The U.S. government is considering ways to protect roughly 10 million immunocompromised Americans, who may have gotten inadequate coverage from their COVID-19 vaccines.
The Food and Drug Administration, along with the Centers for Disease Control and the National Institutes of Health, are evaluating the potential use of booster doses, an FDA spokesperson told USA TODAY.
“The agencies are engaged in a science-based, rigorous process to consider whether or when a booster might be necessary. This process takes into account laboratory data, clinical trial data, and cohort data,” the spokesperson said Friday via email.
Immunocompromised people, who make up about 3% of the U.S. population, are in a different category than other Americans, because they may not have mounted an adequate immune response to their COVID-19 vaccinations, Dr. Anthony Fauci told USA TODAY’s editorial board on Friday.
“Some mechanism needs to be done quickly to get those people protected,” said Fauci, a presidential advisor and director of the National Institute of Allergy and Infectious Diseases.
Some people are already taking the matter into their own hands, deciding to get extra doses – either a second or a third shot depending on which vaccine they got the first time. One doctor referred to the phenomenon on Twitter as “booster mania.”
CDC director Dr. Rochelle Walensky said in a briefing last week she hoped such people could be captured in research studies, to better understand the response to a booster dose and whether they are safe.
Those who are immunocompromised, including transplant recipients and some cancer patients, are not only at higher risk for severe COVID-19 but may act as Petri dishes in which new and more dangerous variants can develop. This makes immunizing them and protecting them from infections even more vital, a piece published Wednesday in the New England Journal of Medicine confirmed.
Two weeks ago, several members of a federal advisory committee said people who are severely immunocompromised should consider getting a third dose of a COVID-19 vaccine. They also should take other precautions like wearing masks and making sure those around them are vaccinated. The Advisory Committee on Immunization Practices presented data at its July 23 meeting suggesting a booster shot was unlikely to cause harm and might be helpful.
However, the committee doesn’t have the regulatory authority to officially recommend a third shot. For that, the FDA must act. The Washington Post reported Friday that the FDA is fast-tracking a plan to provide shots to the immunocompromised.
Boosters not now needed for most
Fauci also made a clear distinction between those who are immunocompromised – and were never fully protected – and otherwise healthy, vaccinated people who are worried their immunity is waning.
People with healthy immune systems most likely are still adequately protected, Fauci said, and should wait longer for a booster dose.
“According to our data, it doesn’t look like we need to vaccinate with an additional shot right now the way we do with the immunocompromised, but it’s very clear that the durability is attenuating as you go on,” he said. “So we all feel that sooner or later (boosters will be needed), likely with the elderly before the young.”
Dr. Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, has asked countries to hold off on booster doses for otherwise healthy people until after the more vulnerable receive their initial shots.
Since vaccines are believed to prevent the vast majority of hospitalizations and deaths for an extended period, he said it will do more good to protect those who have never been vaccinated than to boost those who have.
Ellie Murray, an epidemiologist at the Boston University School of Public Health, said her data supports his argument.
Boosting people who’ve already had shots will make a tiny difference in slowing the global pandemic, while giving those same number of doses to people who are unvaccinated will have much more impact, she said in an interview. Even fully vaccinating the 8% of people who’ve only had one dose of a two-dose regimen would be more effective, her simplified calculations show.
“There’s a lot of unknowns about whether that extra dose would even really help” someone who gets a booster after their initial vaccination, Murray said. The vaccines are so effective, she said, that it may be more protective for an 86-year-old man, for instance, to “get the cashier at his favorite restaurant vaccinated,” than to get a third dose himself.
Gauging immune response is tricky
So far, there is very little data or guidance on how to treat immunocompromised people, said Dr. Lawrence Corey, who leads the COVID Prevention Network at the Fred Hutchinson Cancer Research Center in Seattle.
“Some people can shed virus for hundreds of days,” he said.
Studies of transplant recipients and other immunocompromised people show that “about 50% of those who get a third dose respond and that the third dose is well-tolerated,” he said.
But it’s hard to even know whether someone has mounted an immune response. CDC doesn’t recommend antibody testing outside of a clinical trial because it’s not clear what level of antibody is sufficient to indicate protection.
Dr. Len Horovitz an internist and pulmonologist at Lenox Hill Hospital in New York City, said levels range from under 1 to 2,500. “What constitutes real protection and how long it lasts” – no one knows, he said.
“I do think we’re headed for boosters” for everyone, Horovitz said. But he doesn’t dispense them even to his immunocompromised patients because he doesn’t have access to vaccine and he wants to wait for federal officials to declare that such boosters are safe.
Both Moderna and Pfizer-BioNTech have released studies showing their vaccines are protective for at least six months.
The delta variant, which Fauci said now constitutes 93% of infections in the United States, is far more contagious and appears to be causing more “breakthrough” infections in people who are vaccinated. These vaccinated but infected people may also be contagious, which was not seen with previous variants.
Still, the vast majority of those hospitalized with COVID-19 are unvaccinated, Fauci said, suggesting that the vaccines, including one from Johnson & Johnson, are doing what they were designed to do: protect against serious illness.
Fauci said it isn’t clear yet how many doses may eventually be needed. Different pathogens require a different number of shots to provide long-term protection, with people getting three hepatitis shots, for instance, and four or five against the measles.
“We just picked out two because we needed to move our butts to get a vaccine out there,” he said. “The idea that you only need two shots per vaccine was just a decision made out of the urgency of the situation.”
Right now, boosters would be repeats of the shots already given.
In the future, experts said, vaccines may be targeted to specific variants, but for the moment, studies show that a repeat shot extends protection, even against the delta variant.
For instance, a recent study from Novavax, which doesn’t yet have an authorized vaccine, shows that a third dose given six months after vaccination generates four-fold more antibodies against delta than the original shots, company president and CEO Stanley Erck said Friday.
Novavax, a small company that has struggled to scale up production of its vaccine, hopes to provide booster shots to Americans early next year and primary shots around the world as early as the end of this year, Erck said.
To prove the safety and effectiveness of an extra shot, companies are running clinical trials. Paul Evans, CEO of Velocity Clinical Research, a trial company based in Raleigh, North Carolina, is testing booster doses among people who were in Pfizer-BioNTech’s original COVID-19 vaccine study.
That trial, beginning shortly, will include about 1,000 mostly healthy people. Evans described this type of trial as “more nuanced” than the larger study that proved the vaccine’s effectiveness. “It’s a little bit different here, because this is to what extent do we need to enhance protection that subjects (already) have,” he said.
Immunocompromised at high risk
Fauci said that because he is over 80, he is likely to need a booster sooner than younger people.
The immune system weakens with age and the antibody response to COVID-19 vaccination is believed to fall off substantially around 80, though it may be younger among minority populations, said Dr. Maria Torroella Carney, an internist and geriatrician at New York-based Northwell Health.
She said she’s worried about her older and immunocompromised patients, but will wait for government guidance and more data before recommending boosters. “There’s still a lot of unknowns and what to make of it,” she said. “I don’t know if we’re going to be contributing to harm both individually or to society.”
Millions of people are immunocompromised due to powerful drugs they receive as part of cancer treatment, after getting an organ transplant, being on dialysis or because they have HIV, as well as from drugs used to treat autoimmune disorders such as multiple sclerosis, psoriasis, rheumatoid arthritis and inflammatory bowel disease.
They are at higher risk of becoming severely ill or dying if they get COVID-19.
Because their immune systems are suppressed, in some cases their bodies aren’t able to respond to vaccines against COVID-19, leaving them exposed to infection even if they’ve been vaccinated.
Dr. Camille Nelson Kotton, clinical director of transplants at Massachusetts General Hospital, has had patients come close to death and some die from COVID-19 infections.
“This is a really high-risk situation for our patients,” she said.
Protecting the millions of people who are immunocompromised requires everyone around them to get vaccinated, providing a ring of protection by their loved ones, their families, the people they live with and the people in their communities, she said.
“This is why it’s so incredibly important to get vaccinated, to protect others who are vulnerable,” Kotton said.
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