Immunogenicity and safety of 4 intramuscular standard-dose and high-dose hepatitis B vaccine in people living with HIV: a randomized, parallel-controlled trial.

OBJECTIVES: The immunogenicity of hepatitis B vaccine is unsatisfactory in the people living with HIV (PLHIV). Studies evaluating optimal regimens to enhance immunogenicity have heretofore been inconclusive. The study was to compare the immunogenicity and safety of the four standard-dose and high-dose regimens of hepatitis B vaccine among PLHIV. METHODS: A randomized, parallel-controlled trial was conducted between May, 2020, and January, 2021. Patients were randomly assigned to receive 3 or 4 doses of 20 or 60 µg of hepatitis B vaccine. Seroconversion rate, high-level response rate, and geometric mean concentration (GMC) of antibody to hepatitis B surface antigen (anti-HBs) at weeks 12 and 28 were the main outcome measures. RESULTS: At week 28, the seroconversion rate and GMC of anti-HBs in both IM20 × 4 and IM60 × 4 groups were significantly higher than those in the IM20 × 3 group (P < 0.05), and the GMC of anti-HBs was numerically higher in the IM60 × 4 group than that in the IM20 × 4 group. CONCLUSIONS: In PLHIV, both the four standard-dose and high-dose regimens significantly improved immunogenicity. The GMC of anti-HBs was numerically higher in the IM60 × 4 group than that in the IM20 × 4 group. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT03962803).

Safety and immunogenicity of inactivated SARS-CoV-2 vaccine in high-risk occupational population: a randomized, parallel, controlled clinical trial.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (COVID-19) have a substantial burden on health-care systems around the world. This is a randomized parallel controlled trial for assessment of the immunogenicity and safety of an inactivated SARS-CoV-2 vaccine, aiming to determine an appropriate vaccination interval of the vaccine for high-risk occupational population. METHODS: In an ongoing randomized, parallel, controlled phase IV trial between January and May 2021 in Taiyuan City, Shanxi Province, China, we randomly assigned the airport ground staff and public security officers aged 18 to 59 years to receive two doses of inactivated SARS-CoV-2 vaccine at 14 days, 21 days, or 28 days. The serum neutralizing antibody to live SARS-CoV-2 was performed at baseline and 28 days after immunization. Long-term data are being collected. The primary immunogenicity endpoints were neutralization antibody seroconversion and geometric mean titer (GMT) at 28 days after the second dose. Analysis of variance (ANOVA), chi-square, and logistic regression analysis were used for data analysis. RESULTS: A total of 809 participants underwent randomization and received two doses of injections: 270, 270, 269 in the 0-14, 0-21, and 0-28 vaccination group, respectively. By day 28 after the second injection, SARS-CoV-2 neutralizing antibody of GMT was 98.4 (95% CI: 88.4-108.4) in the 0-14 group, which was significantly lower compared with 134.4 (95% CI: 123.1-145.7) in the 0-21 group (P < 0.001 vs 0-14 group) and 145.5 (95% CI: 131.3-159.6) in the 0-28 group (P < 0.001 vs 0-14 group), resulting in the seroconversion rates to neutralizing antibodies (GMT ≥ 16) of 100.0% for all three groups, respectively. The intention-to-treat (ITT) analysis yielded similar results. All reported adverse reactions were mild. CONCLUSIONS: Both a two-dose of inactivated SARS-CoV-2 vaccine at 0-21 days and 0-28 days regimens significantly improved SARS-CoV-2 neutralizing antibody level compared to the 0-14 days regimen in high-risk occupational population, with seroconversion rates of 100.0%. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2100041705, ChiCTR2100041706. Registered 1 January 2021, www.chictr.org.cn .