Debate regarding vaccinating high-risk infants with penta- and hexavalent vaccines persists, despite their good immunogenicity and acceptable safety profile in healthy full-term infants. We report the findings of a systematic literature search that aimed to present data on the immunogenicity, efficacy, effectiveness, safety, impact, compliance and completion of penta- and hexavalent vaccination in high-risk infants, including premature newborns. Data from the 14 studies included in the review showed that the immunogenicity and the safety profile of penta- and hexavalent vaccines in preterm infants was generally similar to those seen in full-term infants, with the exception of an increase in cardiorespiratory adverse events such as apnea, bradycardia and desaturation following vaccination in preterm infants. Despite recommendations of vaccinating preterm infants according to their actual age, and the relatively high completion rate of the primary immunization schedule, vaccination was often delayed, increasing the vulnerability of this high-risk population to vaccine-preventable diseases. Combined vaccines such as penta- and hexavalent vaccines against multiple childhood diseases are widely used in healthy babies born at term. However, it is still debated whether these vaccines act the same way in babies considered to be high-risk: babies born prematurely at <34 weeks of pregnancy, those with a birthweight of <1500 g or babies with chronic diseases. We did a systematic literature search to find studies on such high-risk babies vaccinated with penta- or hexavalent vaccines; we focused on their antibody levels following vaccination, side effects, and protection from the diseases against which they were vaccinated. We also analyzed whether they were vaccinated on time and with all the doses recommended for healthy full-term babies. We found 14 studies that included premature babies. The results of these studies suggest that premature babies’ immune systems respond to penta- and hexavalent vaccines in largely the same way as those of full-term babies; side effects of penta- and hexavalent vaccines are also mostly similar to those seen in full-term babies. However, side effects like pauses in breathing, slow heart rate or low blood oxygen levels seem to be more common in preterm babies; for safety, these babies should be monitored closely after vaccination. Preterm babies are often vaccinated with a delay compared to the recommended schedule. No studies reported data on protection from the diseases covered by penta- and hexavalent vaccinations in preterm babies. More research is needed on penta- and hexavalent vaccination of other high-risk babies besides those born prematurely.

To find out risk factors for disease severity and mortality of pediatric COVID-19 in the fourth wave of COVID-19 in Vietnam. This retrospective cohort study was performed at Children's Hospital 1 from July to December 2021. All children with COVID-19 confirmed by a positive Realtime RT-PCR SARS-CoV-2 result and treated at COVID-19 department for at least 72 h were included. Of the 850 cases admitting to COVID-19 department, 555 children with COVID-19 confirmed by positive RT-PCR and treated at our center for more than 72 h. Median age of confirmed cases was 22.3 (IQR: 3.2–88.6) months, 55.1% were male, and 84.5% had a history of close contact with confirmed COVID-19 patients. The rate of mild, moderate and severe/critical cases was 73,7%, 9.0% and 17.3%, respectively. One hundred ninety-two children (34.6%) had underlying diseases, in which, neurologic disease was the most common underlying disease (7.9%). Underlying disease, dyspnea, elevated CRP >20 mg/L and elevated ferritin were independent factors related to severe illness. Twenty-point two percent of patients in our study needed respiratory support, including 22 invasive mechanical ventilation cases. Eighteen cases (3.2%) died because of severe comorbidities, poor response to treatment. In our study, the severe/critical and mortality rates in pediatric COVID-19 cases were relatively high. All fatal cases had severe comorbidities. Underlying disease, dyspnea, and elevated inflammatory markers were independent factors related to severity in pediatric COVID-19 cases.

Background: Primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri is a rare and devastating infection of the central nervous system, often diagnosed late, due to its rapid progression and nonspecific symptoms. Case Presentation: We report one of the youngest documented pediatric Vietnamese cases of PAM in a 10-month-old girl from the Mekong Delta, Vietnam. The diagnosis was confirmed through multiplex real-time PCR (MPL-rPCR), microscopy, and sequencing. Clinical data were gathered retrospectively from medical records, and additional details were provided by the patient’s family. Treatment regimens, disease progression, and diagnostic challenges were reviewed and compared to existing literature. With intensive treatment, the child survived for 14 days, representing one of the longest reported pediatric PAM survival durations. No direct exposure to untreated freshwater or other typical risk factors for Naegleria fowleri infection was identified, underscoring the unique epidemiological nature of this case. MPL-rPCR enabled timely detection of the pathogen and demonstrated its utility in resource-limited settings. Conclusions: This case highlights the critical need for rapid, accessible diagnostic tools such as MPL-rPCR, particularly in resource-constrained environments where traditional diagnostics may not be feasible. It also emphasizes the importance of international collaboration and investment in cost-effective diagnostics and novel therapeutic strategies. The geographical expansion of PAM due to climate change further underscores the urgency of these measures to improve health outcomes in vulnerable populations.

This study aimed to describe the cardiovascular injury and clinical features of multisystem inflammatory syndrome in children (MIS-C) related to coronavirus disease 2019 (COVID-19) in Ho Chi Minh City, Vietnam. This was a retrospective cohort study of children with MIS-C (from September 1, 2021 to February 28, 2022) in Children's Hospital 1, Ho Chi Minh City. Demographics, clinical history, significant underlying conditions, clinical manifestations, laboratory investigations, and medical management were analyzed. A total of 76 patients were included (median age, 5.9 years old, 2 months–16 years). The male/female ratio was 1.6/1. Most patients (75/76) had no previous medical conditions. The mean time from acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection to symptom onset was 39 days. During an acute SARS-CoV-2 infection, these patients are either asymptomatic or mildly symptomatic. In addition to fever, gastrointestinal symptoms were also prominent, as observed in our study, with 75%, 73.7%, and 72.3% of patients presenting with abdominal pain, vomiting, and loose stools, respectively. The levels of inflammatory markers increased upon admission and returned to normal levels after treatment. Echocardiography revealed decreased myocardial contractility and coronary injury in 16 (21.1%) and 32 (42.1%) patients, respectively. Most cases (72/76) had no fever within 3 days of intravenous immunoglobulin (IVIG) and methylprednisolone treatment. No deaths occurred in this study. The mean duration of hospitalization was 7.2 days. Cardiovascular involvement was observed in approximately 53.9% of the patients. Anti-inflammatory treatment with IVIG and methylprednisolone had a favorable short-term outcome. However, long-term follow-up studies on post-discharge MIS-C cases are needed to make appropriate treatment recommendations in the acute phase.

Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, is life-threatening with a high case fatality rate (CFR) and severe sequelae. We compiled and critically discussed the evidence on IMD epidemiology, antibiotic resistance and disease management in Vietnam, focusing on children. PubMed, Embase and gray literature searches for English, Vietnamese and French publications, with no date restrictions, retrieved 11 eligible studies. IMD incidence rate (/100,000 population) was 7.4 [95% confidence interval 3.6–15.3] in children under 5 years of age; driven by high rates in infants (e.g. 29.1 [8.0–106.0] in 7–11 month-olds). Serogroup B IMD was predominant. Neisseria meningitidis strains may have developed resistance to streptomycin, sulfonamides, ciprofloxacin, and possibly ceftriaxone. There was a lack of current data on diagnosis and treatment of IMD, which remain challenging. Healthcare professionals should be trained to rapidly recognize and treat IMD. Preventive measures, such as routine vaccination, could help address the medical need.

An advisory board meeting was held with experts in Vietnam (Hanoi, August 2022), to review the evidence on invasive meningococcal disease (IMD) epidemiology, clinical management, and meningococcal vaccines to reach a consensus on recommendations for meningococcal vaccination in Vietnam. IMD is a severe disease, with the highest burden in infants and children. IMD presents as meningitis and/or meningococcemia and can progress extremely rapidly. Almost 90% of deaths in children occur within the first 24 h, and disabling sequelae (e.g., limb amputations and neurological damage) occur in up to 20% of survivors. IMD patients are often hospitalized late, due to mild and nonspecific early symptoms and misdiagnosis. Difficulties related to diagnosis and antibiotic misuse mean that the number of reported IMD cases in Vietnam is likely to be underestimated. Serogroup B IMD is predominant in many regions of the world, including Vietnam, where 82% of IMD cases were due to serogroup B (surveillance data from 2012 to 2021). Four component meningococcal B vaccine (4CMenB) is used in many countries (and is part of the pediatric National Immunization Program in 13 countries), with infant vaccination starting from two months of age, and a 2 + 1 dosing schedule. Experts recommend 4CMenB vaccination as soon as possible in Vietnam, starting from two months of age, with a 2 + 1 dosing schedule, and at least completing one dose before 6 months of age.