I refer to the Malaysiakini report Cervical cancer vaccination: Parents given choice.

The government is proposing a mass vaccination campaign for all 13-year-old girls to protect them against cervical cancer.

At RM400 per person, this vaccine is said to be cost-effective as compared with an estimated RM235,000 for a lifetime treatment for cervical cancer. But let’s take a closer look at the math.

The incidence of cervical cancer is about 16 out of 100,000 of the female population. Put in another way, 16 young girls out of every 100,000 will eventually contract cervical cancer later on in life.

Since the vaccine is about 70 percent effective, it is potentially beneficial to roughly 11 out of 100,000 young girls, or one girl out of a sampling of 9,090.

Here’s the catch.

Since we cannot predict which one among the 9,090 girls might eventually contract cervical cancer, we vaccinate all of them regardless of the fact that, on average, 9,089 in this sample would remain free of the disease even if left unvaccinated.

To protect that single person, the cost of vaccinating the other 9,089 who receive no benefit from the vaccine (but who might well suffer any of its unwanted side-effects) has to be factored in as well.

Therefore, preventing a single case of cervical cancer by vaccination comes with a price tag of 9,090 x 400, or RM3,636,000.

The Health Ministry says it costs RM360 million to treat 1,500 newly diagnosed cervical cancer cases every year. To prevent those 1,500 cases by vaccination, however, would cost the government almost RM5.5 billion.

I am not saying that we can put a price on the health and well-being of Malaysians. But if we decide to embark on such a programme, we need to go in with our eyes open.

Correction: I refer to my letter above.

I state that ‘16 young girls out of every 100,000 will eventually contract cervical cancer later on in life’. That statement (and hence the ensuing argument) is incorrect.

The incidence of 16 per 100,000 is the number of people who become affected with the condition each year, and not the lifetime risk that would be much higher.

I apologise for the error and any confusion it might have caused.

I have to take responsibility for my mistake. Sorry about this, but the letter was written in good faith. - Researcher , Oct 21, 2009.