HPV16 seroprevalence at the first pregnancy, number of seroconversions, and attack rates in age stratified primiparous women resident in the Helsinki metropolitan area during 1983–9 (A) and 1990–6 (B)
| Age group (years) | No of women | No (%) of seropositives | No of seroconversions | Attack rate (%) |
|---|---|---|---|---|
| A | ||||
| ≤17 | 46 | 13 (28.3) | 3 | 9.1 |
| 18–19 | 186 | 52 (28.0) | 10 | 7.5 |
| 21 | 153 | 36 (23.5) | 3 | 2.6 |
| 23 | 183 | 31 (16.9) | 6 | 3.9 |
| 25 | 92 | 18 (19.6) | — | — |
| 30 | 90 | 25 (27.8) | 1 | 1.5 |
| B | ||||
| ≤17 | 139 | 27 (19.4) | 17 | 15.2 |
| 18–19 | 196 | 44 (22.5) | 10 | 6.6 |
| 21 | 188 | 45 (23.9) | 3 | 2.1 |
| 23 | 191 | 49 (25.7) | 1 | 0.7 |
| 25 | 97 | 17 (17.5) | 2 | 2.5 |
| 30 | 95 | 30 (31.6) | 1 | 1.5 |