This study evaluated safety, reactogenicity, and immunogenicity of a 2-month homologous booster regimen of Ad26.COV2.S in Japanese adults.
In this multicenter, placebo-controlled, Phase 1 trial, adults (Cohort 1, aged 20-55 years, N = 125; Cohort 2, aged ≥ 65 years, N = 125) were randomized 2:2:1 to receive Ad26.COV2.S 5 × 1010 viral particles (vp), Ad26.COV2.S 1 × 1011 vp, or placebo, followed by a homologous booster 56 days later. Safety, reactogenicity, and immunogenicity were assessed.
Two hundred participants received Ad26.COV2.S and 50 received placebo. The most frequent solicited local adverse event (AE) was vaccination-site pain, and the most frequent solicited systemic AEs were fatigue, myalgia, and headache. After primary vaccination, neutralizing and binding antibody levels increased through Day 57 (post-prime) in both cohorts. Fourteen days after boosting (Day 71), neutralizing antibody geometric mean titers (GMTs) had almost reached their peak value in Cohort 1 (5 × 1010 vp: GMT = 1049; 1 × 1011 vp: GMT = 1470) and peaked in Cohort 2 (504; 651); at Day 85, GMTs had declined minimally in Cohort 2. For both cohorts, binding antibody levels peaked at Day 71 with minimal decline at Day 85.
A single dose and homologous Ad26.COV2.S booster increased antibody responses with an acceptable safety profile in Japanese adults (ClinicalTrials.gov Identifier: NCT04509947).

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a threat to the health of the global population. As the result of a global effort in the determination of origin, structure, and pathogenesis of SARS-CoV-2 and its variants, particularly such the variant of concern as Delta Variant and Omicron Variant, the understanding of SARS-CoV-2 are deepening and the development of vaccines against SARS-CoV-2 are ongoing. Currently, AstraZeneca-Vaxzevria/SII-Covishield vaccine, Janssen-Ad26.COV2.S vaccine, Moderna-mRNA-1273 vaccine, Pfizer BioNTech-Comirnaty vaccine and Sinovac-CoronaVac vaccine have been listed as WHO Emergency Use Listing (EUL) Qualified Vaccines by WHO. Because of the antigen escape caused by the mutation in variants, the effectiveness of vaccines, which are currently the main means of prevention and treatment, has been affected by varying degrees. Herein, we review the current status of mutations of SARS-CoV-2 variants, the different approaches used in the development of COVID-19 vaccines, and COVID-19 vaccine effectiveness against SARS-CoV-2 variants.

It was urgent and necessary to synthesize the evidence for vaccine effectiveness (VE) against SARS-CoV-2 variants of concern (VOC). We conducted a systematic review and meta-analysis to provide a comprehensive overview of the effectiveness profile of COVID-19 vaccines against VOC.
Published randomized controlled trials (RCTs), cohort studies, and case-control studies that evaluated the VE against VOC (Alpha, Beta, Gamma, Delta, or Omicron) were searched until 4 March 2022. Pooled estimates and 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. VE was defined as (1-estimate).
Eleven RCTs (161,388 participants), 20 cohort studies (52,782,321 participants), and 26 case-control studies (2,584,732 cases) were included. Eleven COVID-19 vaccines (mRNA-1273, BNT162b2, ChAdOx1, Ad26.COV2.S, NVX-CoV2373, BBV152, CoronaVac, BBIBP-CorV, SCB-2019, CVnCoV, and HB02) were included in this analysis. Full vaccination was effective against Alpha, Beta, Gamma, Delta, and Omicron variants, with VE of 88.0% (95% CI, 83.0-91.5), 73.0% (95% CI, 64.3-79.5), 63.0% (95% CI, 47.9-73.7), 77.8% (95% CI, 72.7-82.0), and 55.9% (95% CI, 40.9-67.0), respectively. Booster vaccination was more effective against Delta and Omicron variants, with VE of 95.5% (95% CI, 94.2-96.5) and 80.8% (95% CI, 58.6-91.1), respectively. mRNA vaccines (mRNA-1273/BNT162b2) seemed to have higher VE against VOC over others; significant interactions (pinteraction < 0.10) were observed between VE and vaccine type (mRNA vaccines vs. not mRNA vaccines).
Full vaccination of COVID-19 vaccines is highly effective against Alpha variant, and moderate effective against Beta, Gamma, and Delta variants. Booster vaccination is more effective against Delta and Omicron variants. mRNA vaccines seem to have higher VE against Alpha, Beta, Gamma, and Delta variants over others.

暂无摘要。

Uremia affects all parts of the immune system. Since hemodialysis patients travel to the dialysis center three times per week and are surrounded by many other patients and staffs, these could predispose them to a greater risk of coronavirus disease of 2019 (COVID-19) infection. Mortality associated with COVID-19 infection is high in patients receiving dialysis. Currently, the World Health Organization has approved six types of vaccines (ChAdOx1-S, Ad26.COV2.S, BNT162b2, mRNA-1273, BBIBP-CorV and CoronaVac) for COVID-19. Literature data regarding the response rate toward COVID-19 vaccination in dialysis patients is inconclusive. The published response rates varied from 29.6% to 96.4%. The variable response rates across these clinical trials may be explained by different vaccine types, vaccine doses, criteria for positive immune response, timings of antibody detection, races and ethnicities. Side effects of COVID-19 vaccination comprise of pain at injection site, fatigue, myalgia, headache, low fever, syncope, pericarditis, etc. Clinical predictors of positive response toward COVID-19 vaccination include age, previous infection, immunosuppressive therapy, body mass index and serum albumin level. No one is safe until everyone is safe. Therefore, vaccination against COVID-19 infection in dialysis patients is an urgent issue of worldwide concern.