Practical or Empty
[SaneVax: How are government health officials supposed to make sound decisions regarding HPV vaccine campaigns when all of the facts are not in? How much present risk is acceptable in the quest to try and prevent the possibility of future disease? Each unanswered question means less risk is acceptable. When injecting a healthy teen population hoping to prevent a disease decades down the road, no risk is acceptable. How does one tell if the benefits outweigh the risks?]
We need to talk about HPV vaccination – seriously
By Charlotte Haug, editor-in-chief, The Journal of the Norwegian Medical Association
(excerpt, NewScientist article) One way forward is to build a mathematical model of the disease and use it to test the benefits of vaccination. Doing so is extremely complex, however. The model has to factor in the natural history of HPV infection, the effect of the vaccine over a lifetime, the effect on other HPV strains, the effect of the vaccine on natural immunity against HPV, the sexual behaviour of the girls and women and their partners, and finally, cervical-cancer screening practices.
The modelling has been done (The New England Journal of Medicine, vol 359, p 821) and suggests that vaccinating 12-year-old girls is worth it. However, the model includes a number of highly optimistic assumptions. Among these are that the vaccine offers lifelong protection with no need for a booster, that it has the same effect on young girls as older women, that HPV-16 and HPV-18 are not replaced by other cancer-causing strains, that vaccinated women continue getting screened for cervical cancer, and that natural immunity against HPV is unaffected.
Are these assumptions reasonable? We do not know. What we do know is that if they are not, vaccination is less effective and may even be less effective than screening alone.