Australia introduced the national quadrivalent human papillomavirus (4vHPV) vaccination programme in mid-2007 in young women. The aim of this study was to examine the trend in prevalence of vaccine targeted HPV types contained in 4vHPV and the nine-valent (9vHPV) vaccines among sexually active heterosexual men, and to investigate whether men are protected by herd protection from the universal female vaccination programme.
A total of 1,466 heterosexual men aged ≤25 attending Melbourne Sexual Health Centre between 1 July 2004 and 30 June 2015 diagnosed with Chlamydia trachomatis were included. Detection of HPV genotypes was performed using the PapType high-risk HPV detection and genotyping kit on stored urine or urethral swab samples. The prevalence of any HPV types, 4vHPV types (6/11/16/18) and the additional types present in the 9vHPV (31/33/45/52/58 alone) were calculated for each Australian financial year and stratified by age, vaccine eligibility, and country of birth.
The proportion of samples with 4vHPV types dramatically dropped from 20% [95% CI: 10-33%] in 2004/05 to 3% [0-11%] in 2014/15 (ptrend<0.001) among 633 Australian-born men; and a greater decline was observed in 237 Australian-born men aged ≤21 years old (from 31% [9-61%] to 0% [0-14%]; ptrend <0.001) in the last 11 years. No temporal changes were observed in any HPV types and in types 31/33/45/52/58 in Australia-born men.
A significant decline in HPV 16/18 (from 18% [6-37%] to 4% [1-9%]; ptrend=0.014), but not in HPV 6/11 (from 11% [2-28%] to 4% [1-9%]; ptrend=0.319) was seen among overseas-born men. Of the 258 overseas-born men who arrived in Australia from a country that introduced the bivalent vaccine programme (predominantly the UK), the prevalence of HPV16/18 dropped from 17% [6-36%] to 10% [6-14%] between pre- and post-vaccination period (p=0.017), but there was no change in HPV 6/11 (from 7% [1-23%] to 6% [3-10%]; p=0.260). There was also no change in 4vHPV types in men from a country without a vaccination programme.
There has been a fall in prevalence of 4vHPV among unvaccinated Australia-born men, suggests men receive herd protection from the universal female programme. In addition, the decline in HPV 16/18, but not HPV 6/11 in overseas-born males predominantly from a country with a bivalent vaccine programme, suggests these men receive benefits from herd protection for 16/18 from their vaccinated female partners in their own countries.