Immunogenicity and safety of SARS-CoV-2 recombinant protein subunit vaccine (IndoVac) adjuvanted with alum and CpG 1018 in Indonesian adults: A phase 3, randomized, active-controlled, multicenter trial.

BACKGROUND: Bio Farma has developed a recombinant protein subunit vaccine (IndoVac) that is indicated for active immunization in population of all ages. This article reported the results of the phase 3 immunogenicity and safety study in Indonesian adults aged 18 years and above. METHODS: We conducted a randomized, active-controlled, multicenter, prospective intervention study to evaluate the immunogenicity and safety of IndoVac in adults aged 18 years and above. Participants who were SARS-CoV-2 vaccine-naïve received two doses of either IndoVac or control (Covovax) with 28 days interval between doses and were followed up until 12 months after complete vaccination. RESULTS: A total of 4050 participants were enrolled from June to August 2022 and received at least one dose of vaccine. The geometric mean ratio (GMR) of neutralizing antibody at 14 days after the second dose was 1.01 (95 % confidence interval (CI) 0.89-1.16), which met the WHO non-inferiority criteria for immunobridging (95 % CI lower bound > 0.67). The antibody levels were maintained through 12 months after the second dose. The incidence rate of adverse events (AEs) were 27.95 % in IndoVac group and 32.15 % in Covovax group with mostly mild intensity (27.70 %). The most reported solicited AEs were pain (14.69 %) followed by myalgia (7.48 %) and fatigue (6.77 %). Unsolicited AEs varied, with each of the incidence rate under 5 %. There were no serious AEs assessed as possibly, probably, or likely related to vaccine. CONCLUSIONS: IndoVac in adults showed favourable safety profile and elicited non-inferior immune response to Covovax. (ClinicalTrials.gov: NCT05433285, Indonesian Clinical Research Registry: INA-R5752S9).

Characteristics, attitudes, and the odds for positive attitude toward clinical trial: A study on Indonesian COVID-19 vaccine trial participants.

Aims: This study was performed to understand the Indonesian population's characteristics and the factors that contribute to a more positive attitude toward participation in a clinical trial. Methods: A cross-sectional survey was conducted involving 402 COVID-19 vaccine trial participants in Semarang, Indonesia, utilizing self-reporting questionnaires consisting of questions related to socio-demographic characteristics and statements in a 5-scaled Likert Scale to assess the attitude toward vaccine trial. The odds for positive attitude were analyzed using Ordinal Logistic Regression to obtain the odd-ratio and 95% confidence interval. The P < 0.05 was considered statistically significant. Results: Most of the respondents were adults aged 22-64-year-old (89.30%), males (63.68%), married (77.61%), worked as an employee (59.70%), obtained information about the clinical trial from the Public Health Service (41.29%), had a low education level (40.80%), a low monthly income level (68.41%), with no previous participation in a clinical trial (90.80%). All respondents showed a good attitude toward the trial, with low education level, nonemployment status, fewer or no previous participation in clinical trials, and getting the information from the public health centers were the main predictors for better attitude toward vaccine trials. Conclusion: There was a positive attitude toward vaccine trials in the Indonesian population. The positive attitude could be driven by having a low education level, nonemployment status, fewer or no previous participation in the clinical trial, and getting information from public health centers.

Protectivity and safety following recombinant hepatitis B vaccine with different source of bulk compared to hepatitis B (Bio Farma) vaccine in Indonesia.

PURPOSE: Indonesia, a high populous and the second-highest country in epidemicity of hepatitis B in South-East Asia require maintaining its capacity of monovalent hepatitis B production to keep up with both the national immunization program and global needs. To keep the sustainability of the vaccine, a new bulk is needed to be made available. This study aims to evaluate the immunogenicity and safety of Bio Farma newly formulated recombinant hepatitis B vaccines, which came from different sources of bulk, compared to the already registered hepatitis B vaccine. MATERIALS AND METHODS: An experimental, randomized, double-blind, cohort intervention phase II clinical trial was conducted on three recombinant hepatitis B vaccines from different bulk sources, with Bio Farma registered hepatitis B vaccine as the control group. A total of 536 participants around age 10 to 40 years old were thricely vaccinated with twice serological assessments. The subject's safety was monitored for 28 days after each vaccination. RESULTS: Of 536 enrolled participants, 521 finished the vaccination and serology assessments. The investigational products were proven not to be inferior to the control. All vaccines were well tolerated. No differences in rates of local and systemic reactions were seen between the investigational products and control. No serious adverse event was found to be related to the investigational vaccines. CONCLUSION: Investigational vaccines are shown to be equally immunogenic and safe as the control vaccine.

Desialylation of platelets induced by Von Willebrand Factor is a novel mechanism of platelet clearance in dengue.

Thrombocytopenia and platelet dysfunction are commonly observed in patients with dengue virus (DENV) infection and may contribute to complications such as bleeding and plasma leakage. The etiology of dengue-associated thrombocytopenia is multifactorial and includes increased platelet clearance. The binding of the coagulation protein von Willebrand factor (VWF) to the platelet membrane and removal of sialic acid (desialylation) are two well-known mechanisms of platelet clearance, but whether these conditions also contribute to thrombocytopenia in dengue infection is unknown. In two observational cohort studies in Bandung and Jepara, Indonesia, we show that adult patients with dengue not only had higher plasma concentrations of plasma VWF antigen and active VWF, but that circulating platelets had also bound more VWF to their membrane. The amount of platelet-VWF binding correlated well with platelet count. Furthermore, sialic acid levels in dengue patients were significantly reduced as assessed by the binding of Sambucus nigra lectin (SNA) and Maackia amurensis lectin II (MAL-II) to platelets. Sialic acid on the platelet membrane is neuraminidase-labile, but dengue virus has no known neuraminidase activity. Indeed, no detectable activity of neuraminidase was present in plasma of dengue patients and no desialylation was found of plasma transferrin. Platelet sialylation was also not altered by in vitro exposure of platelets to DENV nonstructural protein 1 or cultured DENV. In contrast, induction of binding of VWF to glycoprotein 1b on platelets using the VWF-activating protein ristocetin resulted in the removal of platelet sialic acid by translocation of platelet neuraminidase to the platelet surface. The neuraminidase inhibitor oseltamivir reduced VWF-induced platelet desialylation. Our data demonstrate that excessive binding of VWF to platelets in dengue results in neuraminidase-mediated platelet desialylation and platelet clearance. Oseltamivir might be a novel treatment option for severe thrombocytopenia in dengue infection.