COVID 19 Management CME Course Update: Variants April 2021
COVID 19 SarsCOV-2 Variants
Major Variants
UK B1.1.7 Sept 2020
- Spike protein mutation
- Increased transmission
- No increase in severity of disease
- No reduction in vaccine efficacy
South Africa B1.351 Oct. 2020
- Spike protein mutation
- Increased transmission
- No increased severity of disease
- Reduced vaccine infection prevention
- No reduction in vaccine severe disease prevention
Brazil P.1 Jan 2021
- Spike protein mutation
- Increased transmission
- No increased severity of disease
- Reduced vaccine infection prevention
- No reduction in vaccine severe disease prevention
Variants and Immunity: Cellular Immunity vs Humoral (Antibodies) Immunity
Cellular Immunity
NIH News Brief: Does the Immune System Recognize Variants April 2021
- CD8 T cells from COVID 19 convalescent patients NIH Research Reference
- UK B1.1.7 – positive recognition
- B 1.351 – positive recognition
- P.1 – Positive recognition
- Conclusion
- Cellular immunity in the form of T Cell immune response will be initiated to all variants.
- Infection is possible but severe disease very unlikely in all variants due to the cellular immunity response.
Antibody Immunity JAMA March 2021
- Previous infection: antibody levels are lower but likely still protective from infection and very likely from severe disease.
- Vaccination: Lower antibody response but still enough to prevent infection and severe disease.
- Vaccine boosters in development to cover emerging strains. (6- 12 months after initial vaccination)
- Specific vaccine clinical trials in variant populations pending
Anti-viral and Anti-inflammatory Treatments NEJM March 24, 2021
- No evidence that antiviral agents and anti-inflammatory treatments are any less effective with the emerging variants than with the preexisting variants, treatment with convalescent serum and monoclonal antibodies may not be as effective.
