Medicine against children’s RSV is 76% effective – 06/03/2023 – Health

Final results of a global trial of the efficacy of nirsevimab for the prevention of respiratory syncytial virus (RSV) infection and hospitalization indicate protection of up to 80% in infants up to two years of age.

For prevention against hospitalization, the result of the study indicated a protection of 76%, 14 percentage points more in relation to the preliminary data presented in March 2022, of 62.1%.

The evaluation included healthy preterm infants up to 2 years of age, with a gestational age at birth of 35 weeks or more, in their first season of contact with RSV.

RSV is the main causative agent of bronchiolitis in infants, a common and highly contagious respiratory disease whose main symptoms are cough and shortness of breath. In general, cases of the disease are mild, but may result in hospital admissions.

In September last year, nirsevimab obtained a favorable opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency.

Nirsevimab is a monoclonal antibody that prevents the virus from entering cells. The drug was developed in partnership by pharmaceutical companies AstraZeneca and Sanofi.

So far, the only medicine available against the virus was palivizumab, produced by the pharmaceutical company AstraZeneca, indicated only for severe cases of respiratory infections, with a high risk of hospitalization.

The research was initially aimed at evaluating 3,000 babies with a gestational age of 35 weeks or more, but it was stopped due to the restriction measures imposed by the Covid pandemic. At that point, about 1,490 babies had been included in the study, but the secondary endpoint analysis, ie, protective capacity against hospitalization, was lower than expected at 62.1%.

“After the Covid restrictions were relaxed, we resumed the study, enrolling another 1,522 babies, which led to the presented results of efficacy of 76.4%, against respiratory infection, and 76.8% for hospitalization”, said the global director of innovation at Sanofi, Jon Heinrichs.

According to him, the larger sample size allowed for a more accurate analysis of the drug’s effectiveness. “Nirsevimab is designed to be given to all babies and, as our studies indicate, reduces respiratory infections requiring medical attention in both inpatients and outpatients,” he said.

The drug is promising because it may represent a good option for protection in healthy babies, with no apparent risk of hospitalization.

In the phase 3 study, named Melody, the drug was nearly 80% effective for the risk of needing medical care for a respiratory infection.

Experts claim that, after Covid, the seasons of common respiratory viruses in childhood changed, which have caused out of season outbreaks of RSV and other etiological agents, such as rhinovirus and influenza.

In January of this year, hospitals in São Paulo, Minas Gerais and Paraná showed an increase in cases of hospitalization due to RSV, unusual for the time of year.

In recent weeks, Sabará Children’s Hospital has seen an increase in demand and positive results for the so-called respiratory panel in children treated at the unit.

Until the last day, February 18, 57 tests were carried out, of which 49 were positive for a virus (86% positivity). In the week that ended on the 25th, there was a small drop in positive results, from 41 out of 48 tests performed (85%). Of these, seven or 13% were RSV positive.

According to pediatricians, the lack of contact in the early years of the pandemic with other children may have caused a delay in building the immunity of the little ones, which caused new outbreaks to appear when the pandemic restriction measures were lifted.

Although most cases of bronchiolitis pass within a few days, in premature babies or with pre-existing health conditions, the infection can lead to complications.

Globally, in 2019, approximately 33 million cases of RSV respiratory infection with more than 3 million hospitalizations were recorded, leading to more than 26,000 hospital deaths in children under five years of age.