Table 2.
Current progress in vaccine development
| Strategy | Developer | Protective effect | Cross-protection effect |
|---|---|---|---|
| Inactivated virus (PiCoVacc) | Sinovac, with National Institute for Communicable Disease Control and Prevention | a protective effect of 67% in Chile (real-world data) | slightly reduced effectiveness against B.1.1.7 spike-expressing recombinant virus and 3.3-fold reduction against B.1.351 spike-expressing recombinant virus (in vitro) |
| Inactivated virus | Wuhan Institute of Biological Products, Sinopharm, with Wuhan Institute of Virology, Chinese Academy of Sciences | the positive conversion rate of neutralizing antibody was 99.06%, and the protective effect was 72.51% | – |
| Inactivated virus (BBIBP-CorV) | Beijing Institute of Biological Products, Sinopharm, with Institute of Viral Disease Control and Prevention | the positive conversion rate of neutralizing antibody was 99.52%, and the protective effect was 79.34% | roughly equivalent against B.1.1.7 spike-expressing recombinant virus, but 2.5-fold lower efficacy against virus expressing the B.1.351 spike (in vitro) |
| Virus vector (Ad5) | CanSino Biological Inc. with Beijing Institute of Biotechnology | a protective efficacy against all symptoms of 68.83% (phase III clinical trial) | – |
| Virus vector (ChAdOx1) | University of Oxford, with AstraZeneca | the protective effect was 76% (phase III clinical trial), although some thrombotic events occurred; no definitive causal relationship between vaccine and thrombosis was found | – |
| LNP-mRNA (mRNA-1273) | Moderna, with National Institute of Allergy and Infectious Diseases | 94.1% effective in phase III trial (95% CI: 89.3–96.8) | roughly equivalent against B.1.1.7 spike-expressing recombinant viruses, but 6.4-fold lower against B.1.351 spike-expressing virus |
| LNP-mRNA (BNT162b2) | BioNTech, with Fosun Pharma and Pfizer | 95% in a clinical trial involving ~44,000 participants; the effective rate for preventing severe illness is 100% | roughly equivalent against P.1 spike- and B.1.1.7 spike-expressing recombinant viruses, but ~2/3 reduction in efficacy against B.1.351 spike-expressing virus (in vitro study) |
| Protein subunit (NVX-CoV2733) | Novavax | 95.6% against the original strain (phase III trial in the UK) | 85.6% effective against the B.1.1.7 variant (phase III trial in the UK); the protective efficacy was 60% (95% CI: 19.9–80.1) with 93% of cases involving the B.1.351 variant (phase II trial in South Africa) |
| Virus-vectored (Ad26) | Janssen Pharmaceutical Company | 66.9% effective (95% CI: 59.0–73.4) | – |
| Protein subunit (ZF2001) | Anhui Zhifei Longcom Biopharmaceutical, with Institute of Microbiology, Chinese Academy of Sciences | the positive conversion rate was 96.6% in the phase II clinical trial, and the neutralizing antibody titer was 102.5 | geometric mean titer was 106.1 (95% CI: 75.0–150.1) against the original virus strain and 66.6 (95% CI: 51.0–86.9) against the B.1.351 variant |