A Meta-Analysis on the Safety and Immunogenicity of Covid-19 Vaccines.

OBJECTIVE: The presented meta-analysis (MA) aims at identifying the vaccine safety and immunogenicity in published trials about SARS-CoV-2 vaccines. METHODS: All relevant publications were systematically searched and collected from different databases (Embase, Scopus, EBSCO, MEDLINE central/PubMed, Science Direct, Cochrane Central Register for Clinical Trials (CENTRAL), Clinical Trials.gov, WHO International Clinical Trials Registry Platform (ICTRP), COVID Trial, COVID Inato, Web of Science, ProQuest Thesis, ProQuest Coronavirus Database, SAGE Thesis, Google Scholar, Research Square, and Medxriv) up to January 10, 2021. The pooled vaccine safety and immunogenicity following vaccination in phase 1 and 2 vaccine clinical trials, as well as their 95% confidence intervals (CI), were estimated using the random-effects model. RESULTS: The predefined inclusion criteria were met in 22 out of 8592 articles. The proportion of anti-severe acute respiratory distress coronavirus 2 (SARS-CoV-2) antibody responses after 7 days among 72 vaccinated persons included in 1 study was 81% (95% CI: 70-89), after 14 days among 888 vaccinated persons included in 6 studies was 80% (95% CI: 58-92), after 28 days among 1589 vaccinated persons included in 6 studies was 63% (95% CI: 59-67), after 42 days among 478 vaccinated persons included in 5 studies was 93% (95% CI: 80-98), and after 56 days among 432 vaccinated persons included in 2 studies was 93% (95% CI: 83-97). Meta regression explains more than 80% of this heterogeneity, where the main predictors were; the inactivated vaccine type (ß = 2.027, P = 0.0007), measurement of antibodies at week 1 (ß = -4.327, P < 0.0001) and at week 3 of the first dose (ß = -2.02, P = 0.0025). Furthermore, the pooled proportion adverse effects 7 days after vaccination was 0.01 (0.08-0.14) for fever, headache 0.23 (0.19-0.27), fatigue 0.10 (0.07-0.13), and 0.18 (0.14-0.23) for muscle pain. CONCLUSION: Immunogenicity following vaccination ranged from 63% to 93% depending on the time at which the antibody levels were measured.

COVID-19 Vaccine Booster Dose Acceptance: Systematic Review and Meta-Analysis.

The World Health Organization (WHO) recommended coronavirus disease 2019 (COVID-19) booster dose vaccination after completing the primary vaccination series for individuals ≥18 years and most-at-risk populations. This study aimed to estimate the pooled proportion of COVID-19 vaccine booster dose uptake and intention to get the booster dose among general populations and healthcare workers (HCWs). We searched PsycINFO, Scopus, EBSCO, MEDLINE Central/PubMed, ProQuest, SciELO, SAGE, Web of Science, Google Scholar, and ScienceDirect according to PRISMA guidelines. From a total of 1079 screened records, 50 studies were extracted. Meta-analysis was conducted using 48 high-quality studies according to the Newcastle-Ottawa Scale quality assessment tool. Using the 48 included studies, the pooled proportion of COVID-19 vaccine booster dose acceptance among 198,831 subjects was 81% (95% confidence interval (CI): 75-85%, I2 = 100%). The actual uptake of the booster dose in eight studies involving 12,995 subjects was 31% (95% CI: 19-46%, I2 = 100%), while the intention to have the booster dose of the vaccine was 79% (95% CI: 72-85%, I2 = 100%). The acceptance of the booster dose of COVID-19 vaccines among HCWs was 66% (95% CI: 58-74%), I2 = 99%). Meta-regression revealed that previous COVID-19 infection was associated with a lower intention to have the booster dose. Conversely, previous COVID-19 infection was associated with a significantly higher level of booster dose actual uptake. The pooled booster dose acceptance in the WHO region of the Americas, which did not include any actual vaccination, was 77% (95% CI: 66-85%, I2 = 100%). The pooled acceptance of the booster dose in the Western Pacific was 89% (95% CI: 84-92%, I2 = 100), followed by the European region: 86% (95% CI: 81-90%, I2 = 99%), the Eastern Mediterranean region: 59% (95% CI: 46-71%, I2 = 99%), and the Southeast Asian region: 52% (95% CI: 43-61%, I2 = 95). Having chronic disease and trust in the vaccine effectiveness were the significant predictors of booster dose COVID-19 vaccine acceptance. The global acceptance rate of COVID-19 booster vaccine is high, but the rates vary by region. To achieve herd immunity for the disease, a high level of vaccination acceptance is required. Intensive vaccination campaigns and programs are still needed around the world to raise public awareness regarding the importance of accepting COVID-19 vaccines needed for proper control of the pandemic.