FDA advisers vote in favor of new RSV vaccine to protect newborns

CNN
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Independent vaccine advisers for the U.S. Food and Drug Administration on Thursday voted in favor of a recommendation to approve a new vaccine to protect infants from the respiratory syncytial virus known as RSV.

“This is good news for children and mothers across the United States,” said Dr. David Kim, a member of the advisory panel that voted in favor of the vaccine. Kim is director of the Vaccines Division for the US Department of Health and Human Services’ Office of Infectious Diseases. “The burden of respiratory syncytial virus infection is high and preventive care is definitely needed.”

The committee reviewed the vaccine’s safety and efficacy. Advisors unanimously voted that it was effective, but not all agreed on its safety, based on the data collected.

Dr. Holly Janes, professor of Vaccines and Infectious Diseases and Public Health Sciences at Fred Hutchinson Cancer Center, who voted, said, “I think the data on efficacy are very compelling, especially for severe RSV disease. It is highly effective,” he said. Yes to the efficacy question, but no to the safety question.

“I’m still wrestling with the amount of evidence,” she said. “I wish we could discuss a little more and get more data on how these benefits combine with potential risks.”

Approval decisions are now up to the FDA. If a government agency finally approves a vaccine, it will be the first to protect babies from RSV—a goal scientists have been working on for decades.

The maternal vaccine is a single dose given to pregnant women in the third trimester of pregnancy. It causes the development of antibodies that are passed on to the unborn child and provide protection for the first six months of the baby’s life.

Pfizer’s vaccine has been shown in clinical trials to reduce the risk of infants needing medical attention or hospitalization for moderate to severe infections, according to a new analysis by government regulators.

why do we need vaccines

Last year, at children’s hospitals nationwide was very busy respiratory infections Some had to set up tents and makeshift beds in parking lots to accommodate the influx of patients. In addition to the flu and his RSV, COVID-19 has also hit hospitals hard, but even in a typical her RSV season, hospitals are still busy.

RSV is ubiquitous and almost all children become infected with the virus before the age of 2, but most have mild disease. RSV infection often looks like a cold. However, for some children the virus can be very serious.

RSV is the leading cause of hospitalization for children in the United States. Approximately 34 million RSV-associated lower respiratory tract infections occur annually in children under 5 years of age, with approximately 10% requiring hospital admission for treatment. According to research.

In a presentation to the committee on Thursday, the FDA said nearly 80% of children under the age of two who were hospitalized with respiratory syncytial virus had no underlying medical conditions.

Once in the hospital, most children improve with supportive care, but there is no specific drug to treat RSV. In some cases, the infection can develop into pneumonia and even death.

The introduction of palivizumab, a monoclonal antibody developed in the 1990s, greatly improved survival of respiratory syncytial virus infection in infants who are susceptible to serious disease, but only a minority of infants are targeted.

It also comes with some challenges. It has to be given once a month and can be difficult for parents to arrange. Monoclonal antibodies can be expensive and are not available in all countries. The FDA is considering a new monoclonal antibody for infants this year.

Worldwide, approximately 64 million people become infected with RSV each year, and at least 160,000 die. According to the National Institute of Allergy and Infectious Diseases. RSV kills about 1 in 28 infants aged 28 days to 6 months worldwide. Research shows. However, most deaths from respiratory syncytial virus do not occur in hospitals, so the numbers are probably underestimated. 2022 survey found.

RSV is also expensive. every year, US spending Studies have shown that hospital costs for infants with respiratory syncytial virus infection alone are more than $709.6 million.

Vaccine protection does not last forever

The Pfizer vaccine is 82% effective in protecting newborns from severe lower respiratory tract infections in the first three months of life, according to the report. FDA analysis Published on Tuesday. It was 57% effective in saving the infant from seeing a doctor for her RSV infection. By about six months of age, the vaccine was 69% effective in preventing serious illness and 51% effective in avoiding hospital visits for respiratory problems.

Dr. Jay Portnoy, professor of pediatrics at Children’s Mercy Hospital, said: “If vaccines actually live up to the data we’ve seen today, we can guarantee that many babies and their parents will be breathing easier in the years to come. I can,” he said. at the meeting on Thursday.

Portnoy, who voted for a vaccine, said he was grateful that the number of RSV infections could decline in the near future. “Throughout my career, I have seen the epidemic of this disease.”

Pfizer told an FDA panel on Thursday that if the vaccine were widely applied, maternal vaccination could prevent up to 16,000 hospitalizations and more than 300,000 RSV visits each year.

However, the vaccine does not provide lifelong protection for children like the measles vaccine. After about six months, it was almost as effective as a placebo in eliminating the need for the baby to see a doctor.

safety conversation

In the trial, the number of people experiencing reactions and serious adverse events after vaccination was balanced between vaccinated and non-vaccinated groups.

The most common side effects were mild and included fatigue, headache, myalgia, and injection site pain.

At Thursday’s advisory meeting, committee members cast two votes. While 14 to 0 voted that the data supported the efficacy of the vaccine, only 10 to 4 voted that the data supported its safety.

Some members voted “no” on safety issues because Babies whose mothers were infected with RSV had slightly higher rates of preterm birth compared with those who received placebo: 5.7% vs. 4.7%, respectively. This difference is not considered statistically significant and may be due to chance.

Preterm birth rates in both groups were lower than the approximately 10% reported in the general population. Most babies, even preterm babies, were born after the 34th week of gestation, just a few weeks after their due date.

A late-stage trial of another maternal vaccine against respiratory syncytial virus, developed by pharmaceutical company GSK, was halted in February over safety concerns. Mothers who received the GSK RSV vaccine in the study had an increased risk of premature birth compared to mothers who received a placebo, according to a report published in . Journal BMJ.

The GSK vaccine wasn’t being considered on Thursday, but it was something Dr. Paul Offitt had in mind when he voted “yes” for efficacy and “no” for safety of the Pfizer vaccine. .

“I think a lot of things are at stake,” said Offitt, a professor of pediatrics in the Department of Infectious Diseases at Children’s Hospital of Philadelphia. “If there is any risk of premature birth with this vaccine, I think we are going to pay a big price.

Dr. William Gruber, Pfizer’s senior vice president of clinical research and development of vaccines, told the FDA panel that “there is no conclusive evidence to suggest that the risk of premature birth is actually increasing.”

HHS’s Kim, who voted in favor of a majority of those who said yes to both safety and efficacy, was not concerned about the number of premature births considered statistically insignificant.

“I don’t think there is a clear cause-and-effect relationship between this vaccine and preterm birth. I don’t think you can rule out chance. You can’t rule out confusion over time and place.” I think,” Kim said.

“There is never complete certainty when asked to consider these themes,” said Dr. Arnold Montt, professor emeritus of epidemiology at the University of Michigan, who is a member of the committee. “This is a disease we’ve been trying to prevent for half a century, and this is the first time we’ve had the opportunity to do so with a vaccine.”

Pfizer plans a large-scale post-market safety study that will use a large database of commercial claims data, including Medicaid data, to help evaluate safety endpoints, including preterm birth, in all vaccinees. Stated.

Panel members agreed that postmarket data are important.

“Through the post-licensure data, we can let providers know to patients that this is a safe vaccine and that they have absolute confidence in protecting their infants, and I think it was clear,” said Amanda. Dr. Kohn said. She is director of the Division of Birth Defects and Infant Defects at the National Center for Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention.

A government analysis found 17 deaths in the main trial, including five in the vaccinated group and 12 in the group where mothers received a placebo.

The FDA agreed with Pfizer’s analysis that four out of five deaths in the vaccinated group were probably unrelated to the vaccine. One of the deaths was a baby born very prematurely 10 days after the mother received the vaccine, and officials said a link to the vaccine could not be ruled out.

One infant in the placebo group died of RSV infection.

next step

The only other licensed RSV vaccine is made by GSK and is for older adults. Pfizer’s RSV vaccine for the elderly is under consideration for approval.

Many pediatricians say they hope the vaccine will be approved.

“We are very optimistic that this will make RSV less of a problem in the future,” said Dr. Alexandra Yonz, an infectious disease specialist at Children’s National in Washington, DC, who said the vaccine could easily be included in routine practice. He said he believed he could be part of it. Like the TDAP vaccine, a booster that protects against tetanus, diphtheria and whooping cough (whooping cough), women are thought to be in the third trimester of pregnancy.

“Plus, mothers have the added benefit of a little boost in immunity, making them less susceptible to nasty colds,” Yonz said.

Dr. Bill Muller infectious disease specialist A professor at the Ann & Robert H. Lurie Children’s Hospital in Chicago said anything that would reduce RSV transmission would be a “welcome intervention.”

“Even just reducing the amount of disease we see would be an important advance in pediatrics,” said Mueller, who is also a professor of pediatrics at Northwestern University’s Feinberg School of Medicine.

“This could make a big difference,” he said Dr. Amy Edwards, Deputy Medical Director for Pediatric Infection Control at UH Rainbow Babies and Children’s Hospital in Cleveland. Her secret, she said, is to educate people about why they need this vaccine.

“RSV is such an underreported disease that I think it goes unnoticed unless you have a child with it or know someone in your family who has it. But any pediatrician will tell you, RSV. It’s sending as many people to the hospital and killing as many people as the flu each year,” Edwards said. “When you look at the protection that vaccines give to newborns, it’s tremendous, and you can ask any mother of a child who had to be in the ICU for RSV. I would say how much I would donate if I had this vaccine during pregnancy to protect my baby.

“If mothers are vaccinated during pregnancy, babies have a better prognosis and fewer ICU stays, it makes a world of difference.”

CNN’s Brenda Goodman contributed to this report.