Table 3.
Summary of data on features, acquired cluster of S-protein mutations, and vaccine efficacy studies for the major COVID-19 variants of concern.
| Names (PANGOLIN, Nexstrain, Media) | Features | Notable mutations in S-Protein | Vaccine efficacy reduction | Countries reported (n) as of August 17, 2021 | References |
|---|---|---|---|---|---|
| B.1.1.7, 20I/501.Y.V1, VOC/20201201, UK strain (Alpha Variant) |
• Increased binding to ACE2 receptor • 30–70% increased transmissibility • Realistic possibility of increased severity Reproduction rate [range 1.5–1.7] • Higher nasal viral load and increased shedding, prolonged viral shedding, and heighten stability in the current environment • Decreased neutralization |
• N501Y • HV69-70 del • P681H • Y144 del, • A570D • E484K • D614G |
• Efficacy data • Novavax 86% • Pfizer/BioNTech Single dose 47.5% (95% CI: 41.6–52.8) • Pfizer/BioNTech Dual dose 93.7% (95% CI: 91.6–95.3) • AstraZeneca Single dose 48.7% (95% CI: 45.2–51.9) • AstraZeneca dual dose 74.5% (95% CI: 68.4–79.4) • Mean loss in neutralization: • At day 43 after dual doses at day 28 • Moderna (n = 12): 1.8-fold • Pfizer/BioNTech (n = 10): 2-fold |
190 | 64,77 –81 |
| B.1.351, 20H/501.Y.V2, South African strain (Beta Variant) |
• Increased severity • Increased transmission • Reinfection is possible as the convalescent immunity cannot mount a response against this new variant |
• E484K • K417N • N501Y • D614G orf1b deletion |
• Efficacy data • Janssen Vaccine (moderate to severe at day 28) 64.0% (95% CI: 41.2–78.7) • Janssen Vaccine (Severe at day 28) 81.7% (95% CI: 46.2–95.4) • Novavax Dual dose 60.1% (95%CI: 19.9–80.1) • AstraZeneca Dual dose 10.4% (95% CI: −76.8 to 54.8) • Mean loss in neutralization compared to wild type: • Moderna (n = 12): 8.6-fold • Pfizer/BioNTech (n = 10): 6.5-fold • BBIBP-CorV: 10-fold |
138 | 20,28,79,81 –84 |
| Lineage P.1, B.1.1.28.1, Brazilian strain (Gamma Variant) |
• Increased severity • Increased transmissibility • Documented case of reinfection |
• N501Y • E484K • D614G • K417N/T • orf1b deletion |
• Pfizer/BioNTech: Significant reduction in
neutralization • Moderna: Significant reduction in neutralization • SinoVac: seroconversion and geometric mean titres in the neutralizing antibody assays |
82 | 26,81,85,86 |
| B.1.617.2 Indian Strain (Delta Variant) |
• Increase transmission • Decrease neutralization |
• L452R • D614R • P681R |
• Efficacy data • Pfizer/BioNTech Single dose 35.6% (95% CI: 22.7–46.4) • Pfizer/BioNTech Dual dose 88.0% (95% CI: 85.3–90.1) • AstraZeneca Single dose 30.0% (95% CI: 24.3–35.3) • AstraZeneca Dual dose 67.0% (95% CI: 61.3–71.8) • BBV152 Dual Dose 65·2% (95% CI: 33·1–83·0) • Mean loss in neutralization compared to wild type: • BBIBP-CorV: 1.38- fold |
148 | 80,81,87 |
CI, confidence interval; COVID-19, coronavirus disease 2019; VOC, variants of concern.