According to Novavax, study data show that immunizing pregnant women with its RSV vaccine is safe and can protect infants against the virus.

The Maryland-based biotechnology company reported last month that a separate mid-stage study showed the vaccine was successful in protecting the elderly against the respiratory syncytial virus, or RSV.

RSV, which primarily affects those with compromised immune systems — including young infants and the elderly — has long eluded vaccine developers due to a lack of understanding of its molecular structure.

Novavax also said it had received a grant of up to $89 million from the Bill & Melinda Gates Foundation to support a late-stage trial testing the vaccine in pregnant women, which is planned for the first quarter of 2016.

A late-stage trial in the elderly is expected to begin later this year.