(HealthDay News) — There is no increased risk of venous thromboembolism (VTE) after quadrivalent human papillomavirus (HPV) vaccination, according to a research letter published in the Journal of the American Medical Association.
Nikolai Madrid Scheller, from the Statens Serum Institut in Copenhagen, Denmark, and colleagues examined the potential link between quadrivalent HPV vaccination and VTE using data from Danish national demographic and health care registers.
A source population of 1,613,798 women, aged 10 through 44 years from Oct. 1, 2006, through July 31, 2013, was constructed; 31% received the quadrivalent HPV vaccine.
The researchers identified 4,375 incident cases of VTE in the source population. Of these, 20% were vaccinated during the study period. During the 42 days following vaccination there was no correlation between the quadrivalent HPV vaccine and VTE (crude incidence rates, 0.126 and 0.159 events/person-year for risk and control periods, respectively; incidence ratio, 0.77; 95% confidence interval, 0.53 to 1.11).
There was no association noted in subgroup analyses by age, including only anticoagulant-treated cases, only exposed cases, or after adjustment for oral contraceptive use.
“Our results, which were consistent after adjustment for oral contraceptive use and in girls and young women as well as mid-adult women, do not provide support for an increased risk of VTE following quadrivalent HPV vaccination,” the researchers wrote.
- Scheller NM, Pasternak B, Svanström H, et al. Quadrivalent Human Papillomavirus Vaccine and the Risk of Venous Thromboembolism. JAMA. 2014;312(2):187-188.