Experts doubtful on HPV vaccine

Women read cervical cancer brochures at a state-run screening clinic in Latha township last year. Pic: Hein Latt Aung

CERVICAL cancer is the second most common form of cancer in Myanmar women but medical experts are divided over whether to recommend vaccination for human papilloma virus, a sexually transmitted infection that is thought to be the major cause of the disease.

The two vaccines on the market prevent at least two types of HPV that are responsible for about 70 percent of all cervical cancer, according to their manufacturers. However, some experts are concerned that women who get the vaccination mistakenly think they are protected from all forms of the virus, which is the most common sexually transmitted disease.

Dr Soe Lwin, associate professor and consultant obstetrician and gynaecologist at Yangon Central Women’s Hospital in Landamadaw township, said there were more than 100 types of HPV and the vaccines were only able to prevent virus types 16 and 18.

“These are high-risk viruses, responsible for 70pc of all cervical cancer,” he said. “But the vaccination cannot prevent 100pc of cervical cancer cases.”

He likened HPV vaccination, which has been available in Myanmar since 2005, to wearing a helmet while riding a motorcycle.

“If we have an accident while riding a motorcycle, we can’t say for sure that we won’t die even if we wear a helmet. But we are less likely to die because we are wearing a helmet,” he said. “To prevent cervical cancer vaccination is not enough; self-protection is also needed. Young people should be given sex education once they are old enough.”

Women who get the HPV vaccination should still undergo an annual pap smear test, which can detect the warning signs of impending cervical cancer.

Cervical cancer is most commonly found in women who have sex at an early age, have multiple sexual partners, have a poor immune system, use birth control pills for a long time or smoke.

Symptoms include untimely bleeding, foul-smelling blood and pus and, if the cancer cells have spread throughout the body, backaches and bleeding during urination, he said.

“Women should have knowledge of the symptoms. Cervical cancer can often be cured if discovered early but many patients come to us too late,” Dr Soe Lwin said.

While he recommends young women get the HPV vaccination, not everybody in the medical fraternity is convinced.

Dr San Yee, also an obstetrician and gynaecologist, said it needed to be made clear to women considering vaccination that it only protects against two of the 23 “high-risk” forms of HPV.

“If this is explained clearly they can consider the effect of the vaccine and whether it’s worth spending money on,” Dr San Yee said. “Every woman should take a pap smear test regularly. Many other countries operate nationwide cervical cancer screening programs. If we want to protect women from cervical cancer, a national screening program should be introduced.”

She also raised concerns about uncertainty over how long the vaccination was effective for and said the issue needed to be addressed because HPV vaccination was “becoming popular among Myanmar women”.

Another dissenting voice is Professor Thein Myint Thu, an obstetrician and gynaecologist who has conducted research into the prevalence of HPV in Myanmar women.

He said there was no solid scientific evidence that the vaccinations lowered cervical cancer rates and instead recommends a national screening program.

“If we really want to protect women from cervical cancer, a screening program should be carried out across the country,” he said, echoing Dr San Yee.

In 2009, Dr Thein Myint Thu surveyed 246 married women from low socio-economic backgrounds in Bago township, Bago Region, and Intagaw and Taukkyant townships in Yangon Region.

The privately funded survey found 20pc of the women were infected with HPV but only 2.85pc had virus type 16, and 0.4pc type 18. The most common type was 52 with a prevalence of 4pc.

A similar survey of 221 women from high socioeconomic backgrounds in Yangon found 2.2pc were infected with the high-risk type 45 HPV and 2.2pc with type 51, while type 16 was found in only 1.8pc of women and type 18 0.9pc.

Dr Thein Myint Thu plans to conduct further research on HPV infection rates in Mawlamyine in Mon State, Pathein in Ayeyarwady Region and Lashio in Shan State.

He said his findings raise questions about whether the protection the vaccine afforded was worth the relatively high cost – K100,000 for the three-dose program.

He said there were also concerns that the efficacy of the vaccine, as well as its side effects, had not been fully researched.

“Ideally the Food and Drug Administration should conduct pre-vaccination studies on national disease prevalence, efficacy and the short-term and long-term safety of vaccination in the Myanmar context before giving market authorisation for HPV vaccines,” he said. “These vaccines are available here now without being fully researched.”

The development and introduction of HPV vaccines has also been controversial worldwide. Many Western countries have introduced a free vaccination program in schools, while in Hong Kong, officials say they do not have enough data to decide whether it is beneficial to introduce a HPV vaccine widely.

Dr Thein Myint Thu said China had not yet given authorisation for the vaccines to be distributed, while in India last year the government stopped a trial following the deaths of six girls who had received the vaccine.

However, a study of 18,644 women aged between 15 and 25 years from 14 countries published in The Lancet in 2009 found one HPV vaccine, Cervarix, provided 92.9pc protection against cervical pre-cancers associated with HPV types 16 or 18.

Regardless, the World Health Organisation says “it will be years, if not decades, before we see the full benefit of vaccination in terms of a reduction in the incidence of cervical cancer”.

“Screening and treatment services will still be required because the vaccines only prevent about 70pc of cervical cancer cases,” the WHO says.

When the first vaccine became available in 2005, television station MRTV-4 launched a 30-minute program titled “Movie Stars and Cervical Cancer” with the aim of increasing awareness of the disease, including its causes and symptoms.

The program, which features actresses interviewing obstetricians and gynaecologists about the disease, also encourages parents to vaccinate their daughters as young as possible, as the vaccination is most effective between the ages of nine to 24 among women who have not yet had sexual intercourse.

The television program is sponsored by GlaxoSmithKline, the pharmaceutical company that developed Cervarix. Gardasil, a competing HPV vaccine, was developed by Merck.

A spokesperson from GlaxoSmithKline said the company sponsored the program to raise awareness about a common disease among women.

The company recommends that patients discuss with a qualified obstetrician and gynaecologist whether the vaccination is suitable for them, the spokesperson added.

Starting from July, the company started selling Cervarix at a discount in 50 countries, including Myanmar. The three-dose course costs K90,000.

“Although we have discounted the vaccine, we guarantee the quality. Our aim is to make it possible for everybody to access quality medicine,” the spokesperson said.

But Daw Thin Thin Wai, a 46-year-old mother of a teenage daughter who lives in Kamaryut township, said she had watched the MRTV-4 series on cervical cancer and found it “intimidating”.

“They say, ‘One woman dies of cervical cancer every four minutes in Asia’,” she said. “This makes women frightened and so they start taking this vaccination because they think they will get cervical cancer if they don’t.”

She added that she did not approve of girls as young as 12 or 13 participating in the discussions on cervical cancer prevention and she said she was worried the vaccine encouraged young women to be promiscuous.

“I am the mother of 15-year-old daughter. We don’t talk about sex; I’m afraid even that my daughter might have a boyfriend. I don’t think girls of this age should discuss taking the vaccination … in my opinion, if my daughter was vaccinated against cervical cancer it would be the same as if I told her that she can do whatever she likes,” she said.

“As far as I know, this cancer is sexually transmitted. If so, we should take care that our children do not to have sex before they come of age and preserve our tradition of monogamy. I think this cancer won’t occur if husbands and wives don’t commit adultery. It depends on how a person behaves in his or her life.”

A similar debate erupted in the United States following the development of Gardisil, with conservative Christian groups campaigning against a mandatory vaccination program for schoolchildren.

Dr Soe Lwin said he was not surprised people were questioning the efficacy of the vaccine but said he believed it was worthwhile if a woman could afford it.

“In the past there was no vaccination for HPV… but now women can get a vaccination with few side effects. As this cancer is very dangerous and often fatal, women should consider the pros and cons. I think they should take this vaccination if they can afford it.”