A New Zealand study found decrease in genital warts in females more as compared to males but the data in men is not very appreciable (Oliphant 2017).
Another Australian study found marked declines in genital warts in both sexes after introduction of HPV Vaccine (Ali et al. 2017).
A Spanish study found more decrease in genital warts in females given quadrivalent as compared to bivalent vaccines (Navarro-Illana et al. 2017).
Another study in PloS One found 61% fall in genital warts in women given HPV Vaccine (Harrison et al. 2014).
Flat warts are caused by HPV strains that are not the part of HPV Vaccine. Genital warts are caused by 90% by type 6 and 11.
Gardasil is a quadrivalent vaccine protecting against type 6, 11, 16 and 18
There is another vaccine trial going on that is 9 valent by Merck and Co. it protects against type 6, 11, 16, 18, 31, 33, 45, 52 and 58 (Petrosky 2017).
Ali et al. 2017. Human papillomavirus vaccination and genital warts in young Indigenous Australians: national sentinel surveillance data. The Medical journal of Australia 206(5), pp. 204–209.
Harrison et al. 2014. Decreased Management of Genital Warts in Young Women in Australian General Practice Post Introduction of National HPV Vaccination Program: Results from a Nationally Representative Cross-Sectional General Practice Study. PLoS ONE 9(9), p. e105967. doi: 10.1371/journal.pone.0105967.
Navarro-Illana et al. 2017. Effectiveness of HPV vaccines against genital warts in women from Valencia, Spain. Vaccine 35(25), pp. 3342–3346. doi: 10.1016/j.vaccine.2017.04.080.
Oliphant 2017. Trends in genital warts diagnoses in New Zealand five years following the quadrivalent human papillomavirus vaccine introduction – New Zealand Medical Journal. Available at: http://www.nzma.org.nz/journal/read-the-journal/all-issues/2010-2019/2017/vol-130-no-1452-24-march-2017/7191.
Petrosky 2017. Use of 9-Valent Human Papillomavirus (HPV) Vaccine: Updated HPV Vaccination Recommendations of the Advisory Committee on Immunization Practices. Available at: https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6411a3.htm.