pfizer.
With the extra dose, “I got what I needed to survive,” Ladd said, but she still sticks to masks and other precautions.
“I am as careful as possible while acknowledging that I am returning to the world of the living,” she said.
More research is needed to find out if a third dose really helps, who is the better candidate, and if there are any brand differences – and if the additional immune stimulation might increase the risk of organ rejection.
But Segev warns that boosters aren’t the only possibility. In addition to antibodies, vaccinations normally stimulate other protections such as T cells that can ward off serious illness. He and several other research groups are testing whether immunocompromised patients benefit from this benefit.
For now, “the best way to protect these people is for others to get vaccinated” so that they are less likely to be exposed to the coronavirus, said Kim of the University of Washington.
The Associated Press’s Department of Health and Science receives support from the Department of Science Education at Howard Hughes Medical Institute. The AP is solely responsible for all content.
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