Archive · 12 Jan 2026
HPV Vaccination Shows Herd Protection in Sweden
A study from Sweden shows that when many girls are vaccinated against HPV, even those who aren't vaccinated get some protection.
This is called herd immunity.
The study looked at different groups of women born between 1989 and 2000.
They found that in the group where 80% of girls were vaccinated, unvaccinated women had half the risk of serious pre-cancerous changes compared to groups with lower vaccination rates.
This means that vaccinating many girls can help protect everyone, including those who didn't get the vaccine.
In India, where cervical cancer is a big problem, this could be a important lesson for starting school-based HPV vaccination programs.
High HPV vaccination coverage in Sweden reduced pre-cancerous lesions in both vaccinated and unvaccinated women.
The study found that unvaccinated women in the 1999-2000 cohort had half the risk of serious pre-cancerous changes compared to those in the 1985-1988 cohort.
India is considering a school-based HPV vaccination program for girls aged 9 to 14.
The vaccine is most effective when administered before girls become sexually active.
High vaccination coverage in India could lead to a reduction in cervical cancer incidence and the need for fewer diagnostic tests.
- Who
- Unvaccinated women in Sweden
- What
- Reduction in pre-cancerous lesions due to herd protection from HPV vaccination
- When
- Study conducted on cohorts born between 1989 and 2000
- Where
- Sweden
- Why
- High vaccination coverage in school-based programs leads to herd immunity, reducing cancer risk in unvaccinated individuals
- Study Location
- Sweden
- Vaccination Coverage (1989-92)
- 25%
- Vaccination Coverage (1993-98)
- 55%
- Vaccination Coverage (1999-2000)
- 80%
- Incidence in 1989-92 Cohort
- 1.17 per 1,000 person years
- Incidence in 1993-98 Cohort
- 1.06 per 1,000 person years
- Incidence in 1999-2000 Cohort
- 0.54 per 1,000 person years
- HPV Types Covered by Vaccine
- 16, 18, 6, 11
