End-stage studies show that vaccination of AZ/Sanofi reduces the risk of children hospitalized with RSV by 75%

Babies could soon receive a vaccine that lowers their risk of contracting respiratory syncytial virus (RSV), scientists announced last night.

A sting performed by AstraZeneca and French company Sanofi was found to reduce hospitalizations by two-thirds in children under the age of one.

The Nirsevimab vaccine is given as a single dose and protection lasts five months – a full RSV season.

The results of the Phase 3 studies were described as a “paradigm shift” by experts who conducted the studies.

Despite decades of research, there is currently no vaccine available for the general population.

An injection known as palivizumab is offered to high-risk infants in the UK but offers only one month of protection, meaning infants need five shots to cover a season.

RSV causes coronavirus-like symptoms and is a leading cause of infant admissions in the UK.

It is responsible for 29,000 hospital admissions and 80 deaths per year in children under five in the UK and 58,000 admissions and 500 deaths in young people in the US.

Young children could soon receive a vaccine that lowers their risk of contracting respiratory syncytial virus (camp)

The Nirsevimab vaccine was 74.5 percent effective in preventing children from getting RSV to the point where they needed medical attention. The graphs show the proportion of vaccinated children who did not seek medical care because of RSV virus (yellow) compared to the unvaccinated (blue). The internal chart shows the same data but on a larger vertical axis

Phase 3 clinical trials of the RSV vaccine enrolled 1,490 healthy children in the US and South Africa, aged one year or younger, entering their first RSV season, which lasts from October to March in the UK.

Two-thirds of the infants received the nirsevimab vaccine, while one-third received a placebo vaccine.

Nirsevimab is a long-acting monoclonal antibody vaccine that involves injecting proteins that have been prepared in a lab to already fight the virus.

It does not require activation of the immune system, which can take weeks with normal vaccines, and provides fast and direct protection against disease.

The results, published in the New England Journal of Medicine, show that 12 infants (1.2 percent) given the vaccine required medical attention for respiratory viruses caused by RSV.

Meanwhile, 25 children (5 percent) in the unvaccinated group had to see a doctor, four times more than the vaccinated cohort.

Hospital admission rates were almost three times higher in the unvaccinated group (1.6 percent) compared to the vaccinated children (0.6 percent).

Researchers at the Stanley Manne Children’s Research Institute in Chicago, who are conducting the studies, said the results show the vaccine is 74.5 percent effective at preventing adolescent hospitalizations.

About a year after enrollment in the study, 6.1 percent of vaccinated children had RSV antibodies, compared with 1.1 percent of unvaccinated adolescents.

Side effects were seen in 6.8 percent of those who received the nirsevimab vaccine and 7.3 percent of those who received the placebo, but most were mild or moderate, including pain at the injection site.

The fact that the side effect rates were about the same meant the vaccine was safe.

dr William Muller, Principal Investigator of the study and Scientific Director of Clinical Trials at the Institute, said: “These exciting data show that nirsevimab has the potential to provide RSV protection for all infants, which would represent a paradigm shift in the approach to this disease.

“We know RSV has seen a resurgence with the easing of Covid public health measures.

This tells us that a comprehensive immunization approach is needed to reduce the significant global burden that RSV poses to infants, their families and health services.’