Table 2 Effectiveness in individuals aged 18–64 years in the B.1.617.2-dominant period

From: Effect of Delta variant on viral burden and vaccine effectiveness against new SARS-CoV-2 infections in the UK

VE (95% CI)

BNT162b2: one dose ≥21 d

ChAdOx1: one dose ≥21 d

BNT162b2: second dose 0–13 d ago

ChAdOx1: second dose 0–13 d ago

BNT162b2: second dose ≥14 d

ChAdOx1: second dose ≥14 d

Not vaccinated, previously positivea

All infections (Fig. 1a)

58% (51–63%)

43% (31–52%)

83% (76–88%)

71% (63–77%)

82% (79–85%)

67% (62–71%)

73% (59–82%)

Ct <30 (Fig. 1b)

63% (57–68%)

48% (38–57%)

81% (73–86%)

69% (61–76%)

86% (84–88%)

69% (65–73%)

78% (66–85%)

Self-reported symptoms (Fig. 1c)

59% (52–64%)

36% (23–47%)

93% (90–95%)

72% (65–78%)

86% (83–88%)

70% (66–74%)

83% (74–88%)

Ct ≥30

40% (31–48%)

27% (12–39%)

87% (82–91%)

74% (66–79%)

71% (65–75%)

59% (53–64%)

57% (35–72%)

No self-reported symptoms

55% (48–61%)

50% (40–58%)

58% (41–70%)

66% (57–73%)

74% (69–78%)

57% (51–63%)

51% (26–67%)

  1. aRe-infection will be a variable amount of time previously, but it was not possible to split this owing to low numbers.
  2. Note: All estimates (VE = 100% × (1 odds ratio)) as shown in Fig. 1 were obtained from a generalized linear model with a logit link comparing to the reference category of ‘Not vaccinated, not previously positive and ≥21 d before vaccination’ and using clustered robust standard errors. Heterogeneity P values were obtained using the two-sided Wald test without adjustment for multiple comparisons. See Supplementary Table 5 for unadjusted heterogeneity P values. See Table 1 for estimates in individuals ≥18 years of age in both B.1.1.7-dominant and B.1.617.2-dominant periods. VE post-second doses changes over time from vaccination (Fig. 2 and Extended Data Figs. 4 and 5), so estimates in this table are an average over follow-up included in this analysis.
Back to article page