Every winter, bronchiolitis is in the spotlight: its symptoms in toddlers are impressive (coughing and wheezing), although the episode is generally harmless--barring complications. This year in particular, it has been at the origin of an epidemic of unprecedented magnitude for more than ten years.

This infection of the small bronchi is most often due to a widespread and highly contagious respiratory syncitial virus (RSV).

What is much less known is that this virus also affects adults.

"When RSV is circulating, usually for five months of the year, it infects all age groups. But in people over 60, its consequences can be much more serious than in infants," Astrid Vabret, head of virology at Caen University Hospital, told AFP.

Certainly, a healthy adult who contracts the virus has a good chance of developing a common infection that resembles a cold, or even being asymptomatic. As a result, many people carry the virus and are unknowingly contagious.

However, in the elderly, the virus can lead to dehydration, breathing difficulties and more serious conditions such as pneumonia. It can also aggravate chronic conditions such as asthma, diabetes, or heart and lung disease.

"These +decompensations+ can be more or less severe. In some cases, they can lead to intensive care," says Bruno Crestani, pulmonologist at Bichat Hospital (AP-HP) and president of the Fondation du souffle.

"Limiting epidemics"

According to experts, RSV could be just as serious as the influenza virus. "The problem is that his weight is certainly very underestimated because the tests establishing his diagnosis are only done in hospitals, and again, not in all," says Professor Vabret.

While there is France surveillance of bronchiolitis in children, there is no equivalent for vulnerable adults.

"RSV is a virus that is very similar to the flu," says Christophe Trivalle, a geriatrician at Paul-Brousse Hospital (AP-HP). "Until now it was quite poorly identified but that has changed a little with Covid, which popularized PCR tests," he adds.

According to the British pharmaceutical giant GSK, the infection would lead to 270,000 hospitalizations and about 20,000 hospital deaths each year in Europe of patients aged 60 and over.

The British pharmaceutical group GSK announced that it has obtained a favourable opinion from the European Medicines Agency (EMA) for its vaccine for seniors against RSV © Fred TANNEAU / AFP / Archives

In the United States, the Centers for Disease Control estimates that RSV causes 60,000 to 160,000 elderly people to be hospitalized each year, of whom 6,000 to 10,000 die.

The situation could change with the imminent arrival of future vaccines. The British pharmaceutical group GSK announced Thursday that it has obtained a favorable opinion from the European Medicines Agency (EMA) for its vaccine for seniors against RSV.

The European Commission's final decision is expected in July 2023.

Pfizer and Moderna are each developing an RSV vaccine for the elderly, which is currently under review.

"The vaccine will be interesting for people who need it most, such as those who have an underlying disease," says Bruno Crestani. "It remains to be seen how many thousands of people will need to be vaccinated to protect against hospitalization or death," he added.

For Christophe Trivalle, the arrival of vaccines in adults is rather good news, individually, but also "to limit epidemics in communities as in nursing homes".

© 2023 AFP