Table 1 Vaccine efficacy in South Africa and the Gauteng province, calculated for three time periods: June 18th to July 18th (Jun–Jul), August 9th to September 6th (Aug–Sep), and December 1st to 31st (Dec).

From: Using survey data to estimate the impact of the omicron variant on vaccine efficacy against COVID-19 infection

Method

Jun–Jul efficacy [95% CI]

Aug–Sep efficacy [95% CI]

Dec efficacy [95% CI]

South Africa

 Vaccinated

  Random Forest

0.54 [0.48, 0.59]

0.62 [0.58, 0.65]

0.24 [0.17, 0.30]

  UMD CLI

0.60 [0.53, 0.66]

0.66 [0.61, 0.70]

0.46 [0.39, 0.51]

  Stringent CLI

0.69 [0.63, 0.74]

0.70 [0.66, 0.73]

0.48 [0.40, 0.55]

  Classic CLI

0.55 [0.50, 0.59]

0.56 [0.52, 0.59]

0.38 [0.33, 0.43]

  Broad CLI

0.50 [0.44, 0.54]

0.49 [0.44, 0.52]

0.36 [0.30, 0.41]

 Vaccinated with one dose

  Random Forest

0.50 [0.44, 0.56]

0.51 [0.46, 0.55]

0.09 [0.00, 0.18]

  UMD CLI

0.61 [0.54, 0.68]

0.56 [0.50, 0.62]

0.21 [0.09, 0.31]

  Stringent CLI

0.67 [0.61, 0.73]

0.60 [0.54, 0.65]

0.23 [0.07, 0.36]

  Classic CLI

0.53 [0.47, 0.57]

0.47 [0.42, 0.51]

0.21 [0.13, 0.28]

  Broad CLI

0.46 [0.40, 0.52]

0.39 [0.34, 0.44]

0.18 [0.09, 0.26]

 Vaccinated with two doses

  Random Forest

0.76 [0.64, 0.84]

0.81 [0.78, 0.84]

0.30 [0.23, 0.36]

  UMD CLI

0.75 [0.57, 0.86]

0.85 [0.79, 0.88]

0.56 [0.50, 0.61]

  Stringent CLI

0.82 [0.66, 0.90]

0.88 [0.84, 0.91]

0.59 [0.51, 0.65]

  Classic CLI

0.77 [0.66, 0.84]

0.71 [0.67, 0.75]

0.45 [0.40, 0.49]

   Broad CLI

0.75 [0.63, 0.83]

0.66 [0.61, 0.71]

0.43 [0.37, 0.48]

Gauteng

 Vaccinated

  Random Forest

0.43 [0.33, 0.51]

0.62 [0.54, 0.69]

0.30 [0.18, 0.40]

  UMD CLI

0.58 [0.44, 0.68]

0.63 [0.51, 0.73]

0.52 [0.41, 0.61]

  Stringent CLI

0.64 [0.53, 0.72]

0.70 [0.61, 0.78]

0.57 [0.43, 0.67]

  Classic CLI

0.50 [0.42, 0.58]

0.51 [0.42, 0.59]

0.48 [0.39, 0.55]

  Broad CLI

0.49 [0.39, 0.57]

0.41 [0.31, 0.50]

0.45 [0.35, 0.53]

 Vaccinated with one dose

  Random Forest

0.40 [0.28, 0.49]

0.54 [0.44, 0.63]

0.14 [0.00, 0.30]

  UMD CLI

0.60 [0.46, 0.71]

0.58 [0.42, 0.70]

0.38 [0.18, 0.53]

  Stringent CLI

0.62 [0.49, 0.71]

0.61 [0.47, 0.71]

0.39 [0.13, 0.57]

  Classic CLI

0.47 [0.37, 0.56]

0.47 [0.36, 0.56]

0.35 [0.20, 0.46]

  Broad CLI

0.44 [0.33, 0.53]

0.34 [0.20, 0.45]

0.29 [0.14, 0.42]

 Vaccinated with two doses

  Random Forest

0.62 [0.36, 0.78]

0.77 [0.67, 0.85]

0.36 [0.24, 0.46]

  UMD CLI

0.69 [0.27, 0.87]

0.73 [0.54, 0.84]

0.57 [0.45, 0.66]

  Stringent CLI

0.85 [0.55, 0.95]

0.88 [0.76, 0.94]

0.65 [0.51, 0.74]

  Classic CLI

0.79 [0.59, 0.90]

0.58 [0.44, 0.68]

0.53 [0.44, 0.60]

  Broad CLI

0.80 [0.59, 0.91]

0.54 [0.39, 0.65]

0.50 [0.41, 0.58]

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