Killer Virus Brought Back From Past, in Hopes to Avoid a Future One
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This is SCIENCE IN THE NEWS in VOA Special English. I'm Pat Bodnar. And I'm Bob Doughty. This week on our show: A vaccine to prevent cervical cancer could be a step closer to market ...
Scientists reproduce the nineteen eighteen flu virus at a time of worry about a future outbreak of influenza ...
And, the World Bank has some money to give away for projects to help the poor.
Scientists have found similarities between the Asian bird flu known as h-five-n-one and the influenza of nineteen eighteen.
Recently, scientists recreated the so-called Spanish flu in a laboratory in the United States. They wanted to learn how the virus killed so many people. An estimated twenty million to fifty million people worldwide died of the flu. Most were under sixty-five years old.
What scientists learn about the virus could lead to new vaccines and treatments for future outbreaks of influenza.
A worldwide outbreak of disease is a pandemic. Public health officials worry that the h-five-n-one virus could cause the next flu pandemic.
The World Health Organization reported one hundred seventeen confirmed cases by October tenth. These were in Vietnam, Thailand, Cambodia and Indonesia. Sixty of the people died, forty-one of them in Vietnam.
Experts say wild birds have spread the virus as they migrate from one area to another. The current outbreak began in two thousand three. It has spread across Asia to the edge of Europe.
So far, most of the victims had been around infected birds. But the virus could mix with human flu if a person or an animal, such as a pig, gets infected with both. There is concern that the bird flu will change into a form that spreads easily from person to person. The W.H.O. says millions could die within months.
Experts say there are currently not enough supplies of anti-viral medicines and vaccines to deal with a severe outbreak.
Public health officials worry that they are in a race against time to prepare. No one can be sure when a flu pandemic will strike, or how severe it will be. A pandemic develops when people have little or no natural resistance to a new virus. The last pandemic involved the Hong Kong flu in nineteen sixty-eight. One million people died.
Influenza is normally most dangerous to the elderly and to young children. Yet many of those who died from the nineteen eighteen virus had been healthy people age fifteen to thirty-four.
The scientists who reproduced the nineteen eighteen virus say their findings confirm that it started in birds. Bird flu usually mixes with human flu before it begins to spread from person to person. However, the one in nineteen eighteen apparently defeated the body's defense system and jumped directly to humans.
A research team spent ten years studying the genetics of the virus. They used pieces of tissue from three people who died of the flu between nineteen eighteen and nineteen nineteen.
Two were American soldiers. The third was an Inuit woman whose frozen body was found in Alaska in nineteen ninety-seven.
The scientists collected enough genetic information to identify the eight genes in the virus. They used a process called reverse genetics to combine the genes and recreate the virus.
They tested the virus on chicken embryos, mice and human lung cells. Tests showed that the Spanish flu virus was much more aggressive than other flu viruses. It killed the mice and the chicken embryos. It also grew very quickly in the human lung cells.
Human flu viruses generally kill only humans. And they normally grow much slower in lung cells.
The scientists noted that the current bird flu virus has made some of the same changes as the nineteen eighteen virus did. Experts say watching for such changes may help scientists learn how to prevent a major outbreak.
The researchers also discovered that removing a gene in the remade virus weakened it. This gene could be a target for new drugs or vaccine development.
Reports about the work appeared this month in the publications Nature and Science. Scientists recreated the virus in August at the Centers for Disease Control and Prevention.
The team included researchers from the Armed Forces Institute of Pathology and the Mount Sinai School of Medicine. It also included scientists from the United States Department of Agriculture.
Some people are concerned about the public health risk of recreating such a deadly virus. But health officials argue that the risk is low. They say the knowledge to be gained outweighs the risk of accidental release or possible misuse. They say people now have some natural defenses against the virus. And they note that doctors now have anti-viral drugs that did not exist in nineteen eighteen.
You are listening to SCIENCE IN THE NEWS in VOA Special English, from Washington.
Health experts say almost three hundred thousand women die from cervical cancer each year, mostly in developing countries. The cervix is part of the female reproductive system. It is the opening at the end of the uterus.
The most common causes of cervical cancer are two forms of human papilloma virus. H.P.V. is spread through sexual activity.
The two forms linked to an estimated seventy percent of cervical cancers are called H.P.V. sixteen and H.P.V eighteen. They are responsible for growths that can lead to cervical cancer. Now, the drug company Merck is reporting highly successful results in tests of a vaccine to protect against these two forms.
Merck calls its experimental vaccine Gardasil. The results just reported came from tests with twelve thousand females in thirteen countries. They were between the ages of sixteen and twenty-six. They were not infected with H.P.V. sixteen or eighteen when they joined the study.
Half received three injections of Gardasil over six months. The other half received an inactive substance -- a placebo. The study subjects did not know which they received, the vaccine or the placebo. They were then observed for an average of seventeen months.
Merck says there were no cases of cancer linked to H.P.V. sixteen and eighteen in the group that received the vaccine. This compared to twenty-one cases in the placebo group.
The researchers say even one treatment with the vaccine provided protection. Merck reported a ninety-seven percent protection rate among women after just one injection of Gardasil.
The findings were reported in San Francisco, California, at the yearly meeting of the Infectious Diseases Society of America. The researchers did note that they are not sure how long the vaccine would provide protection.
Cervical cancer develops slowly, usually over a period of ten or twenty years. It is one of the most common cancers in women. Young, sexually active women are especially at risk of the disease.
Cervical cancer can be treated with success, especially if found early. It can also be prevented if a Pap test finds pre-cancerous conditions.
Merck says it will seek approval for Gardasil from the United States Food and Drug Administration before the end of the year. Merck says it hopes to have the product on the market sometime next year. Drug maker GlaxoSmithKline has been testing a competing vaccine for cervical cancer.
Gardasil, if approved, could be good news financially for Merck. The company faces about five thousand civil cases over its painkiller Vioxx. Merck withdrew Vioxx from sale last year. Tests showed that the drug for arthritis pain could increase the risk of heart attacks and strokes.
The World Bank is offering as much as two hundred thousand dollars for projects to improve the lives of the poor. The projects must involve creative ways to bring water, waste control or energy services to areas in developing countries. The World Bank says it has four million dollars to give away to entrepreneurs through its Development Marketplace competition.
Proposals must be made through the Internet at developmentmarketplace, all one word, dot o-r-g. The last day for proposals is November thirtieth. Winners will be announced in Washington in May.
SCIENCE IN THE NEWS was written by Caty Weaver, Jill Moss and Cynthia Kirk who was also our producer. I'm Pat Bodnar. And I'm Bob Doughty. Our programs are on the Web at voaspecialenglish.com. Join us again next week for more news about science, in Special English on the Voice of America.