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Home HPV Vaccines HPV Vaccines HPV Vaccination Doesn’t Cause “Type Replacement”

HPV Vaccination Doesn’t Cause “Type Replacement”

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When HPV vaccines were being developed, some researchers wondered if success in blocking infection with certain HPV types would potentially cause other types to rush in and fill the void (known as “type replacement”). The two vaccines on the market protect against infections related to a pair of “high risk” viral types found with most cervical cancers, HPV 16 and HPV 18. One of the vaccines also protects against the “low risk” types (HPV 6 and HPV 11, respectively) found with 90% of external genital warts.

Worries around type replacement were never too prominent with HPV vaccines, but did surface a number of times as vaccine efficacy (including cost effectiveness) was discussed. Fortunately, results from a study in Africa suggest type replacement isn’t an issue.

The subjects in this research were more than 2,700 males who were part of a circumcision trial in Kenya. The investigators, led by Dr. Anne Rositch of the Johns Hopkins Bloomberg School of Public Health, found that HPV vaccination did not encourage “competition” among different types of HPV, and appeared unlikely to result in non-vaccine types becoming more common. While more studies are needed to nail this down for certain, the results are encouraging and give a big boost to the “cost-effectiveness” of HPV vaccines, which would have been much weaker were vaccines shown to encourage other HPV types to simply step up as replacements. Read more here.

Reference:
Rositch A, Hudgens M, Backes D, Moses S, Agot K, Nyagya E, Snijders P, Meijer C, Bailey R, and Smith J. Vaccine-Relevant Human Papillomavirus (HPV) Infections and Future Acquisition of High-Risk HPV Types in Men. JID, 2012. 206(5): 669-677.