Pfizer’s RSV vaccine succeeds where others have failed



As parents worry about RSV cases filling children’s hospitals across the United States, finally some good news: Vaccines that protect newborns against the virus could be ready in time for next year’s season. . Pfizer Inc. today unveiled promising data on a maternal RSV vaccine that shows it reduces the risk of serious infections in babies during the vulnerable first months of life.

The early data comes with some caveats, but should be celebrated as a significant step forward in a field that has suffered decades of setbacks. It’s also an important next step in Pfizer’s goal to become a leader in the fight against RSV – a global market that Bloomberg Intelligence predicts could be worth $10 billion in 2030.

In the Pfizer trial, pregnant women received an RSV vaccine with the idea that any immunity generated would be passed on to their infants, a strategy already used for other respiratory viruses, such as whooping cough and influenza. The hope was that the protection would last for the first six months of babies’ lives, when they are most vulnerable to serious RSV infections.

The approach seems to largely work. Maternal RSV vaccine reduced the rate of severe respiratory infections by almost 82% in the first three months of an infant’s life, and by about 69% in the first six months. But the vaccine did not achieve its goal of protecting against all infections. Pfizer now plans to seek Food and Drug Administration approval for the shot, which could conceivably be ready in time for next year’s RSV season.

Full details of the study have not yet been shared, but these early results are promising, says Peter Hotez, co-director of the Center for Vaccine Development at Texas Children’s Hospital. During her career, Hotez has cared for many infants with RSV. “It’s a devastating disease,” especially for babies who have spent time in the neonatal unit or who have underlying breathing issues, he says. “We need an RSV vaccine.”

Reaching one of them proved much more difficult than the researchers had hoped. The field suffered a devastating setback in the 1960s, when infants who received an experimental RSV vaccine became significantly sicker with the virus than those who were not vaccinated. It took decades to unravel the cause of this failure and design a vaccine that could overcome the flaws of the previous vaccine.

And even with much more information about how to fight the virus, pharmaceutical companies have struggled to get to market: earlier this year, a worrying safety signal prompted GSK PLC, formerly GlaxoSmithKline, to suspend enrollment in a study of her maternal RSV vaccine. .

Given the daunting challenge, Pfizer’s success should be celebrated for making progress against a difficult virus. But it also leaves room for other products in development. Given that the vaccine has not reached the high bar of infection prevention and that some children continue to be vulnerable during and beyond this six-month window, a gap in protection still needs to be filled.

One possible solution is antibody therapy developed by Sanofi SA and AstraZeneca PLC. The single vaccine is intended to protect at-risk infants throughout an entire RSV season. In contrast, an existing antibody called Synagis, sold by the Swiss pharmaceutical company Swedish Orphan Biovitrum AB (known as SOBI), must be administered monthly.

A longer-term possibility could be to develop a booster that would help extend protection beyond infancy, Hotez says. This is a similar strategy to that used with the whooping cough vaccine – the baby is first protected by a vaccine given to the mother during pregnancy, then by injections during infancy. Pfizer, however, is not currently pursuing such a strategy.

Even with questions about whether parents and doctors will opt for a vaccine over an antibody, today’s data reinforces Pfizer’s position of ambitious leadership in the fight against the virus. The company is in a fierce race with GSK to be the first to market with a vaccine for the elderly – an equally important and far more lucrative market. Bloomberg Intelligence analyst John Murphy puts the adult RSV vaccine market at $7-8 billion, or 70-80% of the overall market for RSV products. Pfizer is also in the early stages of developing an antiviral for RSV that came about through its April acquisition of ReViral.

No matter who wins, the contest is good news for worried parents and overwhelmed hospitals.

More from Bloomberg Opinion:

• What parents can do when RSV spikes in children: Lisa Jarvis

• How to solve the Covid test data problem: Faye Flam

• We need to develop a better flu vaccine: Lisa Jarvis

This column does not necessarily reflect the opinion of the Editorial Board or of Bloomberg LP and its owners.

Lisa Jarvis is a Bloomberg Opinion columnist covering biotech, healthcare, and pharmaceuticals. Previously, she was the editor of Chemical & Engineering News.

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