July 5, 2009
By LIM WEY WEN
The Human Papilloma Virus (HPV) vaccine has been shown to protect against a few of the HPV virus strains that can cause cervical cancer and genital warts. But is it cost-efficient or sustainable for Malaysia?
IF GETTING immunised against all types of viruses is as easy (and as cheap) as going to a chickenpox party, then I believe most of us would have gotten immunised to many of them, intentionally or otherwise.
We would embrace our colleagues sneezing away with the virus of the season and share the bacteria on our unwashed hands, with unwavering faith that our bodies’ natural defence systems will build a long lasting reserve of ammunition to triumph over the microbial pests.
It could work, provided that the bug is benign, self-limiting and does not cause major or permanent damage.
But relying on natural exposure to pathogens to achieve immunity against them can be risky, as everyone’s immune system is different. A good example would be the common cold. It could be fatal to the very old or immunosuppressed although normal and otherwise healthy people survive.
That is why we develop vaccines to help us. With vaccines, we introduce to our immune system, weakened viruses and bacteria, or proteins that mimic parts of them. By doing so, they provide our bodies with biological face sketches of the microbes, making it easier for our immune systems to react to real bugs the next time they come around.
The Human Papillomavirus (HPV) vaccine, one of the latest vaccines (although it was approved by the US Food Drug Administration three years ago), does the same.
One protects against HPV types 16 and 18, which repeated infections are linked to cellular changes that may lead to 70% of cervical cancer cases worldwide. Another protects, on top of the previous two, against two more HPV types: 6 and 11, which is estimated to cause up to 90% of genital warts cases.
“Currently, we know that HPV infections are very common and probably almost half of all sexually active adults are infected by this virus during their lifetime,” said president of the Public Health Physician Association of Malaysia Prof Datuk Dr Syed Mohamed Aljunid.
However, according to the US Centers for Disease Control and Prevention (CDC), in 90% of cases, the body’s immune system clears the HPV infection naturally within two years. It is the remaining 10% – the infections that persist – that vaccines seek to protect us against.
But despite the aggressive marketing of HPV vaccines as a way to prevent cervical cancer, the public is slow to warm up to the vaccine.
The obvious hurdle – to individuals and also to governments that want to mass-vaccinate its people – is the price of these vaccines. To fully benefit from them, you need three injections over a course of six months (preferably before you become sexually active), and each costs about RM300.
And although they protect against the HPV types that are most likely to give you cervical cancer or genital warts, even vaccine manufacturers Merck & Co and GlaxoSmithKline agree that there is no guarantee that the vaccine will protect you against the same diseases caused by other strains of HPV or other causes. You will still need your pap smears to detect early cancerous changes although you are vaccinated.
And so, for a vaccine that is still too “young” to prove it’s long-term efficiency, the decision to recommend a national vaccination programme boils down to economics: “Will the addition of a multi-million dollar vaccination programme decrease the economic burden of treating pre-cancerous lesions and cervical cancer?”
According to a Merck Sharp & Dohme (MSD) Malaysia funded study (carried out by the Public Health Physician Association of Malaysia and Dr Sharifa Ezat Wan Puteh, senior lecturer at the UKM Medical Centre dept of community health), it can.
Researchers of the study, led by Dr Aljunid, computed the ratio of the cost needed to implement prevention strategies (Pap smear only, Pap smear and vaccination, vaccination only) for cervical cancer and the estimated number of years of life that would be added by the intervention (the quality adjusted life years or QALY). They found the Pap smear to be the most cost-effective, followed by the combined strategy and vaccination only.
“The best way is to encourage people to go for Pap smears regularly, but it is not practical … Although it has been in the market a long time, but the uptake rate is still very low,” says Dr Aljunid.
Citing socio-cultural reasons for the low uptake, such as Malaysian women’s shyness to ask for Pap smears and their reluctance to undergo the test because they have to “expose” themselves, he feels it is best to combine both Pap smears and vaccination.
Dr Sharifa sees the extra benefits in combining both the strategies.
“Although the administrative cost of the combined strategy is higher, it also has the most benefits,” she says.
“With Pap smear, you can only detect cervical cancer changes. You can’t detect vaginal cancer or genital warts, which can be prevented with vaccinations,” she adds.
Currently, the study reported, the annual cost of preventing and managing cervical cancer (which includes Pap smear screenings, treating pre-cancerous lesions and invasive cancers) in Malaysia is approximately RM250mil.
“Pap smear screening only takes up about 9% of the cost – RM22mil – while the other 91% of the cost is used to manage and treat the disease,” says Dr Sharifa, who is also one of the principal researchers of the study.
She says this figure is relatively low compared to developed countries, which devote much of their healthcare cost to screening programmes rather than cervical cancer treatment in its later stages.
The United Kingdom, for instance, spends £104.3mil (RM561.1mil) – 56.2% of their annual cost of managing cervical cancer – on Pap smear screening, and only £81.3mil (RM437.4mil) – 43.8% of the total – to treat the disease.
“This indicates that effective screening at an earlier stage reduces the economic burden of the disease,” says Dr Aljunid.
“But these are just the dollars and cents. If we don’t prevent cervical cancer, we are talking about the loss of quality of life for our patients and the loss of family members and loved ones,” he adds.