A vaccine for respiratory syncytial virus (RSV) developed by Pfizer received backing from a panel of US advisers for use in people 60 and older, pushing the company to the forefront once again for immunisation against a dangerous respiratory illness.
Members of the panel that advises the Food and Drug Administration voted 7-4 with one abstention to recommend the vaccine as safe and effective in preventing RSV. But several of those who endorsed the shots also raised concerns about the lack of data on hospitalisations and the highest-risk patients, as well as two incidents of a rare disorder among those who were vaccinated.
As it did with its messenger RNA (mRNA) Covid-19 vaccine, Pfizer gained the coveted spot of being first to pass a key barrier to the US market for a lung illness that affects thousand of people each year. Pfizer has been vying with Britain’s GlaxoSmithKline (GSK) over what is estimated to become a $10 billion RSV market. GSK will face its own advisory committee hearing on Wednesday for what infectious disease specialists call the last big respiratory virus without a vaccine.
Pfizer shares rose 0.8 per cent in pre-market trading on Wednesday.
[ RSV: How to spot if your child has it and what to do if they do have itOpens in new window ]
People with weak immune systems are particularly at risk for RSV along with older people, with 177,000 hospitalisations and 14,000 deaths recorded among US elderly each year from the disease, said one 2005 study.
Ireland experienced high levels of RSV infection this winter, with babies and small children most affected, adding to pressure on GP surgeries and hospitals late last year. Those over 65 were the second largest group affected.
Children’s Health Ireland reported a 50 per cent increase in the number of children attending their emergency departments in Temple Street, Crumlin and Tallaght and the urgent care unit in Blanchardstown at the end of October last, compared to the same period in 2019, which had been their busiest year on record till then.
Pfizer and GSK have produced strong data showing the vaccines are effective in adults 60 and older, although there’s relatively little evidence on how much the vaccines reduce hospitalisations from RSV.
Several committee members raised safety questions because of two cases of a rare potential side effect among close to 20,000 trial participants who received the vaccine, which the FDA called an important potential risk before the hearing. The rare disorder, Guillain-Barre syndrome, occurs when the body’s immune system attacks the nerves, sometimes causing paralysis that is usually temporary. The syndrome has been associated with vaccination in rare cases.
“One case is a red flag, two cases is very concerning, and it’s concerning to me that Pfizer doesn’t think that there are any safety concerns,” said panel member Marie Griffin, a Vanderbilt University health policy and medicine professor.
Pfizer responded that there were confounding factors such as prior medical events that occurred in the same two patients and that the older population has higher incidences of the syndrome. The company said it would conduct a study after the drug reaches the market and is in touch with the FDA on designing it.
Other committee members said data supporting the vaccine were scant. Hana El Sahly, a Baylor College of Medicine virologist who serves as committee chairwoman, questioned why Pfizer didn’t wait until it had data for a second RSV season before applying for regulatory approval. Pfizer officials responded that data is coming shortly. Some members even requested that the vote be delayed until more data became available.
The RSV vaccine market for adults will be worth up to $10 billion by 2032, said projections by Bloomberg Intelligence. Pfizer is also facing off with collaborators Sanofi and AstraZeneca to develop prevention for dangerous RSV infections in newborns, a market that could reach $1.5 billion.
Once the FDA decides whether to go along with the advisory committee’s vote, the Centers for Disease Control and Prevention’s Advisory Committee on Immunisation Practices will issue recommendations that could have a big impact on how often the RSV vaccines are used – and how much revenue the two companies ultimately generate from them. – Bloomberg
