A national school-based HPV vaccination programme for girls aged 12-13 years old was introduced in the UK in September 2008 offering the bivalent HPV 16/18 vaccine. In 2012, the programme changed to offer the quadrivalent vaccine, additionally protecting against HPV types 6 and 11, responsible for approximately 90% of genital warts (GW). Coverage for the vaccination programme has been high, with over 85% of routine cohorts completing all doses. Previously reported data have shown modest declines in GW diagnoses, suggesting a potentially cross-protective effect of the bivalent vaccine against GW. We present the first evidence of declines in GW diagnoses following the programme change to the quadrivalent vaccine.
Data were obtained from the GUM Clinic Activity Dataset (GUMCADv2) submitted by GUM and integrated GUM/sexual and reproductive health clinics for years 2009-2016. GUMCADv2 is a mandatory reporting system, providing disaggregate records of all attendances, testing and diagnoses at GUM clinics in England and has been reported to Public Health England (PHE) since 2008, with full coverage from 2009. All records coded as first episode GW for females and males aged 15-24 years old were extracted. Diagnoses of recurrent GW were excluded.
Data to end 2015 – available at abstract submission: In 2015, 254,775 and 77,584 attendances were recorded by GUMCADv2 in 15-19 year old females and males, respectively. The rate of GW diagnoses for females aged 15 to 19 years was 38.9% lower (from 685.8 to 419.2 per 100,000 population) in 2015 than in 2009, and 30.2% lower (from 274 to 191.2 per 100,000 population) for 15-19 year old males. Over the same time period, the greatest declines were observed in 15 year old females (83.2%) and 16 year old females (58.0%); around 2/3 of vaccinated 15 year olds and 1/6 of vaccinated 16 year olds would have received the quadrivalent vaccine. Reductions in the rate of GW diagnoses among same aged males were 31.6% and 32.7%. Decreases of 17.5% (from 698.9 to 576.8 per 100,000 population) and 15.5% (from 849.6 to 718.2 per 100,000 population) were seen in 20-24 year old females and males, respectively.
The moderate, unexpected declines in GW that we have seen since the introduction of a high coverage HPV vaccination programme using the bivalent vaccine are being followed, as expected, by much larger declines amongst females offered the quadrivalent vaccine.
These ecological observations suggest that the high coverage female-only HPV vaccination programme is affording substantial herd protection to young males.
We will present analyses including data to end 2016 (available in June 2017), with additional sub-group analyses.