Thursday, June 8, 2023
HomeHEALTHLate-stage RSV vaccine trials show 'exciting promise', some scientists say -Health

Late-stage RSV vaccine trials show ‘exciting promise’, some scientists say -Health


A Pfizer vaccine to protect older adults and children from respiratory syncytial virus (RSV) infection has shown what some scientists call “exciting” promise in late-stage trials.

a Company funded trial In adults age 60 and older, the results, published Wednesday in the New England Journal of Medicine, showed that the vaccine prevented RSV-related lower respiratory illness — including acute bronchitis and pneumonia — and RSV-related acute respiratory illness, with none Apparent security concerns.

other Company trialThe interim results of which were also published in the journal on Wednesday, the RSV vaccine was given in late pregnancy and proved to be effective against Severe RSV-related lower respiratory tract illness such as pneumonia and bronchiolitis, or inflammation of the small airway passages leading to the lungs, No safety concerns have been identified in children.

Pfizer is seeking US Food and Drug Administration approval for its RSV vaccine for older adults.

A Separate requestPfizer has asked the FDA to approve its RSV vaccine for pregnant women to protect babies. Company It said it expects a decision by August.

The FDA is also considering a monoclonal antibody treatment designed To protect children up to 2 years.

In March, the FDA’s vaccine advisors voted to approve RSV vaccine candidates from Pfizer and GlaxoSmithKline (GSK) For seniors above 60 years.

Vaccines could be world’s first if FDA commissioner agrees with advisory committee

RSV is ubiquitous. The US Centers for Disease Control and Prevention said that most children will catch this highly contagious respiratory virus before age 2.

Although RSV is a mild infection for most, for some groups, such as children and the elderly, it can cause hospitalization or death.

“When I started my residency 30 years ago, the RSV season was literally a nightmare for us in pediatrics,” said Dr. Claudia Hoenn, director of pediatric infection control at UH Rainbow Babies and Children’s Hospital in Cleveland, who was not involved in the incident. . New research.

Providers will work hard to save babies in the NICU for other reasons, she said, but when RSV season comes around, they’ll lose many of those babies.

“It was … heartbreaking,” Hoyne said.

The introduction of monoclonal antibodies to these most vulnerable children has kept RSV at bay for many, but some are still lost to the virus.

Worldwide, about 64 million people get sick from RSV each year and 160,000 die, According to the National Institute of Allergy and Infectious Diseases.

During last year’s particularly bad RSV season, some children’s hospitals had to set up tents in their parking lots to deal with the overflow of patients. But even in a typical RSV season, Hospitals are busy.

In a year, there are approximately 34 million episodes of lower respiratory tract infections associated with RSV in children under 5 years of age, and approximately 10% require hospitalization for treatment. Demonstrate research. In fact, the virus is the No. 1 reason children go to the hospital in the United States.

Thousands of older adults are hospitalized each year, according to National Foundation for Infectious Diseases.

RSV is also expensive. Every year, US spends More than $709.6 million in hospitalizations for children with RSV alone, the study found.

There is no specific treatment for RSV. Some children who are at high risk for severe disease can receive monoclonal antibodies, but this is difficult to administer and requires parents to come to the clinic at least once a month during RSV season. A vaccine would be incredibly helpful, doctors say, but trials have been stalled until recently.

In the 1960s, a disastrous RSV vaccine attempt using an inactivated virus resulted in hospitalizations of 80% of vaccinated children who later contracted RSV. Only 5% of young participants who received placebo were hospitalized.

More trials were held over the years As a scientist Worked to determine what went wrong. Meanwhile, the U.S. government has built more fences to make clinical trials safer going forward.

A decade ago a research team at National Institutes of Health Figure out a core mechanism of the virus. Scientists can develop safer vaccines based on that knowledge that can detect when the virus invades the body and trigger the body to develop stronger defenses against it.

Until recently, four companies had RSV vaccines for seniors in the final stages of trials.

Johnson & Johnson’s Vaccine Division, Janssen, was far away. But at the end of March, the company made such an announcement It was abandoned its candidate.

J&J said the vaccine was lost in the company’s “larger effort to make strategic choices about its pipeline and research and development (R&D) investments to focus on drugs with the greatest potential benefit to patients.”

that leaf Bavarian Nordic Another company focuses on a vaccine for the elderly, for example. Its trial results are expected in the middle of this year.

When the FDA’s independent vaccine advisers voted to recommend that the agency approve Pfizer and GSK’s vaccines for seniors, the companies showed promising data.

GSK’s RSV vaccine candidate for older adults was 82.6% effective in preventing lower respiratory tract infections, a company funded Research published in NEJM The shot was 94.1% effective in preventing severe disease in February.

For Pfizer’s vaccine for people age 60 and older, Wednesday’s study showed 66.7% effectiveness against RSV-associated lower respiratory tract illness with two or more signs or symptoms and 85.7% vaccine effectiveness against RSV-associated lower respiratory tract illness with three or more. with more symptoms.

The study found that there was not enough incidence of severe RSV-related lower respiratory tract illness, meaning hospitalization or the need for ventilation or supplemental oxygen, to achieve that effect.

One reason may be that the tests were conducted during the Covid-19 pandemic, when there weren’t as many RSV cases as usual, said Dr. Anne Falsey.

“The event rate was low. So, for that reason, they couldn’t just say it reduced hospitalizations, but in my mind, anything that prevents ARIs, respiratory infections, and lower respiratory tract infections would obviously lead to fewer hospitalizations. It makes a lot of sense, but they haven’t proven it,” said Folsey, who was involved in the new study and cares for elderly RSV patients. He is Professor of Medicine at the University of Rochester School of Medicine.

According to the study, the Pfizer vaccine was considered safe.

in 20,000 recipients At trial, there was a case Guillain-Barre syndromeA rare disorder in which the body’s immune system attacks the nerves a week after vaccination. Company documents Show that the case was considered life-threatening, but there may have been a complicating factor, as the person had a heart attack the day before doctors referred Guillain-Barré.

It also had a lawsuit Miller-Fisher syndrome, another rare neurological disorder considered a variant of Guillain-Barré. This person developed the disease eight days after vaccination but recovered about a month and a half later.

During the discussion of the independent FDA advisers about the vaccine, Dr. attack El Sahli, chairman of the committee and professor of virology at Baylor College of Medicine, said the two cases put the rate of the condition at about 1 in 9,000, far higher than what is seen in the general population.

One person in the GSK trial also developed Guillain-Barré nine days after receiving the vaccine and spent six months in rehabilitation. The FDA considers the case possibly vaccine-related.

If vaccines are approved, doctors say, it will be important to monitor their safety.

Interim results for Pfizer’s vaccine for children show the candidate did not meet the company’s criteria, again likely because the trial was conducted during the pandemic, when RSV cases were low. However, research is ongoing.

an editorial In addition to Wednesday’s research published by Dr. “It is noteworthy that the efficacy against severe RSV-associated lower respiratory tract illness was 81.8% at 90 days after birth and 69.4% at 180 days after birth,” says Ruth Caron. In other words, it didn’t necessarily prevent infections, but it kept them from getting worse.

Caron is a professor in the Department of International Health and director of the Center for Immunization Research at the Johns Hopkins Bloomberg School of Public Health. Johns Hopkins Vaccine Initiative— who was not involved in the new study — wondered in the editorial whether this era of RSV vaccine development could be the “beginning of the end” of massive RSV outbreaks.

Another study Published in NEJM on Wednesday, nirsevimab, a monoclonal antibody to prevent RSV developed by AstraZeneca and Sanofi, has been approved by the European Commission and the UK to prevent children from getting sick with RSV.

The companies have sought FDA approval to use the treatment to protect children up to age 2.

This study found that 150 days after injection, the efficacy of hospitalization for RSV-associated lower respiratory tract infections was 76.8%, and the efficacy against very severe treatment-emergent RSV-associated lower respiratory tract infections was 78.6%.

Finally, in term infants and in late preterm infants, a single dose provides protection against hospitalization with RSV.

Hoyen thinks it will take a monoclonal antibody treatment as well as a vaccine to protect children. Many pregnant women do not get vaccinated; At most, only 57% to 61% of pregnant women get shots to protect against flu and tetanus-diphtheria-acellular pertussis. A 2020 study from the CDC.

“We try, but overall, we don’t do a very good job of vaccinating mothers when they’re pregnant,” Hoenn said.

Now, the government will decide how these vaccines and treatments will be used. Scientists will also look at how long the vaccine provides protection during the next RSV season.

Even with all these precautions, health care providers who treat people with RSV say it’s incredible news.

“I am incredibly happy with all these results. You know, for someone who’s been working in the field for over 30 years, it’s very satisfying to see both a vaccine for children and a vaccine for older adults. It’s horrible,” Falsey said.

Dr. William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center and medical director of the National Foundation for Infectious Diseases, said such a vaccine could be a huge public health boost.

“RSV is a huge problem, especially for children but also for adults. RSV can cause influenza-like illness in at least some years,” said Schaffner, who was not involved in the new research. “These are exciting potential advances. We will see their development as several products come to maturity and come before the Food and Drug Administration for licensure this year or next. It’s going to be an exciting time.”



Please enter your comment!
Please enter your name here

Most Popular

Recent Comments