Paediatricians’ blood used to make new treatments for RSV and colds

In the fight against common childhood illnesses, scientists have turned to an unusual source: the blood of paediatricians. It turns out this is a treasure trove of powerful antibodies that could be used as preventative treatments. These have even outperformed approved antibody therapies against respiratory syncytial virus (RSV) and a common cold virus.

Paediatricians are almost constantly exposed to respiratory viruses, making them a potentially underexplored resource in the hunt for highly potent antibodies against such pathogens. Although antibody therapies are available for infections like RSV – which infects almost every child by the age of 2 and can trigger severe breathing difficulties – they only neutralise some strains. But a broader-acting treatment could now be on the cards.

A team including Hui Zhai at the Children’s Hospital of Chongqing Medical University screened the blood of 10 paediatricians who had been working at the hospital for over a decade. From this, the researchers discovered 56 potent antibodies against RSV from the paediatricians’ immune cells.

The researchers then generated artificial versions of these antibodies and tested them in the lab, finding that three were particularly active against a diverse range of RSV strains. One of the three also neutralised human metapneumovirus, which belongs to the same virus family as RSV and is a common cause of colds, but can also lead to severe illness in some children.

Subsequent tests in mice and rats showed that injections of these three paediatrician-derived antibodies, either on their own or in combination, stopped the animals from developing symptoms when they were infected with RSV or human metapneumovirus. In fact, the paediatrician antibodies were up to 25 times better at blocking RSV than existing antibodies called nirsevimab and clesrovimab, and they neutralised a wider range of strains.

This makes sense because it is common lore among paediatricians that they become increasingly resilient to respiratory viruses over the course of their careers, says Trent Calcutt at Port Macquarie Base Hospital in Australia. “I’ve been working with paediatric patients for 10 years now and in my first few years, I would probably get two to three notable respiratory illnesses per year, and now I can go a year without getting any.”

Calcutt believes the paediatrician-derived antibodies appear promising enough to warrant further testing in human clinical trials. “There are certainly stranger interventions out there, so I think this one is worth considering,” he says.

Currently, there are two ways to protect infants from RSV. One is to administer a vaccine during pregnancy, which protects babies once they are born. The other is to give them an injection of nirsevimab or clesrovimab, which neutralise the virus if a child catches it, thereby helping to prevent severe symptoms. But these only work against some RSV strains.

Nirsevimab and clesrovimab were similarly developed by screening the blood of adults who had previously been infected with RSV. This identified antibodies that the individuals’ immune systems had naturally produced against the virus. There is no approved vaccine or antibody therapy for human metapneumovirus.