Tin tức
Tin tức
Phòng ngừa rsv ở trẻ
Phòng ngừa rsv ở trẻ . Tuy nhiên Việt Nam và đặc biệt miền nam không có mùa rõ rệt mà xuất hiện rải rác quanh năm.
IMMUNOPROPHYLAXIS
Monoclonal antibodies
●Nirsevimab – Nirsevimab is a monoclonal antibody that targets the prefusion conformation of the RSV F glycoprotein. It has a long half-life and potent neutralizing activity. A dose of nirsevimab is expected to provide protection for at least five months such that only one dose is needed at the beginning of the RSV season. Nirsevimab was approved by the US Food and Drug Administration (FDA) in 2023 [15,16].
•Efficacy – In multicenter, placebo-controlled trials in otherwise healthy infants born at ≥29 weeks' gestation entering their first RSV season, a single injection of nirsevimab appeared to be safe and effective in preventing RSV lower respiratory tract infection (LRTI) that required medical attention (eg, emergency department or clinic visit) and RSV-associated hospitalization [17-19]. In one study, more than 1400 infants born between 29 and 35 weeks' gestation were randomly assigned in a 2:1 ratio to receive a dose of nirsevimab or placebo [17], and in another study, more than 1400 infants who were born ≥35 weeks' gestation were randomly assigned in the same manner [18].
In the first study, infants assigned to receive nirsevimab had fewer RSV LRTIs requiring medical attention than those receiving placebo (2.6 versus 9.5 percent, relative efficacy 70.1 percent, 95% CI 52.3- to 81.2), and the incidence of hospitalization at five months was lower (0.8 versus 4.1 percent, relative efficacy 78.4 percent, 95% CI 51.9 to 90.3) [17]. Similarly, in the second study, fewer infants receiving nirsevimab required medical attention (1.2 versus 5.0 percent, relative efficacy 74.5 percent, 95% CI 49.6 to 87.1), and they had a lower incidence of hospitalization (0.6 versus 1.6 percent, relative efficacy 62.1 percent, 95% CI -8.6 to 86. [18].
In another study conducted in France, Germany, and the United Kingdom, more than 8000 otherwise healthy infants ≤12 months, born at ≥29 weeks' gestation, and entering their first RSV season were assigned to receive one dose of nirsevimab or no intervention [20]. The group who received nirsevimab had fewer hospitalizations for RSV-associated LRTI (0.3 versus 1.5 percent, efficacy 83.2 percent, 95% CI 67.8-92.0) and fewer infants with an oxygen saturation <90 percent (0.1 versus 0.5 percent, efficacy 75.7 percent, 95% CI 32.8-92.9).
•Effectiveness – A meta-analysis was conducted to evaluate the effectiveness of nirsevimab for the prevention of RSV-related hospitalizations, intensive care unit (ICU) admissions, and LRTI in infants 0 to 12 months of age across five countries [21]. Receipt of nirsevimab was associated with fewer events for all three outcomes compared with no receipt of nirsevimab: RSV-related hospitalizations (1.9 versus 7.7 percent; odds ratio [OR] 0.17, 95% CI 0.12-0.23; 16 studies, 137,135 infants); ICU admissions (0.2 versus 1.3 percent; OR 0.19, 95% CI 0.12-0.29; nine studies, 127,568 infants); and LRTIs (0.8 versus 11 percent; OR 0.25, 95% CI 0.19-0.33; seven studies, 57,872 infants).
Surveillance data from the New Vaccine Surveillance Network (NVSN) and the Respiratory Syncytial Virus-Associated Hospitalization Surveillance Network (RSV-NET) demonstrated a substantial reduction in RSV-associated infant hospitalizations in the general population, regardless of treatment, between the 2018 to 2020 seasons and the 2024 to 2025 RSV season. The 2024 to 2025 RSV season was the first season in which RSV immunologic agents were widely available for infants (nirsevimab for infants during their first RSV season or RSV vaccine during pregnancy) [22]. The reduction was most pronounced for infants 0 to 2 months of age (RSV-NET: 22.2 versus 10.6 per 1000 infants, relative rate reduction [RRR] 52 percent, 95% CI 49-56 percent; NVSN: 21.7 versus 12 per 1000 infants, RRR 45 percent, 95% CI 32-57 percent) but was seen in infants up to seven months of age.
●Clesrovimab – Clesrovimab is another RSV monoclonal antibody that was FDA-approved in 2025 [23]. As with nirsevimab, clesrovimab targets the prefusion conformation of the RSV F glycoprotein but at a different antigenic site and is expected to provide protection for at least five months. Unlike nirsevimab, clesrovimab is only approved for use in infants ≤12 months of age.
The efficacy and safety of clesrovimab were evaluated in two trials [23]. The first was a placebo-controlled trial conducted in neonates and infants ≥35 weeks' gestation from 22 countries. The incidence rate of hospitalization was lower in the clesrovimab group than the placebo group (0.4 versus 2.4 percent; efficacy 84 percent [95% CI 66.7-92.6 percent]). The second trial was a palivizumab-controlled trial that enrolled preterm infants (≤35 weeks gestational age) and infants of any gestational age that were at increased risk for severe disease. The incidence rate of hospitalization was similar in the clesrovimab and palivizumab groups (1.3 versus 1.5 percent; overlapping confidence intervals).
Effectiveness trials have not been conducted as of the time that clesrovimab became commercially available.
We agree with the recommendations of the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) for administering nirsevimab or clesrovimab, and these are reflected in the following sections (table 1) [15,24-27].
First RSV season
Infants <8 months
Birthing parent did not receive RSV vaccination during pregnancy — We recommend that all infants younger than eight months who are born during the RSV season or are entering their first RSV season receive one dose of an RSV monoclonal antibody (ie, nirsevimab or clesrovimab) if the birthing parent did not receive RSV vaccination during pregnancy or the vaccination status of the birthing parent is unknown. Details regarding the dose and administration of nirsevimab and clesrovimab are presented below. (See 'Administration' below.)
If nirsevimab or clesrovimab are not received on time, one of them should be administered at any time during the RSV season unless the infant has reached eight months of age.
Birthing parent did receive RSV vaccine during pregnancy
●Vaccination occurred <14 days before delivery – We recommend that all infants who are born during the RSV season or are entering their first RSV season receive one dose of an RSV monoclonal antibody if their birthing parent was vaccinated within 14 days of delivery.
●Vaccination occurred ≥14 days before delivery – We do not recommend immunoprophylaxis for infants whose birthing parent was vaccinated more than 14 days before delivery.
However, if any of the following exceptions apply, an RSV monoclonal antibody may be given if the provider judges that the incremental benefit to the infant is warranted: the birthing parent has a condition that may prevent an adequate immune response or is associated with reduced transplacental antibody transfer (eg, persons with immunocompromising conditions); the infant requires cardiopulmonary bypass or extracorporeal membrane oxygenation; or the infant is at substantial increased risk for severe RSV disease (eg, hemodynamically significant heart disease, intensive care admission, oxygen requirement at discharge).
Details regarding the timing and dose of nirsevimab and clesrovimab are presented below. (See 'Administration' below.)
Infants ≥8 months
●Healthy infants ≥8 months old who did not receive a dose of an RSV monoclonal antibody on time are not eligible for a catch-up dose.
●Infants at increased risk for severe disease who did not receive an RSV monoclonal antibody before eight months of age should receive one dose of an RSV monoclonal antibody. Criteria for increased risk are listed in the table (table 1). Details regarding the timing and dose of RSV monoclonal antibodies are presented below. (See 'Administration' below.)
Second RSV season
All infants <8 months — All infants who did not receive an RSV monoclonal antibody during their first RSV season and are younger than eight months entering their second RSV season should receive a dose of nirsevimab or clesrovimab. On the other hand, healthy infants who received an RSV monoclonal antibody during their first RSV season should not receive another dose, even if they are less than eight months of age.
Details regarding the timing and dose of RSV monoclonal antibodies are presented below. (See 'Administration' below.)
Infants 8 through 19 months at increased risk for severe disease — We suggest that infants and children who are 8 through 19 months old and at increased risk for severe RSV receive a second dose of nirsevimab upon entry into their second RSV season (table 1). This advice also applies to infants who received palivizumab or clesrovimab during their first RSV season. Clesrovimab is not approved for this indication.
Criteria for increased risk of severe disease include [15]:
●Children with bronchopulmonary dysplasia (BPD; also known as chronic lung disease of prematurity) who required medical support (eg, chronic corticosteroid therapy, diuretic therapy, or supplemental oxygen) any time during the six-month period before the start of the RSV season
●Children who are severely immunocompromised
●Children with cystic fibrosis who have manifestations of severe lung disease (previous hospitalization for pulmonary exacerbation in the first year of life or abnormalities on chest imaging that persist when stable) or have weight-for-length <10th percentile
●American Indian and Alaska Native children
For the purpose of RSV monoclonal antibody prophylaxis, we use the definition for BPD provided in the AAP guidelines: gestational age <32 weeks and a requirement for supplemental oxygen for the first 28 days after birth [28]. (See "Bronchopulmonary dysplasia (BPD): Clinical features and diagnosis", section on 'Definitions and severity of BPD'.)
Details regarding the timing and dose of nirsevimab are presented below. (See 'Administration' below.)
Administration
Timing — RSV season in most of the continental United States generally runs from October to the end of March. Because this varies geographically, health care providers should adjust the timing of immunoprophylaxis if indicated by their community's RSV activity.
●Infants born during RSV season – Nirsevimab or clesrovimab should be administered within the first week of life. If the infant's hospitalization after birth is extended due to prematurity or other problems, the monoclonal antibody should be administered shortly before or promptly after hospital discharge.
●Infants born before RSV season – Nirsevimab or clesrovimab should be administered shortly before the season begins. Eligible infants who do not receive the monoclonal antibody before the RSV season begins may receive it at any time before the season ends. For healthy infants, eligibility requires that they be <8 months old at the time of administration.
●Children with increased risk for severe disease entering their second RSV season – All children ≤19 months with increased risk should receive a second dose of nirsevimab just before the start of the RSV season. This includes infants who received palivizumab or clesrovimab during their first RSV season. (See 'Infants 8 through 19 months at increased risk for severe disease' above.)
Dose
●Nirsevimab – The dose of nirsevimab is based on weight and age.
•Infant's first RSV season
-Weight <5 kg – One 50 mg intramuscular (IM) dose
-Weight ≥5 kg – One 100 mg IM dose
•Child's second RSV season
-One 200 mg IM dose
●Clesrovimab – Clesrovimab is only licensed to be used in infants <12 months of age. One 105 mg IM dose is administered regardless of the infant's weight.
When age-appropriate vaccines are indicated, simultaneous administration of an RSV monoclonal antibody is recommended.
Adverse events — Adverse events reported in the two multicenter trials of healthy infants ≥29 weeks gestation were similar between the nirsevimab groups and the placebo groups, including serious adverse events [17,18]. Additionally, there were no anaphylactic reactions. Five deaths (0.3 percent) occurred in the nirsevimab groups and three (0.3 percent) occurred in the placebo groups. None of the deaths were judged by the investigators to be related to nirsevimab or placebo. Postmarketing, serious hypersensitivity reactions have been reported in infants and young children receiving nirsevimab [29]. These include urticaria, dyspnea, cyanosis, and hypotonia.
Adverse events were assessed in two trials; they were similar between the clesrovimab group and placebo group in one trial and between the clesrovimab group and palivizumab group in the other trial [23]. There are no postmarketing data for clesrovimab yet.