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HPV-vaccines – a breakthrough in medicine. Björn Strander Onkologiskt centrum Västra regionen and Kungsbacka Närsjukhus Sweden. Cervical cancer. ”Unusual complication to persistent infection with high risk HPV”. 2 vaccines. Gardasil – MSD Quadrivalent HPV 6,11,16,18
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HPV-vaccines – a breakthrough in medicine Björn Strander Onkologiskt centrum Västra regionen and Kungsbacka Närsjukhus Sweden
Cervical cancer ”Unusual complication to persistent infection with high risk HPV”
2 vaccines • Gardasil – MSD • Quadrivalent HPV 6,11,16,18 • Approved by European agency in september 2006 • Cervarix – GSK • Bivalent HPV 16, 18 • Approved by European agency in september 2007
VLP vaccines • High antibody levels – VLPs injected i.m. give good access to lymphatics and draining lymph nodes where antibody responses are initiated and memory cells develop • VLPs are very immunogenic, activating antigen presenting cells and B- and T-cells
Duration of Efficacy Evaluation • The duration of efficacy of HPV-vaccines have not been determined • High efficacy of vaccines was observed through 4,5 - 5 years of follow-up • Minimum protective anti-HPV level has not been defined • No breakthroughs due to waning immunity • Antibodies remain quite stable through 4,5 - 5 years • Vaccines induces immune memory responses
HPV 16/18-Related Cervical, Vulvar, Vaginal Cancer Efficacy (Via Surrogates) Per-Protocol Efficacy Population Follow up 3 years
Evidence of cross reactivity • Gardasil: 38% efficacy against CIN2+ containing 10 non-16/18 high risk HPV-types • Cervarix: 27% protection against 12 months persistent infection with 12 non-16/18 hrHPV-types
GardasilCases PlaceboCases %Efficacy Endpoint 95% CI Efficacy for all CIN2+ in population neg HPV 6/11/16/18 and with negativ cytologi at baseline Expected Efficacy without cross reactivity= 99% x 0.52 = 51% 2.4 years follow up CIN2-3 or AIS 52 97 46 24, 62
Sweden • Life time risk for cervical cancer 0.7% • Can be reduced to 0.25% with screening + vaccination • NNT for preventing 1 case of cervical cancer ~ 200 • NNT for saving 1 life ~ 600 • Other estimates 618 - 11251 1 Brisson et al CMAJ aug 2007
Numbers needed to vaccinate to save one life • Varicellae 34 000 • Meningococcus 21 000 • Influenza 5 000 Vaccinating people > 65 years of age
HPV and cancer Cancer % associated Number in Sweden 2005 HPV HPV 16/18 Cervix ≥95% 70% 429 Vagina 60% 55% 46 Vulva 40% 30% 128 Penis 40% 25% 80 Anus 90% 80% 130 Head and neck 20% 18% 579 489 Number of female cancers that could be prevented with HPV 16/18 vaccination Non-cervical in proportion of cervical cancers 63 % Parkin, Bray Vaccine. 2006 Aug 21;24 Socialstyrelsen Cancerstatistik www.sos.se Accessed 070315
HPV vaccinesAdvantages – world wide • Breakthrough in prevention of cervical cancer • Can offer the protection for third world women with minimum side effects • Can have dramatic effect on incidence and mortality on a world scale
HPV vaccinesAdvantages – Nordic countries • Mass vaccination of girls in school can reach those who will not attend screening • Will reduce mortality in cerival cancer • Less treatment of cancer and dysplasia will give benefits in fertility and pregnancy losses • Reduced anxiety associated with cancer and dysplasia • Reduction of other cancers are to expect • Reduction of warts (Gardasil) • Not more serious adverse events than placebo • Boys/men can benefit from herd immunity
HPV vaccinesConcerns • Cost • Prevent improvement of existing screening? • Need of booster vaccination? • Efficacy against cancer? • will type replacement occur? • Implementation in the third world • women hostile cultures