La Bronchiolitis remains one of the leading causes of hospital admission. in babies under one year old, especially during the colder months. For this reason, various health authorities are strongly promoting Respiratory Syncytial Virus (RSV) vaccination campaign, the main culprit behind this respiratory infection in early childhood.
In the case of Spain and other European countries, this strategy is based on the experience accumulated in territories such as the province of Buenos Aires, where maternal vaccination against RSV was incorporated into the public schedule and has shown that It clearly reduces severe cases of bronchiolitis in the first months of life.The available data shows a decrease of nearly 20% in reported cases in children under six months old after the campaign was launched.
A campaign focused on pregnant women from 32 to 36 weeks
The key element of this strategy is the vaccination of pregnant people at a very specific stage of pregnancyBetween weeks 32 and 36 inclusive. During this period, the mother's body can generate antibodies against RSV that will reach the baby through the placenta, so that the newborn is born with a level of protection against severe forms of the infection.
According to health authorities, the vaccine It is not administered directly to the baby.Instead, it is administered to the pregnant woman, and it is the mother's own body that transfers the immunity. In this way, infants are protected during the stage when they are most vulnerable, especially during the first six months, when the virus can cause bronchiolitis or pneumonia that require hospitalization.
The campaign is aimed exclusively at women who are in that stage of pregnancy, as well as those who reach that stage during the virus's circulation season. In areas where it is already being rolled out, the vaccine is offered in a Free and without the need for special authorization., in the same way as other immunizations recommended during pregnancy.
In contexts like Buenos Aires, the campaign has relied on a broad network of vaccination sites. There, for example, the vaccine is available in more than 1.800 vaccination centers and primary care centersin addition to public clinics and hospitals. This model is similar to the one proposed in Europe, using health centers and maternity wards as the main entry point.
In municipalities like 9 de Julio, vaccination is offered at the Primary Health Care Centers (CAPS)From Monday to Friday, on a continuous schedule and on a first-come, first-served basis, which allows pregnant women to come without an appointment as long as they can prove they are between weeks 32 and 36.
Reduction in severe cases and concern about low coverage
The figures provided by the surveillance systems show that the The RSV vaccine during pregnancy is already having a tangible impact in childhood bronchiolitis. In the province of Buenos Aires, for example, cases in children under six months of age dropped from almost 25.000 to less than 20.000 in one year, representing a reduction of nearly 20% in this age group.
The records detail that, between 2024 and 2025, the number of diagnoses in very young babies decreased from 24.932 to 19.943. This The significant drop coincides with the first two years of the vaccine's inclusion in the schedule. of immunization during pregnancy, and adds to the general downward trend in severe forms requiring hospitalization.
Even so, public health officials insist there is room for improvement. Campaign coverage remains below desired levels. less than 70% of eligible pregnant women are reachedEstimates range around 68% vaccination coverage in the target population, a figure that leaves a significant number of newborns without that additional protection during the months of highest virus circulation.
This gap is worrying because, as experts point out, Respiratory infections continue to be among the leading causes of infant mortalityAccording to data handled by health authorities, respiratory diseases represent the third leading cause of death in childhood and the second leading cause in the post-neonatal period, that is, after the first month of life.
Given this scenario, the appeal to pregnant women is being intensified, especially those nearing the end of their pregnancies in the middle of winter. Communication campaigns emphasize that get vaccinated during pregnancy It increases protection for the newborn, and not getting vaccinated during pregnancy increases the risk of the baby developing severe bronchiolitis or pneumonia if infected with RSV in its first weeks of life.
How the Respiratory Syncytial Virus vaccine works
Respiratory Syncytial Virus is the main cause of acute respiratory infections in infants and young children. In most cases, the symptoms resemble those of a common cold, but in children under one year old—and especially in those under six months—it can affect the lower respiratory tract and trigger bronchiolitis or pneumonia.
Maternal immunization aims to anticipate this risk. By vaccinating the pregnant person between weeks 32 and 36, the body produces specific antibodies against RSVThese antibodies cross the placenta and reach the fetus, so the newborn has immediate protection when the virus circulation intensifies, usually in autumn and winter.
It is worth emphasizing that the vaccine It does not completely prevent the spread of the virusRather, it primarily reduces the likelihood of the infection progressing to severe forms requiring hospitalization, oxygen therapy, or other intensive care. In other words, the goal is to decrease complications and deaths, rather than prevent all mild cases.
The strategy of vaccinating during pregnancy complements other well-established public health measures, such as childhood vaccination against other respiratory infections (e.g., pneumococcal disease) or maternal immunization against pertussis and influenza. With this combined approach, a broader protective shield is created around the newborn, a particularly vulnerable group.
Sources from immunization programs highlight that maternal vaccination allows to effectively protect infants under six months without needing to directly puncture the babyThis approach is especially useful in the first few months of life, when childhood vaccination schedules are just beginning and the child's immune system is immature.
Warning signs and sounds in bronchiolitis
Recognizing the symptoms of bronchiolitis early on is crucial for seek timely medical attentionOne of the most characteristic signs is a whistling sound in the baby's chest, a noise that usually catches the attention of families because it is not the typical sound of a mild cold.
Along with that whistle, the creature may show difficulty breathing and visible effort when inhalingIn the most severe cases, the ribs sink in when inhaling, bronchial noises are noticeable, and the baby becomes easily agitated. They often have difficulty sleeping and are irritable or cry persistently.
Fever can also be an important indicator. When the temperature is high and persists for several days, accompanied by cough, mucus, and difficulty breathing, it's advisable to seek medical advice. Consult your pediatrician or an emergency room immediately.especially if the child is under two years old.
Other warning signs that are described include difficulty feeding (refusal of the breast or bottle), marked lethargy, paleness, or even a bluish or purplish discoloration of the lips and the area around the mouth. In very young infants, these symptoms can appear rapidly and require observation or hospital admission.
Health teams emphasize that, when in doubt, it is best to consult a doctor. During the autumn and winter months—when RSV circulates more intensely—children under two years old, and especially those under six months, They constitute the group with the highest risk of complicationsHence the importance of both maternal vaccination and early attention to symptoms.
Measures to prevent bronchiolitis in babies
Although the RSV vaccine during pregnancy is a key tool, specialists remind us that Bronchiolitis prevention is not based solely on immunizationDaily hygiene and care measures remain essential to reduce the risk of contagion from this and other respiratory viruses.
One of the simplest and most effective guidelines is the frequent hand washing with soap and waterfor at least 20 seconds. When this is not possible, the use of alcohol-based solutions is recommended. This practice should be standard practice for all people who live with or are in close contact with young babies.
It is also suggested Avoid direct contact with people who have respiratory symptomsSymptoms such as cough, runny nose, or fever are common. If possible, those with a cold should avoid kissing the baby on the face or hands and maintain physical distance, especially if the child is under six months old.
Another important measure is the regular ventilation of enclosed spacesOpening windows frequently to refresh the air, even on cold days, is essential. Furthermore, it is crucial to avoid exposure to smoke, including tobacco smoke, both at home and in vehicles or other spaces where the child spends time.
Finally, the importance of complete childhood vaccination schedules, in particular vaccines against pneumococcus, pertussis, the rotavirus vaccine and COVID-19, when recommended according to age and current guidelines. Keeping these immunizations up to date helps reduce the overall impact of respiratory infections in childhood.
The bronchiolitis vaccination campaign based on maternal immunization against RSV is consolidating itself as a key tool to protect the youngest babiesThis has significantly reduced severe forms of the disease and eased pressure on pediatric services during the colder months; however, coverage can still be improved, and that is why authorities insist that pregnant women entering weeks 32 to 36 go to their health center to receive the dose, combining this protection with hygiene measures and early identification of symptoms in newborns.
