Warning 2025: RSV Lurking Around Newborns—Expectant Mothers Need Vaccination to Protect Their Babies!

Respiratory Syncytial Virus (RSV) is a virus that causes serious respiratory illness in infants worldwide, including in Vietnam. RSV is a major cause of severe respiratory tract infections in young children. In Vietnam, RSV commonly causes bronchiolitis and pneumonia in children [1, 2, 4].

• Why are infants particularly susceptible to RSV?

Immature immune systems

Infants, particularly premature babies and those with underlying medical conditions, have immature immune systems. This makes it more difficult for their bodies to fight RSV, increasing the risk of severe illness and complications [5, 6].

Small and sensitive airways

Infants have very small airways. When the airways become inflamed due to RSV infection, they can become swollen and blocked by mucus, making it difficult for the baby to breathe [3].

• Many children are hospitalized with RSV in Vietnam

A study conducted at Hai Phong Children’s Hospital in 2016–2017 found that hospital admissions for RSV-associated bronchiolitis increased during the winter–spring season, from October to March [1]. Another study conducted at Children’s Hospital 2 in Ho Chi Minh City in 2010–2011 detected RSV in nearly 24% of respiratory specimens from children with acute respiratory infections [4]. The study also found that younger children tended to develop more severe RSV disease [4].

• Is RSV dangerous for infants?

  Early symptoms can be mistaken for other respiratory illnesses:

Initially, RSV infection in infants may resemble a common cold, with symptoms such as a runny nose, mild cough, and low-grade fever. However, the illness can progress rapidly in young children [3].

RSV can cause bronchiolitis (inflammation of the small airways in the lungs) and pneumonia (lung infection). In such cases, infants may develop severe symptoms such as rapid breathing, wheezing, chest retractions, nasal flaring, pale skin, or bluish discoloration [3, 5].

Risk of hospitalization and death:

RSV is one of the most common causes of hospitalization among infants [7]. Worldwide, more than 3.6 million children under 5 years of age are hospitalized and approximately 100,000 children die from RSV each year. Half of these deaths occur in children younger than 6 months [2]. In Vietnam, many cases of severe RSV infection require mechanical ventilation or may lead to serious complications [1, 2, 6].

Acute lower respiratory infection (ALRI) is a leading cause of death among children under 5 years of age worldwide [8]. In Vietnam, ALRI accounted for approximately 13% of deaths among children under 5 in 2017 [9]. RSV is a major cause of ALRI in southern and central Vietnam [9].

A 2023 study in southern Vietnam found that the average cost of one hospitalization for RSV-associated lower respiratory tract infection (LRTI) in children was USD 165 [9]. This cost may account for 32% to 70% of the monthly minimum wage of an individual in Ho Chi Minh City. These findings highlight the substantial economic burden of RSV on Vietnamese families.

• RSV Vaccine for Pregnant Women: A “Shield” to Protect the Baby

RSV vaccination during pregnancy is an effective way to protect newborns. When a pregnant woman receives the vaccine, her body produces antibodies against RSV. These antibodies cross the placenta to the fetus, providing passive immunity from birth and during the first few months of life—the period when infants are most vulnerable [2, 7].

Maternal RSV vaccination has been shown to significantly reduce the risk of severe RSV disease in infants. According to the WHO, the first maternal RSV vaccine was prequalified in March 2025 to protect infants [2]. This vaccine reduces the risk of severe RSV disease and RSV-related hospitalization in young infants [7].

• When is the best time for pregnant women to receive the RSV vaccine?

The World Health Organization (WHO) recommends that pregnant women receive the vaccine from 28 weeks of pregnancy onward to facilitate the transfer of a greater amount of antibodies to the fetus [2].

• What should pregnant women do?

If you are pregnant or planning to become pregnant, learn about the RSV vaccine and discuss it with your physician. Your doctor will provide specific advice and assess whether the vaccine is appropriate for you based on your health status and the latest medical recommendations.

• Are there other ways to prevent RSV infection in infants?

In addition to vaccination, parents should take the following measures to help protect infants from RSV:

• Wash hands frequently with soap.
• Avoid close contact with people who are sick.
• Cover your mouth and nose when coughing or sneezing.
• Avoid taking infants to crowded places, particularly during periods of increased disease transmission.
• Keep the home clean.

What should you do if your baby shows signs of illness?

If an infant develops any signs of RSV infection, such as difficulty breathing, wheezing, high fever, poor feeding, or unusual fatigue, the baby should be taken to a hospital immediately for timely evaluation and treatment.

1. Editorial Review Information & References

Medical consultation: [To be updated]
Last updated: November 15, 2025

1.1. References

[1] Nguyen SN, Nguyen TNT, Vu LT, Nguyen TD. Clinical Epidemiological Characteristics and Risk Factors for Severe Bronchiolitis Caused by Respiratory Syncytial Virus in Vietnamese Children. Int J Pediatr. 2021;2021:9704666. Published November 15, 2021. doi:10.1155/2021/9704666. Accessed November 15, 2025.

[2] WHO. (2025). WHO prequalifies first maternal respiratory syncytial virus vaccine. www.who.int/news/item/19-03-2025-who-prequalifies-first-maternal-respiratory-syncytial-virus-vaccine. Accessed November 15, 2025.

[3] WHO. (2025). WHO outlines recommendations to protect infants against RSV – respiratory syncytial virus. www.who.int/news/item/30-05-2025-who-outlines-recommendations-to-protect-infants-against-rsv-respiratory-syncytial-virus. Accessed November 15, 2025.

[4] DN Tran. (2013). Molecular epidemiology and disease severity of human respiratory syncytial virus in Vietnam. pubmed.ncbi.nlm.nih.gov/23349659/. Accessed November 15, 2025.

[5] Mayo Clinic. (N/A). Respiratory syncytial virus (RSV) – Symptoms & causes. www.mayoclinic.org/diseases-conditions/respiratory-syncytial-virus/symptoms-causes/syc-20353098. Accessed November 15, 2025.

[6] WHO. (N/A). Respiratory syncytial virus (RSV). www.who.int/news-room/fact-sheets/detail/respiratory-syncytial-virus-(rsv). Accessed November 15, 2025.

[7] CDC. (2025). RSV Immunization Guidance for Infants and Young Children. www.cdc.gov/rsv/hcp/vaccine-clinical-guidance/infants-young-children.html. Accessed November 15, 2025.

[8] Ali Alsuheel Asseri. (2025). Respiratory Syncytial Virus: A Narrative Review of Updates and Recent Advances in Epidemiology, Pathogenesis, Diagnosis, Management and Prevention. pmc.ncbi.nlm.nih.gov/articles/PMC12156131/. Accessed November 15, 2025.

[9] Do LAH, Le NTN, Mahmud S, Mulholland K, Pecenka C, Clark A. Impact and cost-effectiveness of strategies to prevent respiratory syncytial virus (RSV) disease in Vietnam: A modelling study. Vaccine. 2023;41(46):6782–6790. doi:10.1016/j.vaccine.2023.09.003. Accessed November 15, 2025.

The information provided above is for reference purposes only and does not constitute medical advice or a recommendation. Please contact your physician for detailed consultation.