Maternal vaccination offers a promising solution to RSV bronchiolitis. Different companies are developing maternal RSV vaccines. For example, Novavax has successfully used a nanoparticle-based RSV-F vaccine in a phase 2 trial in women of child bearing age. The potential efficacy of maternal vaccination is now beautifully shown by Madhi and colleagues showing that maternal vaccination may be effective to prevent severe infectious diseases during infancy.
In a large influenza trial, maternal vaccination with a trivalent inactivated influenza vaccine was about 50% protective against influenza disease in 2116 pregnant women and their babies up to age 24 weeks. A parallel trial in HIV positive pregnant women was performed. Infants of HIV positive mothers showed higher rates of influenza, but vaccine efficacy was reduced to 27%.
This study is relevant to the development of a maternal RSV vaccine, because it provides proof of principle that such a strategy in low income countries may be quite successful. For infants from HIV positive mothers, also those who are born HIV negative, other strategies are required.