A single injection could protect babies against RSV over winter

A factory-made antibody called nirsevimab has proven safe and effective in reducing the risk of severe RSV infection in babies.

To Michael Le Paige

Parents with babies are likely to be offered antibody injections soon, around the beginning of winter. This helps protect children from respiratory syncytial virus throughout the season when RSV infections peak. There are no options to protect a healthy baby from

A trial of 3,000 infants found that a factory-made antibody called Nirsevimab (Beyfortus) was safe, with a risk of severe RSV infection requiring medical attention in infants 150 days after injection79. % has been shown to decrease. A 77% reduction in the risk of hospitalization over the same period. The results were announced at his RSV conference in Lisbon, Portugal on February 23rd.

Tonya Villafana of AstraZeneca, who led the development of nirsevimab, said: “They can get very sick.”

There’s no RSV vaccine that provokes an effective immune response in babies, and that may never happen, says Villafana. However, injecting antibodies can provide protection as long as they remain in the bloodstream.

Nirsevimab is expected to be available before next winter in the northern hemisphere, but it’s up to individual countries to approve it, Villafana said.

In older children and adults, RSV infection usually causes only cold symptoms, but in very young and very old children, the infection can be much more serious. About 100,000 children die from her RSV each year worldwide. Deaths are rare in high-income countries, but many babies require medical care for her RSV.

There is currently no licensed RSV vaccine. There is a protective antibody called palivizumab (Synagis), but it does not stay in the body for long and requires multiple injections during the RSV season. As a result, it is administered only to vulnerable babies such as premature babies. Nilsevimab has modifications that slow its breakdown in the body, so its protective effect lasts longer, Villafana says.

Nirsevimab is already approved in the EU and UK as a preventive treatment for all babies, not just vulnerable babies, based on initial results in the first 1500 babies. Other countries, such as the United States, are awaiting full trial results, Villafana said.

Full results are slightly better than initial results, so nirsevimab may now be approved in many countries around the world.

However, cost is a major issue in determining how widely Nilsvimab is used worldwide. Antibody therapies tend to be very expensive as they are difficult to manufacture and medical authorities in some countries discourage the use of nirsevimab if the cost is too high. AstraZeneca has yet to announce pricing.

Katherine Atkins of the London School of Hygiene & Tropical Medicine and her colleagues estimate that nirsevimab should cost around £60 or less per dose in the UK.

“We are calculating the highest price per dose that the UK is willing to buy nilcevimab,” said Atkins.

In low-income countries, prices will have to come down even further. In Vietnam, for example, the price should be around $5 to be cost-effective, said Lien Anh Ha Do of Australia’s Murdoch Children’s Institute.

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