Palivizumab is given monthly during the winter season to infants at high risk of severe bronchiolitis. Its protective effect depends on neutralizing which viral component?

• A The G attachment glycoprotein of respiratory syncytial virus
• B The pentamer base of human metapneumovirus
• C The hemagglutinin-neuraminidase of parainfluenza virus type 3
• D The F fusion glycoprotein of respiratory syncytial virus ✓

Explanation

Palivizumab is a humanized monoclonal antibody directed against an epitope on the F (fusion) glycoprotein of RSV, preventing membrane fusion and syncytium formation. The same antigen is now targeted by nirsevimab, a longer-acting extended-half-life monoclonal. Distractor A names the G attachment protein, which mediates binding but is not the palivizumab target. Prophylaxis reduces hospitalization severity in premature infants and those with congenital heart or lung disease but does not treat established infection.

Reference: Nelson Textbook of Pediatrics, 22nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.