CDC ACIP slides 1/27/2021

[M_T]

There is an interesting set of slides from an ACIP working group dated 1/27/2021.

Efficacy estimate for the dual standard-dose regimen of the AZ vaccine is 62% (41-75%).  Pooled with the low-dose/standard-dose regimen, the overall estimate of efficacy is 70.4% (55-81%).  32,000 people will be in US Phase III trials (2 equal doses), and that will be what is used for judging it.

Regarding different strains:

Following vaccination, study participant sera (n=8–20) tested in neutralization assays:

• Pfizer BioNTech COVID-19 vaccine: 
  • Several studies have demonstrated equivalent neutralizing titers against a panel of 19 individual  SARS-CoV-2 spike variants1  and N501Y (variant)2 compared to wildtype virus
    
  • Reductions to neutralizing titers have been noted against the B.1.1.7 (UK) variant (all mutations):
    • 1.3-fold average reduction3
      
    • 3.9-fold median reduction4
      
  • One study with modest reduction (<3-fold) for some with neutralization against certain SARS-CoV-2 spike mutations from B.1.351 (South African) and P.1 (Brazil) variants: E484K and K417N:E484K:N501Y5
    
• Moderna COVID-19 Vaccine:
  • One study with modest reduction (<3-fold) for some with neutralization against certain SARS-CoV-2 spike mutations from B.1.351 (South African) and P.1 (Brazil) variants: E484K and K417N:E484K:N501Y5
    
  • Another study with no significant impact on neutralizing titers against B.1.1.7 (UK) variant, but 6-fold reduction for B.1.351 (South African) variant
    

Moderna has announced they are developing a vaccine against B.1.351 (South African) variant

Efficacy after dose 1 Phase III data

• Pfizer-BioNTechCOVID-19 vaccine
  • Most (98%) recipients received 2 doses of the Pfizer-BioNTech vaccine
    
  • Efficacy of 52.4% (29.5–68.4%) noted between dose 1 and dose 2
    
  • Additional data in UK press statement (not included in submission to FDA or CDC):
    • Cases from day 15-day 21: VE of 89% (52-97%)
      
    • Follow-up only until day 21
      
• Moderna COVID-19 vaccine
  • Most (97%) recipients received 2 doses of the Moderna vaccine
    
  • Efficacy of 69.5% (43.5–84.5%) noted between dose 1 and dose 2
    
  • Additional data from Moderna Phase III trial: 
    • Non-randomized sample of persons who only received 1 dose: VE of 92% (66–98%), 
      
    • Median follow-up only 28 days