HPV infection. How? When? Who?
How?
The HPV virus is transmitted essentially by sexual contact, even without penetration or ejaculation.
In theory, HPV can be transmitted via the mucous membranes and also by the cutaneous route (oral sex or touching with the hands), although it appears impossible to prove this with certainty.
When?
It is usually impossible to know when the infection was transmitted as the majority of people do not know that they have been exposed.
Who?
Likewise, it is usually not possible to know by whom the HPV infection was transmitted as it is a very common infection which can remain “dormant” for years; sex just once is sufficient to be exposed to the virus.
What is the indication for an HPV test?
There is no point in HPV testing where the individual has genital warts, diagnosed by visual inspection.
Cervical cell abnormalities caused by HPV can be detected by the cervico-vaginal smear; on the other hand, patients who have had a smear with an unclear result (ASCUS) can benefit from an HPV test which is an alternative to carrying out a further smear a few months later, or a colposcopy. Indeed, a positive HPV test is a triage method for referral for colposcopy. Other indications are very promising:
• the follow-up of women who have undergone treatment: the negative HPV test provides long-term reassurance of the absence of recurrent infection;
• primary screening after the age of 30 combined with the smear: a smear and negative HPV test enable the screening interval to be reduced perfectly safely to three years.
Will I always be an HPV carrier?
• Natural immunity gets rid of the virus spontaneously in 80% of cases, particularly in young women.
• It is difficult to predict whether the virus will be eliminated and, if it is, when.
• It is not clear whether the virus can persist at a level which cannot be detected. However, the success rate of treatments for lesions associated with HPV is very high. 90 to 98% of women with cervical lesions caused by HPV will be cured after a single treatment. The success rate of the available treatments for external condyloma acuminata is less than 70%.
How can I avoid transmitting the virus or being contaminated?
• In absolute terms, sexual abstinence would be the best means of prevention; this is an opportune moment to state that catching HPV is more or less an integral part of having a sex life.
• It is a fact that the majority of sexually-active people will be contaminated by HPV at least once during their lifetime.
• Condoms do not provide complete protection; however, they prevent numerous other viral and bacterial sexually-transmitted infections.
Can partners re-infect each other?
• The partners in a couple have a good chance of being exposed to the same HPV strain.
• Many questions remain as to the risk of being re-infected by the same HPV strain, yet no study has been carried out on re-infection or the effect of treatment on infectivity.
For cervical dysplasia caused by high-risk HPV, in practice, need for examination of the male partner should be considerably minimised due to the low viral transmissibility, the probably remote exposure to the female, and the lesser vulnerability of the male to these viral strains. This disease testifies to the woman being particularly receptive to HPV of immune origin. Condoms and the examination of the male are not worthwhile. But for genital warts, which have a high viral transmissibility, condoms and the examination of the partner are necessary.
Is HPV infection responsible for cervical cancer?
• Women are “unequal” in the face of HPV.
• So-called “high-risk” HPV is responsible for pre-cancers of the cervix, but regular screening and appropriate treatment will prevent the appearance of cancer in the majority of women.
• All women do not have the same risk.
• The main risk factor is still the persistence of the HPV virus, a sign of an individual’s immune “failure” with regard to these viruses.
• In countries where screening exists, the essential risk factor for cervical cancer is the absence of screening and not HPV infection.
What should I tell my partner about HPV infection?
• The majority of sexually-active people will be exposed to HPV.
• In the majority of cases, HPV infection is only temporary or transient.
• The majority of people will not develop symptoms, and will never know that they are, or were, exposed.
• Examination of the partner and the use of condoms are essential in the event of genital warts.
• Examination of the partner and the use of condoms are of no use in the event of cervical dysplasia.
Who can benefit from HPV vaccination?
• As far as we know today, women can benefit from the vaccination. We need to wait for the results of clinical trials currently in progress on boys to examine the expected benefit for them.
• The people most concerned by preventive HPV vaccination are young girls before the onset of sexual activity, i.e. before exposure to the papillomavirus by sexual contact. It is, however, accepted that vaccination can be offered to young women under 26 years of age who are already sexually active.
• The group aged from 9 to 26 years is that for which the European Drug Agency has granted commercial authorisation for the quadrivalent HPV 16-18-6-11 vaccine (Gardasil ®). The benefit of HPV vaccination in young girls has been demonstrated when this is part of a collective vaccination programme.
• In adult women over 26 years of age, the individual benefit of HPV vaccination is currently being evaluated. There is every reason to think that an individual benefit from vaccination is still possible for women who have not been exposed to the virus strains included in the vaccine.
In sexually active women, is it necessary to offer HPV vaccination on the basis of HPV viral status?
• To date, there are no recommendations for offering vaccination on the basis of HPV viral status in a given patient; this is particularly true for young women from 9 to 26 years of age. What has been shown is that women who have lesions due to the papillomavirus strains included in the vaccine do not obtain any therapeutic benefit from this vaccination.
• In sexually-active adult women, trials are in progress to evaluate the effect of vaccination when the virus is present in the cervical cells without producing any lesions. The preliminary data indicate that vaccination does not have any, or has only a slight, effect on women who are carriers of the HPV types contained in the vaccine but do not have any lesions, and no effect where a lesion due to HPV is present.
• The HPV vaccine is preventive and not therapeutic.
Can a pregnant woman be vaccinated?
Although no teratogenic effect (congenital abnormalities caused by a drug) has been observed in humans, this vaccination is not recommended during pregnancy.
Is it possible to give an individual vaccination to a woman over 30 years of age who so requests?
At the current time, the commercial authorisation for the HPV vaccine, Gardasil ®, has been granted for young girls from 9 to 26 years of age. Vaccinating women over 26 years old would not be covered by any recommendation. We do not currently have any clinical studies demonstrating the efficacy of vaccination after this age. However, because the vaccine is highly effective in young women, it is very probable that it can provide an individual benefit to older women who are also at risk of being exposed to the papillomavirus. In this case, it will be necessary for vaccination to be targeted at women who do not have HPV lesions and who do not have an infection at the time of vaccination. Today, we have the tools to establish the viral profile of women before vaccination.
Would it be worthwhile vaccinating a woman who has CIN lesions (dysplasia) or papillomavirus or who has already been treated for a dysplastic lesion?
• The preventive HPV vaccines available today do not have any therapeutic effect. In phase 3 trials with Gardasil ®, there is no benefit to be gained from vaccinating women who are carriers of the HPV strain contained in the vaccine.
• No studies are available about the benefit of vaccination in women who have previously been treated.
Can men be vaccinated?
At present, there are no scientific data showing the efficacy of vaccination in men and before such data are available, men should not be vaccinated.
What does the vaccination cost?
The information available today relates to Gardasil ®, launched on the market in North America, Europe and Australia. In the United States, this vaccine costs 120 US dollars per dose including medical examinations, with the three vaccinations costing 500 US dollars. In Europe, the cost of one dose of vaccine is around 130 euro. In France, following recommendations and reimbursement by the social security, a lower cost can be expected.
Will HPV vaccines be included in the vaccination programmes for children?
At present, we do not have any information to this effect. In France, the Technical Vaccination Committee (Comité Technique des Vaccinations) is currently considering this matter. Recommendations will be put forward and reimbursement for a given target population is expected in early 2007. In the United States, the institutions recommend including the HPV vaccine in child vaccination programmes. This is an important factor if broad vaccination coverage is to be achieved, a necessary condition for measuring a benefit on cervical cancer prevention in public health terms.
Do private insurers reimburse HPV vaccination?
In general, private insurance companies accept the cost of vaccinations which are included in vaccination programmes. It is very probable that this acceptance of costs will vary from one company to the next and from one policy to the next. In France, two companies have already offered this reimbursement to their clients under certain conditions.
How will the vaccination be administered? Practicalities.
• The HPV vaccine is administered by the intramuscular route, into the muscle of the upper arm or the upper thigh.
• For Gardasil ®, the programme is as follows: first injection on the set date; second injection in the second month; third injection in the sixth month.
• For Cervarix, the programme is as follows: first dose on the set date; second dose in the first month; third dose in the sixth month.
What are the side-effects of the vaccines?
The side-effects are those generally observed after vaccinations. The most frequent are fever, redness, pain, and sometimes, irritation at the injection site. More rarely, a skin rash may occur.
Is a woman permanently protected from cervical cancer when she has been vaccinated?
The answer is no. as clinical trials show that protection is only achieved against lesions caused by the papillomavirus strains included in the vaccine and not against all lesions. This represents protection of around 65% against pre-cancerous lesions and 70% against cancerous lesions. Because the protection offered by HPV vaccination will be incomplete, screening needs to be continued in accordance with recommendations and normal practice. These two synergetic and complementary preventive measures (primary with vaccination, secondary with screening) will provide maximum protection against cervical cancer.
Are boosters required?
At present, the data we have for 5 years of follow-up after vaccination show that the vaccines remain fully effective for this length of time. At 5 years, the level of antibodies produced by vaccination is still significantly very elevated compared with those after natural infection. Time will show whether boosters are necessary 8, 10 or 20 years after vaccination.