Table 2.
Exploratory analysis of vaccine efficacy against variants in the COVE trial PP set starting 14 days after the second dose
| COVID-19 variant cases in COVE | Placebo | mRNA-1273 |
|---|---|---|
| n = 14,164 | n = 14,287 | |
| COVID-19 primary efficacy endpointa, n (%) | 744 (5.3) | 55 (0.4) |
| Vaccine efficacy based on hazard ratio (95% CI)b | 93.2 (91.0–94.8) | |
| Incidence rate per 1,000 person-years (95% CI)c,d | 136.6 (127.0–146.8) | 9.6 (7.2–12.5) |
| COVID-19 with Epsilon and Gamma variants, n (%)a | 16 (0.1) | 3 (<0.1) |
| Number with competing events, n (%) | 728 (5.1) | 52 (0.4) |
| Vaccine efficacy based on hazard ratio (95% CI)b | 82.4 (40.4–94.8) | |
| Incidence rate per 1,000 person-years (95% CI)c,d | 2.9 (1.7–4.8) | 0.52 (0.11–1.5) |
| COVID-19 with Zeta variant, n (%)a | 2 (<0.1) | 0 |
| Number with competing events, n (%) | 742 (5.2) | 55 (0.4) |
| Vaccine efficacy based on hazard ratio (95% CI)b | 100.0 (NE–100.0) | |
| Incidence rate per 1,000 person-years (95% CI)c,d | 0.38 (0.04–1.4) | – |
| COVID-19 with Epsilon variants first detected (CA), n (%)a,e | 15 (0.1) | 3 (<0.1) |
| Number with competing events, n (%) | 729 (5.1) | 52 (0.4) |
| Vaccine efficacy based on hazard ratio (95% CI)b | 81.2 (36.1–94.5) | |
| Incidence rate per 1,000 person-years (95% CI)c,d | 2.8 (1.5–4.5) | 0.52 (0.11–1.5) |
| COVID-19 with Epsilon (B.1.429) variant first detected (CA), n (%)a | 9 (0.1) | 3 (<0.1) |
| Number with competing events, n (%) | 735 (5.2) | 52 (0.4) |
| Vaccine efficacy based on hazard ratio (95% CI)b | 68.9 (–12.8 to 91.4) | |
| Incidence rate per 1,000 person-years (95% CI)c,d | 1.7 (0.8–3.2) | 0.52 (0.11–1.6) |
Variants include Epsilon (B.1.427, B.1.429), Gamma (P.1) and Zeta (P.2). CA, California; NE, not estimable. COVID-19 cases with variant lineages other than the specified variant(s) assessed are considered as competing events.
aBased on participants with adjudicated assessments starting 14 days after second injection in the PP set, with censoring rules for efficacy analysis. If participant had a positive RT–PCR at the pre-dose 2 visit (day 29) without eligible symptoms for 14 days, or positive (Elecsys NP) at scheduled visits before becoming a COVID-19 case, the participant was censored at the date of positive RT–PCR or Elecsys NP.
bVaccine efficacy, defined as 1 – hazard ratio (mRNA-1273 versus placebo), and 95% CI estimated using Fine and Gray’s subdistribution hazard model, with disease cases as competing events and treatment group as a covariate, adjusting for stratification factor.
cPerson-years is defined as either total years from randomization date to the earliest among date of symptomatic SARS-CoV-2 infection, date of asymptomatic SARS-CoV-2 infection, last date of study participation and efficacy data cutoff.
dIncidence rate is defined as the number of participants with an event divided by the number of participants at risk and adjusted by person-years (total time at risk) in each treatment group; 95% CI was calculated using the exact method (Poisson distribution) and adjusted by person-years.
eIncludes Epsilon variants B.1.427 and B.1.429, which were originally categorized as VOCs then reconsidered as VOIs and now as variants being monitored (VBM) by the CDC. Variant Gamma P.1 was formerly considered a VOC, but now a VBM.