Table 4 COVID-19 incidence based on adjudication committee assessments by variant waves for booster and non-booster participants (PP-primary series set)

From: Long-term safety and effectiveness of mRNA-1273 vaccine in adults: COVE trial open-label and booster phases

 

COVID-19

Severe COVID-19

Booster mRNA-1273 50 µg

N = 17,657a

Non-Booster

N = 7257a

Booster mRNA-1273 50 µg

N = 17,657a

Non-Booster

N = 7257a

September 1, 2021–November 30, 2021 (Delta predominant)

 Participants at risk (N1)

15,557

21,456

15,557

21,930

 Participants with event, n (%)b

32 (0.2)

272 (1.3)

2 (<0.1)

42 (0.2)

 Person-monthsc

19,874.5

40,108.7

19,900.3

41,500.1

 Incidence/1000 person-monthsd

1.61 (1.10–2.27)

6.78 (6.00–7.64)

0.10 (0.01–0.36)

1.01 (0.73–1.37)

 Incidence reduction, % (95% CI)e

76.3 (65.7–84.1)

90.1 (61.8–98.8)

December 1, 2021–March 31, 2022 (Omicron BA.1 predominant)

 Participants at risk (N1)

17,549

3258

17,579

3530

 Participants with event, n (%)b

1553 (8.8)

234 (7.2)

79 (0.4)

13 (0.4)

 Person-monthsc

63,229.6

5047.5

66,803.2

5957.9

 Incidence/1000 person-monthsd

24.56 (23.36–25.81)

46.36 (40.61–52.70)

1.18 (0.94–1.47)

2.18 (1.16–3.73)

 Incidence reduction, % (95% CI)e

47.0 (39.0–53.9)

45.8 (−6.3–70.1)

April 1, 2022–June 30, 2022 (Omicron BA.2 predominant)

 Participants at risk (N1)

15,044

670

16,541

862

 Participants with event, n (%)b

1181 (7.9)

19 (2.8)

52 (0.3)

1 (0.1)

 Person-monthsc

38,329.6

1840.1

43,691.6

2413.6

 Incidence/1000 person-monthsd

30.81 (29.08–32.62)

10.33 (6.22–16.12)

1.19 (0.89–1.56)

0.41 (0.01–2.31)

 Incidence reduction, % (95% CI)e

−198.4 (−397.4 to −90.2)

−187.3 (−11,461.5–50.7)

July 1, 2022–November 30, 2022 (Omicron BA.4/5 predominant)

 Participants at risk (N1)

10,884

569

13,294

767

 Participants with event, n (%)b

969 (8.9)

20 (3.5)

41 (0.3)

0

 Person-monthsc

28,660.7

1753.7

37,188.3

2347.3

 Incidence/1000 person-monthsd

33.81 (31.71–36.01)

11.41 (6.97–17.61)

1.10 (0.79–1.50)

0.00 (NE–1.57)

 Incidence reduction, % (95% CI)e

−196.5 (−387.5 to −90.9)

NE (NE-NE)

After December 1, 2022 (Omicron BQ.1.1 predominant)

 Participants at risk (N1)

268

69

348

75

 Participants with event, n (%)b

1 (0.4)

0

0

0

 Person-monthsc

127.9

45.4

165.2

49.2

 Incidence/1000 person-monthsd

7.82 (0.20–43.57)

0.00 (NE–81.30)

0.00 (NE–22.34)

0.00 (NE–74.90)

 Incidence reduction, % (95% CI)e

NE (NE–NE)

NE (NE–NE)

  1. CI confidence interval, COVID-19 coronavirus disease 2019, NE not estimable, PP per-protocol.
  2. For N1 in each time period, a participant who received a booster was included in the non-booster column for the period(s) before booster, and in the booster column for the period(s) after booster. For participants with event(s) before booster and event(s) after booster, the first event after the first injection of the mRNA-1273 100-µg primary series and before booster is counted in the non-booster column; and the first event after booster is counted in the booster column. Participants who received a booster after the primary series were compared with those who had not received a booster after the primary series during the time period.
  3. aN in the header presents total number of participants receiving a booster or not receiving a booster as of data-cutoff date. Participants who received a booster before the end of study participation or data-cutoff date are included in the booster group; otherwise, participants are included in the non-booster column.
  4. bPercentages based on N1. For N1, participants who received a booster are included in the non-booster column for the period(s) pre- and post-booster. For participants with event(s) pre- and post-booster, the first event after the first injection of the mRNA-1273 100-µg primary series and before booster is counted in the non-booster column; and the first event after booster is counted in the booster column.
  5. cFor the booster column, person-months is defined as the total months from the start of each time period or the date of booster, whichever is later, to the date of the first event after booster, the end of each time period, last date of study participation, or effectiveness data-cutoff date, whichever is the earliest. For the non-booster column, person-months for each time period is defined as the total months from the start of each time period to the date of the first event after the first injection of mRNA-1273 100-µg primary series, the end of each time period, last date of study participation, or effectiveness data-cutoff date, (or one-day pre-booster date if received), whichever is the earliest.
  6. dIncidence for each time period is defined as the number of participants with an event during the time period divided by the number of participants at risk during the time period and adjusted by person-months (total time at risk) in each treatment group. 95% CI is calculated using the exact method (Poisson distribution) and adjusted by person-months.
  7. eReduction in incidence rate is defined as 1−ratio of incidence rate (booster vs non-booster) and 95% CI of the ratio was calculated using the exact method conditional upon the total number of cases, adjusting for person-months for the time period.
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