Human metapneumovirus prevention in children: emerging roles of monoclonal antibodies and vaccines.

Human metapneumovirus (hMPV) is a major cause of acute lower respiratory tract infection in children, older adults, and individuals with underlying medical conditions. In pediatric populations, hMPV contributes substantially to hospitalizations, morbidity, and healthcare costs, yet no licensed vaccine or monoclonal antibody is currently available for prevention. This narrative review summarizes current evidence on emerging preventive strategies against hMPV, with particular emphasis on monoclonal antibodies (mAbs) and vaccines for children. Advances in structural virology have identified the fusion glycoprotein as the principal target of neutralizing immunity and have provided a rationale for the development of hMPV-specific and cross-reactive RSV-hMPV mAbs. Several mAbs have shown potent neutralizing activity and protection in animal models, although clinical development remains limited. Vaccine development has progressed across multiple platforms, including live-attenuated, mRNA, protein-subunit, virus-like particle, and viral-vectored vaccines. However, key challenges remain, particularly regarding immunogenicity in seronegative infants, risk of enhanced respiratory disease, durability of protection, seasonality, and optimal target populations. Current evidence suggests that hMPV prevention in children will likely require a layered strategy combining maternal immunization, active vaccination during late infancy, and targeted protection for high-risk children beyond infancy.