Table 2.
Effect of single-dose strategy with catch-up versus two-dose strategy without catch-up on cervical cancer risk, by vaccine protection assumption scenario
|
Relative reduction in lifetime risk, % |
Relative efficiency in cases prevented per dose (single dose vs two dose)* | Absolute number of cervical cancer cases prevented† | ||||
|---|---|---|---|---|---|---|
| Routine cohort‡ | Candidate catch-up cohort§ | Routine and candidate catch-up cohorts combined | ||||
| Two-dose vaccination without catch-up | ||||||
| A (life-long protection) | 71% (69–72) | 6% (4–7) | 38% (37–39) | NA | 1 055 193 | |
| Single-dose vaccination with catch-up | ||||||
| 60% coverage of catch-up vaccination | ||||||
| A (life-long protection) | 72% (71–73) | 42% (40–44) | 57% (56–58) | 80% | 1 582 790 | |
| B | 64% (62–66) | 38% (35–40) | 51% (49–53) | 61% | 1 416 181 | |
| C | 58% (56–61) | 33% (30–36) | 46% (44–48) | 45% | 1 277 339 | |
| D | 51% (49–53) | 28% (26–31) | 40% (38–41) | 26% | 1 110 730 | |
| E | 50% (48–52) | 28% (26–30) | 39% (37–40) | 23% | 1 082 962 | |
| 90% coverage of catch-up vaccination | ||||||
| A (life-long protection) | 73% (72–74) | 58% (55–60) | 65% (64–66) | 71% | 1 804 936 | |
| B | 66% (64–67) | 52% (49–54) | 59% (57–60) | 55% | 1 638 327 | |
| C | 60% (58–62) | 47% (45–49) | 53% (52–55) | 39% | 1 471 717 | |
| D | 52% (50–54) | 40% (38–42) | 46% (44–48) | 21% | 1 277 339 | |
| E | 51% (49–53) | 40% (37–42) | 46% (44–47) | 21% | 1 277 339 | |
Data are n, proportion, or proportion (80% uncertainty interval). Vaccine protection assumptions A–E are described in the appendix (pp 27–28). HPV=human papillomavirus. NA=not applicable.
Under 90% coverage in the catch-up cohorts, number of doses required in routine and catch-up cohorts combined is the same for both strategies, whereas under 60% coverage in the catch-up cohorts, number of doses required in routine and candidate catch-up cohorts combined is 1·2 times higher for the two-dose routine-only strategy than the single-dose strategy.
Absolute number of cases prevented in the routine and catch-up birth cohorts, combined with the total number of women born in India in 2000–20, which was estimated to be 260 million.
The first ten routine vaccination birth cohorts.
The ten birth cohorts aged 11–20 years at start of vaccination that could be vaccinated as part of catch-up programme.