The recent launch of a HPV (Human Papilloma Virus) vaccine aimed at protecting girls
and women against cervical cancer has provoked a lot of debate. Debate is good because
it is the catalyst of mass information and information is the truest form of empowerment.
Cervical
Cancer: The Facts:
Cervical cancer accounts for 1% of all cancers in the UK causing
over 1100 deaths every year. In the United States in 2002, over 12,000 women were
diagnosed with cervical cancer and nearly 4000 women died of the disease that year.
About 3700 women were expected to die of the disease in 2006.
World-wide, over 270,000
women die of cervical cancer each year and it accounts for 9% of all female cancer
deaths annually with women in the developing world bearing the brunt of this disease.
Cervical cancer is the commonest diagnosed cancer among women in Central America
and Southern Africa.
With the introduction of regular cervical cancer screening using
smears, the rate of the disease and death from it in western countries has fallen
steadily over the years. In the United States, the annual rate of fall has been around
4.5% but it is still a significant cause of morbidity and mortality among women of
all age groups.
The HPV Vaccine
The Human Papilloma Virus (HPV) infection is known
to be the leading predisposing factor to cervical changes which lead to cervical
cancer. The infection accounts for almost all cervical cancers. It is also responsible
for genital warts.
HPV is the commonest sexually transmitted infection in the United
States and quite possibly the world. Crucially it is almost always symptom-less at
the time of transmission.
There are over 100 strains or subtypes of the Human Papilloma
Virus (HPV), a third of which are sexually transmitted. The other non-sexually transmitted
strains are dubbed low-risk and possibly clinically insignificant.
The strains that
are known to predispose to cervical cancer are subtypes 16, 18, 31, 33 and a few
others.
Subtypes 16 and 18 are by far the most important accounting for 70% of cervical
cancers.
Subtypes 6 and 11 are the strains most responsible for genital warts (90%).
The
newly introduced HPV vaccine (Gardasil®) protects against subtypes 6, 11, 16 and
18. These as shown above, are responsible for the vast majority of genital warts
and cervical cancer cases. What’s more, studies have shown the vaccine to be almost
100% effective in preventing cervical cancer and other diseases, including dysplasia
(pre-cancer) of the cervix, vulva and vagina, and genital warts, caused by the four
HPV strains . That is so if given to girls and women who have not been exposed to
the virus. With that logic, it has been recommended that it be made available to
girls and young women from the age of 9 to 26 years. With universal coverage, such
a program has the potential of dramatically cutting down the rate of cervical cancer
and save millions of lives. With universal vaccination, it is estimated that such
a program could cut cervical cancer deaths by as much as 75%.
Gardasil® and Cervarix®
At the time of writing this (summer 2007), over 75 countries have approved Gardasil®
which is by the drug company Merck and Sanofi Pasteur. Another vaccine, Cervarix®
by another drug firm (GSK) protecting against HPV subtypes 16 and 18 (the strains
responsible for cervical cancer) should be approved in Europe by the end of 2007.
It is already licensed for use in Australia.
In the United States, Indiana became
the first state in January 2007 to legislate for this vaccine. The bill requires
girls to be vaccinated against HPV before the start of sixth grade. Texas followed
soon after, via an executive order in February 2007, launching the vaccination program
starting with girls entering the 6th grade in 2008. The order also makes the vaccine
available free to uninsured girls aged 9 to 18. This is an example of bold political
foresight and decision making. Other states are almost certain to follow suit.
In
Britain, it has now been agreed in principle to start vaccinating girls at the age
of 12 as from the year 2008. The vaccine is already available privately for parents
who want it for their children who may fall outside the target group such as young
teenagers at 13 -15. The cost is between £400 and 600 for a full course of three
jabs. This may be partly an acknowledgement of the fact that data show that 10% of
girls are sexually active at 14 and by the age of 16, 50% of girls are.
When to Start
Vaccinating.
While in the UK the adopted age is a reasonable and understandable compromise, it
is clear why the recommended start age is 9 years. It is to ensure girls are protected
well before they become sexually active. HPV is largely sexually transmitted and
the whole process starts there. For some, that process inexorably leads to pre-cancer
(dysplasia) changes and then cancer. This is a very distressing disease which might
eliminate the woman’s fertility, lead to premature menopause and for some, tragically,
death. The issue of age has exercised many a mind and has been one of the main areas
of contention in this debate.
There is a school of thought that argues that giving
this vaccine to such young girls is giving them a greenlight to be sexually active
without worrying about consequences. Personally, this is a track of reasoning that
I find absurd. This is similar to the mainly religious lobby which frowns upon the
availability of condoms. Only it is worse. Unfortunately, this anti-vaccine lobby
is quite powerful and voluble and sadly the most vulnerable members of our societies
are the most susceptible to this self-righteous pious posturing. Encouragingly, in
a recent study by Cancer Research UK, most (75%) mothers were in favour of having
their daughters vaccinated and 80% of them felt 10-14 years will be the appropriate
age.
Young girls grow into young women and most young women, sooner or later, become
sexually active. The sexual activity involves another individual (usually) which
means it removes the absolute control the individual might want to have about its
consequences. This is regardless of whether the sexual activity is in a religiously
acceptable context or not. It follows, therefore, that any reasonable individual
will applaud the availability of this protection for our children and young women
against one of these perennial scourges.
The HPV vaccine is a very important milestone
in our fight against cancer. I put its advent, not quite, but almost at par with
the discovery of Aspirin and Penicillin. Unsung and shrugged shoulders at launch
but now responsible for saved lives and wellbeing of billions of people across the
world over the intervening decades. It is incumbent upon those in the know to spread
the word.
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