Modified smallpox vaccine tested against cervical cancer

NOTE: It is not too often that we post this type article, however with all the manufactured “fear” over smallpox and anthrax (although we believe that this one is real) scares, this seems to be one more way of urging acceptance of a mandated injection. Read, and then research – THEN – think for yourself. (Ed.)

A modified version of the smallpox vaccine is being tested as a novel weapon in the war against cancer. In early trials, the custom-tailored shot appears to boost the body’s immune system to attack the virus that is a culprit in nearly all cases of cervical cancer.

BY STIMULATING an immune response against human papillomavirus (HPV) – implicated in as many as 99 of 100 cases of cervical cancer – the vaccine is designed to prevent precancerous cellular changes from turning cancerous, Dr. Amanda Tristram of the University of Wales in Cardiff.

Early results show the strategy is working. In studies of mice, all of which were infected with two subtypes of HPV known to cause cervical cancer, none of the lab animals that were vaccinated went on to develop tumors, she said.

Even more astonishing, Tristram said, were the results of early safety studies in which 29 women with advanced cervical cancer who had failed conventional treatment with surgery and laser therapy were given the modified vaccine.

Not only did the vaccine – code-named TA-HPV – produce no side effects, but one woman who had been given months to live is still alive eight years later, Tristram said.

“Obviously one case is not proof of effectiveness, but this woman was so ill that she had already begun making arrangements for her children to be adopted after her death,” she said. “And since the other therapies had failed, one would have to conclude that the vaccine played a role in her recovery.”

And in four of 29 women treated, the body’s number of disease-fighting cells – a measure of the immune response – markedly increased, she reported. “In fact, even more women may have had a similar response,” she said, “as we didn’t have the technology to measure [immune response] then like we do now.”

~ HPV AND CANCER ~
A sexually transmitted virus, HPV infects about eight in 10 women at some point in their lives. In most cases, however, the body’s own immune system is able to fight it off and the woman experiences no signs or symptoms.

That’s where the idea for the vaccine comes in. “For those women whose HPV leads to precancerous changes that could cause cancer, the questions is, ‘Can we provoke an immune response by giving a vaccination?'” Tristram said.

There are some 100 strains of HPV, she noted, with subtypes 16 and 18 carrying the highest risk for cervical cancer. Many women infected with these strains develop precancerous cervical cells that can be detected on Pap smears, she said. Without treatment, about half of them will go on to develop full-blown cervical cancer – and 200,000 women worldwide die from the disease each year.

“Since the body’s disease-fighting soldiers are so successful at keeping most cases of HPV in check,” she said, “we developed a vaccine that acts in much the same way, recognizing the precancerous cells and attacking them.”

To create the vaccine, Tristram’s team took advantage of the fact that when HPV infects cells it produces two proteins known as E6 and E7 that cause the precancerous cells to turn deadly. Working in the lab, the team modified the proteins by “sticking them together, thus inactivating them so they could no longer cause cancer,” she explained.
Then they took DNA from the modified HPV and inserted it into the smallpox vaccine, chosen because it worked so well at producing an immune response during the 1970s eradication program.

~ THE NEW TRIALS ~
To test the approach, Tristram and colleagues plan to administer the TA-HPV vaccine to eight to 20 women with early precancerous cell changes. Their goal: to see if the vaccine can boost the immune system sufficiently to destroy the precancerous cells before having to resort to surgery or laser treatments. So far, six women in Wales have joined the study.

Using the latest molecular technology, blood and tissue samples will be examined to monitor the women’s immune response. The team will measure the immune system response not only in the bloodstream, but also in the cervix itself, where the disease actually resides.

“It’s crucial that the immune response can find its way from the bloodstream to the affected cells in the cervix, where it is needed,” said Dr. Stephen Man of the University of Wales, who is analyzing the samples. Otherwise it’s like being given a fast car, but not knowing where you’re supposed to be going.”

“This trial represents an important step from the lab to the clinic,” said Dr. Gordon McVie, director general of Britain’s Cancer Research Campaign, which funded the work. “There remains plenty of work left to do, but when Edward Jenner first developed the smallpox vaccine back in 1796, he could never have imagined that it would still have such an impact on our health over two centuries later,” he said in a statement.

If the tests prove successful, the trial will be expanded to study larger groups of women for longer periods of time. For those who worry that the modified vaccine will deplete already dwindling supplies of smallpox vaccine, Tristram points out that “it will be at least eight to 10 years before the modified vaccine will reach market.”

For now, she added, annual Pap smears, which can catch precancerous cells, remain the best protection against cervical cancer.

In addition to treating women with precancerous cell changes, her team is also developing vaccines for women with advanced disease, Tristram said.

“We’re aware that some people will be worried by what we’re doing,” said Tristram’s colleague Dr. Alison Fiander. “But we want to assure people that the smallpox vaccine and the modified version we’re using aren’t made from the smallpox virus, but from a similar, much safer virus called vaccinia.”

Additional Reference Material: Are You at Risk for Cervical Cancer?

Written by Charlene Laino for MSNBC, and published on DrKelley.info, December 27, 2001. Embedded links may no longer be active (Ed. 12.31.10)

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