The attention for Covid-19 had made him overshadow a bit in the public eye, but the respiratory syncytial virus (RSV) remained a threat to the health of the little ones. And now, thanks to the easing of coronavirus prevention measures, infections are returning to pre-pandemic figures. Soon, however, we may have an extra weapon to protect newborns from this virus, which can cause lower respiratory tract infections and lead to bronchiolitis and pneumonia: the monoclonal antibody nirsevimab has been shown to reduce by 74 with a single intramuscular injection. , 5% the use of medical assistance. The results of the phase 3 study are published in the British Journal of Medicine.
The experiments
The results described are those that emerged from the Melody and Medley trials.
In particular, the phase 3 Melody study, which involved 1,490 healthy infants born at full term or in any case after the 35th week, achieved its primary objective, namely the reduction of the incidence of medical assistance needed in case of lower tract infections. of the airways caused by Rsv: – 74.5% compared to placebo. A protection that was obtained with a single intramuscular administration of monoclonal antibody and which was maintained over time, covering the entire first season of children’s Rsv.
The phase 2/3 Medley study, on the other hand, allowed to evaluate the safety and pharmacokinetic characteristics of nirsevimab in newborns with congenital heart failure, chronic pulmonary insufficiency and in premature babies, demonstrating a profile comparable to that of palivizumab, another monoclonal antibody directed against RSV, which is used to protect high-risk infants and is administered intramuscularly once a month throughout the season of RSV infections. The levels of nirsevimab found in the blood of infants 151 days after administration are also similar to those found in the Phase 3 study in healthy infants, suggesting that the protection provided is similar across populations.
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A paradigm shift
Nirsevimab is therefore the first monoclonal antibody, designed for a single administration and to have a long-lasting effect, which is proving to be safe and effective in protecting all newborns from the consequences of an Rsv infection. A milestone on the road to preventing this virus.
In this direction, then, it should be remembered the effort of Moderna which at the end of February announced that it had started studies at an advanced stage on its mRna vaccine against respiratory syncytial virus, after having received a positive evaluation of the tolerability results on the elderly, who, like newborns, are more vulnerable to severe infections.