- It can be hard for people with transplant organs to derive the same benefits from vaccines as other people.
- A new study suggests giving them 3 doses of COVID-19 vaccines, instead of 2, can help.
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For tens of thousands of Americans with suppressed or compromised immune systems, getting fully vaccinated against COVID-19 hasn’t led to disease protection. Receiving a third vaccine dose might help fix the problem, at least for some of those patients.
A new study – conducted on patients with organ transplants who took it upon themselves to get illicit vaccine booster shots in the US – suggests that the third try may be the charm when it comes to some immunocompromised people and vaccination.
Out of the 30 patients enrolled in the study, published Monday in the Annals of Internal Medicine, 12 achieved high antibody levels after the third vaccine, two patients had low but detectable antibodies, and the remaining 16 patients remained antibody negative after their third dose booster.
It didn’t really seem to matter whether the participants mixed and matched their shots. There was limited success with all different combinations of third doses of Pfizer, Moderna, and Johnson & Johnson (none of the patients had J&J initially).
“People want to return to their lives, and they will go to great lengths to do so: to go back to work, to go back to church, to see the grandkids,” Dr. William Werbel, an infectious disease clinician at Johns Hopkins who led the new study, said. “They were somewhere on the spectrum between frustrated and desperate.”
Hoping that a third dose might be the ticket to resuming some of their bygone activities, many rolled up their sleeves once again. Their mixed success in the third dose trial is a promising signal that COVID-19 booster shots can be safe and effective, and that the side effect profile of a third shot could be quite similar to a second.
Hundreds of transplant patients have already gotten a third vaccine dose
Werbel said there were already “hundreds” of transplant recipients around the US who’d made up their minds to get a third vaccine, even though the practice is not federally recommended.
Rather, because many transplant patients are active on a nationwide organ network that connects patients and doctors to share experiences and best practices, he already knew it was happening.
“We basically had the privilege of working with patients who said, ‘Hey, I’m going to get vaccinated next week. How can I help contribute to studying whether this works?'” Werbel said. “I have to plead somewhat ignorance about how people were doing it, because it’s not authorized that way.”
He called the new study findings, which are still preliminary, “encouraging.” But the third doses were not a smashing success, only markedly improving antibody levels in about half of the participants.
That doesn’t necessarily mean that the 16 patients in the study who remained antibody negative gained no benefit from taking the third vaccine dose; antibodies aren’t the only piece of the puzzle in determining a person’s immunity to COVID-19. But it does suggest there might be something about the way their immune systems operate that isn’t giving them great vaccine protection.
“These patients take medicine specifically designed to prevent rejection of their heart, or their lung, or their kidney, whatever was given to them,” Werbel said. “These medicines are explicitly designed to reduce the potential to react to new things. That’s why patients don’t always create good response to vaccine antigens, the proteins in the vaccines.”
In France, the government does endorse third doses of COVID-19 vaccines for organ transplant recipients and others with compromised immune systems.
Proof of concept that boosters can work
The study is one of the first to show that mixing and matching booster doses of COVID-19 vaccines is both safe and effective – at least for some people.
“It’s a little hard to generalize to the healthy population, just because the healthy population cranks out so much antibody and other immune response to these vaccines,” Werbel said.
Side effects after a third vaccine dose were similar to those experienced after a second, including mild to moderate fatigue and arm pain. One patient rejected her donated organ – a heart – seven days after her booster vaccination, but it’s unclear whether that was related to the vaccine administration. (She is now recovering.)
Werbel cautioned that it is still too soon to say how well-protected from disease these patients may be through vaccination.
“Transplant patients really shouldn’t consider themselves to be fully protected or vaccinated until we learn more, and that honestly means it’s important for people around them – really important for people around them – to get vaccinated,” he said.