Objective: This study aims to evaluate the safety and immunogenicity of the SKYVaricella vaccine in healthy Vietnamese children aged 12 months to 12 years. Methods: This open-label, single-arm study involved 201 children divided into two groups: 60 children aged 12 months to 5 years and 141 children aged 6 to 12 years. Safety was assessed through immediate reactions, solicited adverse events within 7 days, and unsolicited events up to Day 42. Immunogenicity was evaluated by seroconversion rates (SCR) and geometric mean titer (GMT) increments using fluorescent antibody-to-membrane antigen (FAMA) on the day of vaccination (D0) and 42 days after vaccination (D42). Results: All participants completed the follow-up. Immediate adverse events included pain (8.0%), redness (8.0%), and swelling (20.9%) at the injection site. Within 7 days, pain (17.9%) and swelling (12.4%) were mild and self-resolving. Unsolicited adverse events were infrequent and mild. Both age groups achieved 100% SCR. GMT of varicella-zoster virus antibodies increased from 1.37 (SD 1.97) at D0 to 18.02 (SD 2.22) at D42, a 13.12-fold rise. No Grade 3 adverse events were observed. Conclusion: The SKYVaricella vaccine shows a robust immunogenic response and favorable safety profile in Vietnamese children aged 12 months to 12 years. These findings endorse its potential inclusion in pediatric vaccination programs as a reliable preventive option against varicella.

Hung PN, et al. Clin Exp Vaccine Res. 2025 Jan;14(1):51-58. https://doi.org/10.7774/cevr.2025.14.e9

Background: Pneumococcal conjugate vaccines (PCVs) prevent severe disease in children, but high costs limit access. PNEUMOSIL®, a 10-valent PCV prequalified by World Health Organization (WHO) in 2019, offers a cost-effective alternative. This study assessed its safety and immunogenicity in Vietnamese children aged 6 weeks–24 months. Methods: An open-label, single-arm study enrolled 304 children in three age groups: 6 weeks–6 months (n=151), >6–12 months (n=76), and >12–24 months (n=77). Participants received two or three doses. Safety was evaluated through immediate reactions, adverse events (AEs), serious adverse events (SAEs), and withdrawals. Immunogenicity was measured 28 days after the final dose using serotype-specific IgG geometric mean concentrations (GMCs), opsonophagocytic activity (OPA) titers, and seroresponse rates. The trial was approved by the IRB of the National Ethics Council (code: No. 75/CN-HĐĐĐ on date June 4th, 2021) and was registered with ClinicalTrials.gov, NCT05140720. Results: Of 304 enrolled participants, 294 (96.7%) completed follow-up. No immediate adverse events or serious adverse events occurred. Unsolicited adverse events were reported in 17%, mainly respiratory, while serious adverse events occurred in 4%. Mild local/systemic reactions (e.g., injection site pain, crying) resolved without sequelae. Immunogenicity was strong, with GMCs 1.8–9.11 µg/mL, GMTs 277.8–22,342, and >90% achieving seroresponse for all 10 serotypes. Conclusions: PNEUMOSIL® demonstrated favorable safety and robust immunogenicity, supporting its inclusion in national immunization programs as an affordable option for pneumococcal disease prevention.

In this paper, a new reducing agent known as ferro-silicocalcium is being studied for its application in magnesium production through the Pidgeon process. Ferro-silicocalcium with main phase components CaSi2 and Si can reduce Mg from dolomite at a lower temperature than a traditional reducing agent. It thus improves the efficiency of magnesium production and solves the large energy consumption problem of the Pidgeon process. This paper presents thermodynamics calculations and experimental study on reducing magnesium from Thanhhoa dolomite with the new reducing agents known as ferro-silicocalcium and ferrosilicon as traditional reducing agents. From the thermodynamics calculations, CaSi2 in the ferro-silicocalcium can eliminate magnesium oxide at temperatures 1000°C lower than FeSi2 in ferrosilicon. This leads to a substantial decrease in the recovery temperature. When CaSi2 is decomposed, it releases silicon to improve the reduction process at temperatures greater than 1100°C. Experiments are performed to confirm the calculation results. The reduction process of dolomite by ferro-silicocalcium and ferrosilicon was analyzed by phases analysis of reduction slag through X-ray diffraction. The experimental results show that when using ferro-silicocalcium as a reducing agent, the recovering magnesium oxide efficiency reaches 91.3% over three hours with a recovering temperature of 1200°C. The efficiency is 7% higher than the traditional method using ferrosilicon under the same conditions. This proves that using ferro-silicocalcium as a reducing agent reduces the operating temperature of the reducing system and saves energy for the whole process. Therefore, ferro-silicocalium promises to be an effective alternative reducing agent in magnesium production.

Background: Pneumococcal conjugate vaccines (PCVs) prevent severe disease in children, but high costs limit access. PCV10-SII (PNEUMOSIL), a 10-valent PCV prequalified by the World Health Organization (WHO) in 2019, offers a cost-effective alternative. This study assessed its safety and immunogenicity in Vietnamese children aged 6 weeks–24 months. Methods: An open-label, single-arm study enrolled 304 children in three age groups: 6 weeks–6 months (n = 151), >6–12 months (n = 76), and >12–24 months (n = 77). Participants received two or three doses. Safety was evaluated through immediate reactions, adverse events (AEs), serious adverse events (SAEs), and withdrawals. Immunogenicity was measured 28 days after the final dose using serotype-specific IgG geometric mean concentrations (GMCs), opsonophagocytic activity (OPA) titers, and seroresponse rates. The trial was approved by the IRB of the National Ethics Council (code: No. 75/CN-HĐĐĐ on date 4 June 2021) and was registered with ClinicalTrials.gov, NCT05140720. Results: Of 304 enrolled participants, 294 (96.7%) completed follow-up. No immediate adverse events or serious adverse events occurred. Unsolicited adverse events were reported in 17%, mainly respiratory, while serious adverse events occurred in 4%. Mild local/systemic reactions (e.g., injection site pain, crying) resolved without sequelae. Immunogenicity was strong, with GMCs 1.8–9.11 µg/mL, GMTs 277.8–22,342, and seroresponse rates >90% for 9 of 10 serotypes, serotype 6B demonstrated a slightly lower seroresponse rate of 88.6%. Conclusions: PCV10-SII demonstrated favorable safety and robust immunogenicity, supporting its inclusion in national immunization programs as an affordable option for pneumococcal disease prevention.