As part of the seminar series titled “A New Era in RSV Prevention with Monoclonal Antibodies for All Infants”, held in Ho Chi Minh City and Hanoi in early October 2025, experts emphasized the importance of proactively preventing lower respiratory tract infections caused by Respiratory Syncytial Virus (RSV) in all newborns and infants under 12 months of age through the use of long-acting monoclonal antibodies.

The seminars, held on October 2 and 3, 2025, were organised by the Tam Anh Research Institute with sponsorship from Sanofi Aventis Vietnam Co., Ltd., a subsidiary of the French pharmaceutical group Sanofi. Experts focused on updating and discussing the disease burden of RSV in infants, current prevention strategies, and highlighted the protective efficacy of the long-acting monoclonal antibody Nirsevimab in reducing hospitalizations due to lower respiratory tract infections (including bronchiolitis and pneumonia) in newborns and infants.

According to experts, RSV is the leading cause of lower respiratory tract infections such as bronchiolitis and pneumonia that require hospitalization in young children. Infected infants may develop complications such as respiratory failure, requiring oxygen therapy, mechanical ventilation, or intensive care. Nearly 70% of infants under 12 months of age contract RSV during their first year of life. Physicians cannot accurately predict which infants will develop severe disease. Data from international studies and major pediatric hospitals in Vietnam show that 70–90% of infants hospitalized for RSV-related lower respiratory tract infections were full-term and previously healthy. RSV symptoms often begin mildly with cough, sneezing, nasal discharge, and irritability, but may progress to high fever, feeding refusal, rapid breathing, chest retractions, cyanosis, respiratory failure, and death. Furthermore, infants infected with RSV during the first year of life may face increased risks of persistent wheezing, otitis media, or asthma in subsequent years.

Therefore, proactive prevention is critically important to protect the health of all infants from birth.

Discussing RSV prevention strategies, Dr. Khanh Huu Truong, Vice President of the Ho Chi Minh City Infectious Diseases Society, stated that the long-acting monoclonal antibody Nirsevimab has been approved by the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and numerous countries worldwide, and is recommended for use to protect newborns and infants from the significant disease burden caused by RSV.

RSV prevention strategies demonstrate that immunizing all infants with the long-acting monoclonal antibody Nirsevimab effectively prevents the majority of lower respiratory tract infections requiring medical care, including both inpatient and outpatient treatment.

“Nirsevimab provides rapid and direct antibody protection with a long duration of action. A single dose can protect infants throughout their first year of life. This is considered an advanced solution to effectively protect newborns and infants from serious complications caused by RSV, including pneumonia and bronchiolitis,” Dr. Khanh added.

Dr. Chinh Thi Bach, Medical Director of VNVC Immunization System, stated that Nirsevimab has been approved in 56 countries, including Vietnam, and is recommended for use in infants by numerous medical associations worldwide. It is the first RSV prevention solution developed and studied across diverse infant populations, including preterm infants, those with underlying conditions, and healthy full-term infants.

“Nirsevimab allows physicians to flexibly choose the timing of administration and can be given as early as immediately after birth. It can be co-administered with other pediatric vaccines. Studies show that Nirsevimab has high viral neutralization capacity and does not depend on the maturity of the infant’s immune system, thereby providing effective protection for all infants during their first RSV season and for high-risk infants during the second season”, Dr. Chinh explained.

Prof. Dr. Chau Quy Ngo, Deputy General Director for Medical Affairs and Respiratory Advisor at Tam Anh General Hospital in Hanoi, stated that RSV causes a significant annual disease burden, affecting the healthy and comprehensive development of infants during their first year of life. There is currently no specific antiviral treatment for RSV, management is primarily supportive to alleviate symptoms. Public awareness of RSV remains low, resulting in missed opportunities for early disease prevention. Therefore, enhanced communication and counseling from healthcare professionals are essential.

Professor Chau emphasised: “Providing immunity from birth with the long-acting monoclonal antibody Nirsevimab is a novel approach that helps reduce hospitalizations and mortality due to RSV-related respiratory illness, while conserving healthcare resources for families, the health system, and society at large”./.