[Immunization to protect infants against respiratory syncytial virus disease]. For countries deciding to use a long-acting monoclonal antibody as the primary preventive strategy, WHO recommends a single dose at birth, or at the earliest opportunity thereafter if year-round administration is adopted. In a seasonal approach, administration of a single dose of a long-acting monoclonal antibody is recommended for infants and should begin shortly before the start of the RSV season, as well as at birth or the earliest opportunity thereafter for infants born during the RSV season