The World Health Organization on Tuesday recommended vaccinating pregnant women and passing the antibodies to infants to prevent severe respiratory syncytial virus (RSV) infection in newborns.

RSV, which typically causes cold-like symptoms, is a leading cause of serious infection and death in infants and older adults. According to WHO, most RSV-related deaths occur in low- and middle-income countries, with approximately 101,400 annual deaths of children under five years of age.

WHO recommends giving pregnant women a single shot in the third trimester, which usually starts at 28 weeks, to protect their babies.

Pfizer’s RSV shot, sold as Abrisvo, is the only vaccine available in the United States and Europe for use in pregnant women. It has also been approved in some other markets such as Japan and Canada.

For infants and children, Sanofi and AstraZeneca’s antibody, Beaufort, is again the only approved shot in the United States, the United Kingdom and some other countries — but supplies of it are limited.

The manufacturers recently received approval from the US Food and Drug Administration for an additional manufacturing line for Befortus.

WHO’s strategic advisory group noted concerns around the supply and high cost of antibodies, saying this could severely limit global access and equity for treatments.

“We are looking forward to more products entering the market to allow global access and increase equity to use these products,” said Hannah Nohnek, chair of WHO’s Strategic Advisory Group on Immunization.

This time as the WHO advisory group focused on children, Nohneek said he had received requests from several countries about recommendations for the elderly.

WHO executive Joachim Hombach said there were challenges in implementing the recommendations for older adults, because many countries did not have vaccination programs for that age group.