Table 2.
Summary of characteristics of clinical trials of coronavirus disease 2019 vaccine and efficacy data
| Vaccine name |
|||||
|---|---|---|---|---|---|
| BNT162b2 [13,27] | mRNA-1273 [14,31] | AZD1222 [15,28,29] | Ad26.COV2.S [16,30] | ||
| Manufacturer | Pfizer | Moderna | AstraZeneca | Janssen (J&J) | |
| Clinical trial (published data) | |||||
| Phase 1/2 | - Phase 1/2 (start: 2020.05) BNT162b1 and BNT162b2 both induced anti-SARSCoV-2 immune responses | - Phase 1/2 (start: 2020.03) mRNA-1273 induced anti-SARS-CoV-2 immune responses in all participants | - Phase 1/2 (start: 2020.04) | - Phase 1/2a (start: 2020.07) | |
| - Neutralizing Ab response: After dose 1 - 91%, dose 2 - 100% | - Single dose seroconversion for S antibodies (by ELISA): Cohort 1a: 99%; cohort 3: 100% | ||||
| - BNT162b2 had less systemic reaction; therefore, was selected for phase 3 clinical trial | - No trial-limiting safety concerns | - No serious adverse events related to ChAdOx1 nCOV-19 | |||
| Phase 3 | Phase 2/3 (start: 2020.07) | Phase 3 (start 2020.07) | Phase 2/3 (start 2020.04) | Phase 3 ENSEMBLE (start 2020.09-): | |
| Country: US, Argentina, Brazil, South Africa, Germany, Turkey | Country: US | Country: UK, Brazil | Country: Argentina, Brazil, Chile, Colombia, Mexico, Peru, South Africa, US | ||
| N=30,420 | N=23,848 | ||||
| N=43,548 | 28-day interval/2-dose | LD/SD (UK): n=2,741; | N=43,783 | ||
| 21-day interval/2-dose | SD/SD (UK): n=4,807; | 1-dose | |||
| SD/SD (Brazil): n=4088; | |||||
| Country: UK (phase 1/2 & phase 3), Brazil (3), South Africa (1/2) | |||||
| N=17,177 | |||||
| SD/SD: n=14,379 | |||||
| LD/SD (UK only): n=2,798 | |||||
| 28-day interval/2-dose | |||||
| Study type | Observer-blinded placebocontrolled | Observer-blinded placebocontrolled | Blinded, randomized, controlled trials | Double-blinded placebo-controlled | |
| Phase 3 trial inclusion | ≥16 yr | ≥18 yr | ≥18 yr | ≥18 yr | |
| >55 yr (42.2%) | ≥65 yr (24.8%) | ≥56 yr (12.2%) | ≥65 yr (19.6%) | ||
| Exclusion | History of COVID-19 | Known history of SARS-CoV-2 infection | Severe and/or uncontrolled underlying disease | Pregnant | |
| Treatment with immunosuppressants | Pregnant | Pregnant | Immunocompromised | ||
| Immunocompromised | Breastfeeding | Breastfeeding | Previously received a COVID-19 vaccine | ||
| Treatment with immunosuppressants | Allergies or history of anaphylaxis or other serious adverse reaction to vaccines | ||||
| Immunocompromised | Acute illness | ||||
| Vaccine efficacy at preventing COVID-19 | ≥7 days after 2nd dose: 95% (95% CI*, 90.3%–97.6%) | ≥14 days after 2nd dose (all symptomatic): 94.1% (95% CI, 89.3%–96.8%) | ≥14 days after 2nd dose (all symptomatic): 70.4% (95% CI: 54.8%–80.6%) | ≥14 days after single dose (all symptomatic): 66.9% (95% CI: 59.1%–73.4%) | |
| Confirmed COVID-19 cases after last vaccination (endpoint) | Vaccine group: n=8/18,198 | Vaccine group: 11/14,134 | Vaccine group: 30/5807 | Vaccine group: 117/19,630 | |
| Placebo group: n=162/18,325 | Placebo group: 185/14,073 | Control groupa): 101/5829 | Placebo group: 351/19,691 | ||
ELISA, enzyme-linked immunosorbent assay; US, United States; UK, United Kingdom; CI, confidence interval; CI*, credible interval; LD, low dose; SD, standard dose.
a)
Control group received meningococcal groups A, C, W, and Y conjugate vaccine or saline.