Health

May 17, 2008

Sen. Kennedy hospitalized with stroke symptoms

BOSTON (Reuters) - Sen. Edward Kennedy, was hospitalized on Saturday in Boston after suffering symptoms of a stroke at his family vacation home.

Kennedy, 76, was rushed from the Kennedy compound at Hyannisport, Massachusetts, to Cape Cod Hospital at 9 a.m. (1300 GMT), before being airlifted to Massachusetts General Hospital in Boston, hospital officials said.

A Democratic Party aide confirmed that the long-serving Massachusetts senator had stroke-like symptoms.

"He is currently under evaluation," Kennedy's office in Washington said in a statement.

Kennedy, the youngest brother of assassinated U.S. President John F. Kennedy, felt ill at home and went to Cape Cod Hospital. He was sent to Massachusetts General after consultation with his doctors in Boston.

Kennedy's family members had been summoned to Boston, The Boston Globe reported on its Web site, quoting a leading political source.

Kennedy is a leading liberal voice in the United States and has actively campaigned for Barack Obama in his bid for the Democratic presidential nomination.

"I have been in contact with the family. Obviously they're in our thoughts and prayers," Obama told reporters during a visit to a hospital in Eugene, Oregon.

He said the Kennedy family would likely release a statement about the senator's condition.

"As I've said many times before, Ted Kennedy is a giant in American political history. He's done more for the health care of others than just about anybody in history," Obama said.

"We are going to be rooting for him, and I, I insist on being optimistic about how it's going to turn out," Obama said.

Kennedy has been a vocal critic of Republican President George W. Bush, particularly on his Iraq war, tax cuts for the wealthy and conservative nominees to the U.S. Supreme Court who he fears will push the high court to the right.

But he also worked closely with Republicans on legislation including Republican presidential candidate John McCain on the controversial immigration issue.

"He is a legendary lawmaker ... When we have worked together, he has been a skillful, fair and generous partner. I consider it a great privilege to call him my friend," McCain said in a statement.

HEALTH SCARES

The white-haired senator has had other brushes with ill health. He had preventive surgery at Boston's Massachusetts General Hospital in October to unclog a partially blocked carotid artery in his neck.

The blockage was discovered during a routine check of Kennedy's back and spine, doctors said. A blocked carotid artery can lead to a stroke and death, they said at the time.

Kennedy has suffered from back problems since a plane crash in 1964 in which the pilot and one of Kennedy's aides were killed and the senator was pulled from the wreckage with a back injury, punctured lung, broken ribs and internal bleeding.

Kennedy came to the Senate in November 1962 to fill a seat earlier held by his older brother, then President John Kennedy. He currently serves as chairman of the Senate Committee on Health, Education, Labor and Pensions.

He ran for the presidency in 1980, but lost the Democratic nomination to President Jimmy Carter who was seeking a second term.

He helped win an increase in the national minimum wage this year and worked with Republicans to produce broad immigration reform, which failed in the Senate after stiff opposition from conservative Republicans.

Edward Moore Kennedy is the last of four sons and five daughters born to millionaire businessman Joseph Kennedy and his wife Rose.

The oldest, Joseph Jr, died as a World War II flier when his bomber exploded over the English Channel. John became America's first and so far only Roman Catholic president in 1960 and was assassinated in 1963. Robert's assassination during the 1968 presidential campaign left Edward leader of the clan.

(Additional reporting by Thomas Ferraro, Charles Abbott and Doina Chiacu in Washington, Jeff Mason in Eugene, Oregon. Writing by Jason Szep. Editing by Jackie Frank)

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Svea Herbst-Bayliss - Reuters | Saturday, May 17, 2008

 

May 14, 2008

Naral Pro-Choice America Backs Obama

NEW YORK (AP) - Democrat Barack Obama has won the endorsement of NARAL Pro-Choice America, a leading abortion rights advocacy organization that has supported rival Hillary Rodham Clinton throughout her political career.

The organization announced the endorsement of its political action committee on Wednesday.

"Pro-choice Americans have been fortunate to have two strong pro-choice candidates in Senator Obama and Senator Clinton, both of whom have inspired millions of new voters to participate in this historic presidential race," NARAL president Nancy Keenan said in a statement. "Today, we are proud to put our organization's grass-roots and political support behind the pro-choice candidate whom we believe will secure the Democratic nomination and advance to the general election. That candidate is Senator Obama."

Clinton communications director Howard Wolfson said he was surprised by the group's decision to back Obama.

"Senator Clinton's leadership and advocacy on choice issues is second to none," Wolfson said.

Officials said NARAL's political committee board was about evenly divided among Clinton and Obama supporters and that the decision to endorse was hard fought. Ultimately, the board voted unanimously to support the Illinois senator.

NARAL officials said the decision wasn't intended to be a snub of Clinton, who is running to be the first female president.

They said the board decided to back Obama over Clinton because he is overwhelmingly favored to win the nomination and to heal what the organization viewed as a growing rift between black voters and white female activists that the protracted Clinton-Obama contest may have caused.

The organization endorsed Massachusetts Sen. John Kerry in 2004 when he was well on the way to securing the party's presidential nomination.

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Beth Fouhy - AP | Wednesday, May 14, 2008

 

May 13, 2008

Women 'should have abortion on demand'

Women will be able to terminate their pregnancy without having to obtain the signatures of two doctors in an overhaul of abortion laws. Andrew Lansley, the shadow health secretary, told MPs on Monday he would seek to make it easier for women to have an abortion at an early stage, while lowering the time limit for late procedures.

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Rosa Prince - Daily Telegraph | Tuesday, May 13, 2008

 

April 29, 2008

Obama says rivals Clinton, McCain pandering on gas tax

Democrat Barack Obama dismissed his rivals' calls for national gas tax holiday as a political ploy that won't help struggling consumers. Hillary Rodham Clinton said his stance shows he's out of touch with the economic realities faced by ordinary citizens.

Clinton and certain Republican presidential nominee John McCain are calling for a holiday on collecting the federal gas tax "to get them through an election," Obama said at a campaign rally before more than 2,000 cheering backers a week before crucial primaries in Indiana and North Carolina. "The easiest thing in the world for a politician to do is tell you exactly what you want to hear."

Clinton, who toured the Miller Veneers wood manufacturing company in Indianapolis, said "there are a lot of people in Indiana who would really benefit from a gas tax holiday.

"That might not mean much to my opponent, but I think it means a lot to people who are struggling here, people who commute a long way to work, farmers and truckers," Clinton said. She has called for a windfall tax on oil companies to pay for a gas tax holiday.

"Senator Obama won't provide relief, while Senator McCain won't pay for it," Clinton said. "I'm the only candidate who will provide immediate relief at the pump, with a plan."

With his comments, Obama continued a running dispute over whether ending collection of the gas tax is the quickest and best way to help consumers. Leading in delegates and the popular vote, Obama in recent days has focused on McCain, but he broadened that criticism Tuesday to include Democrat Clinton.

"Now the two Washington candidates in the race have decided to do something different," said Obama. "John McCain started it, he made the proposal, and then Hillary Clinton said 'me too.'"

The plan would suspend collecting the 18.4 cent federal gas tax 24.4 cent diesel tax for the summer.

He said drying up gas tax collections would batter highway construction, costing North Carolina up to 7,000 jobs, while saving consumers little.

"We're arguing over a gimmick that would save you half a tank of gas over the course of the entire summer so that everyone in Washington can pat themselves on the back and say they did something," said Obama.

"Well, let me tell you, this isn't an idea designed to get you through the summer, it's designed to get them through an election," said Obama. He said his call for middle-class tax cuts would be far more beneficial than suspending gas tax collections.

Obama took a different view on the issue when he was an Illinois legislator, voting at least three times in favor of temporarily lifting the state's 5 percent sales tax on gasoline.

The tax holiday was finally approved during a special session in June of 2000, when Illinois motorists were furious that gas prices had just topped $2 a gallon in Chicago.

During one debate, he joked that he wanted signs on gas pumps in his district to say, "Senator Obama reduced your gasoline prices."

But the impact of the tax holiday was never clear. A government study could not determine how much of the savings was passed on to motorists. Many lawmakers said their constituents didn't seem to have benefited. They also worried the tax break was pushing the state budget out of balance.

When legislation was introduced to eliminate the tax permanently, Obama voted "no." The effort failed, and the sales tax was allowed to take effect again.

Responding to Obama's criticism, McCain campaign spokesman Tucker Bounds said the Illinois senator "does not understand the effect of gas prices on the economy. Senator Obama voted for a gas tax reduction before he opposed it."

Bounds was deliberately echoing one of Democrat John Kerry's most troublesome missteps of the 2004 presidential campaign. Kerry said of funding for the war in Iraq and Afghanistan, "I actually did vote for the $87 billion before I voted against it."

Obama returned to the gas tax theme later in the day during a rally in Hickory, N.C., conceding "the crisis families are facing is real" but suspending the gas tax wasn't the answer.

He acknowledged voting for a similar measure in the Illinois Legislature, but said he opposed efforts to extend it because "it wasn't making any difference in people's lives. It wasn't helping."

Obama and Clinton both opened their campaign day in North Carolina. Clinton toured a research facility and collected the prized endorsement of Gov. Mike Easley.

"It's time for somebody to be in the White House who understands the challenges we face in this country," said Easley, in announcing his backing of Clinton. She then promptly headed for a string of events in Indiana.

"The governor and I have something in common - we think results matter," said Clinton.

Easley is popular with white, working-class voters that have formed the base for Clinton's success in recent primaries.

Clinton also collected an endorsement from Democratic Rep. Ike Skelton of Missouri, who praised "her support in rural America, her commitment to national security and her dedication to our men and women in uniform."

Skelton, a conservative Democrat who chairs the House Armed Services Committee, was among a half-dozen Democratic House members called to meet with Clinton after she won the Pennsylvania primary last week.

While Obama is favored in North Carolina, the race in Indiana is very tight, and Obama was heading there Wednesday.

Obama collected endorsements of his own during the day: In Kentucky, Rep. Ben Chandler, son of former Gov. A.B. "Happy" Chandler, gave Obama his backing ahead of that state's May 20 primary, and in Iowa, Democratic National Committee member Richard Machacek - a supporter of former Sen. John Edwards before he dropped out of the presidential race - switched his support to Obama.

Interest in the two primaries next week has been high. Officials in Indiana said nearly 90,000 people have cast early ballots, far outpacing absentee turnout in 2004.

At stake Tuesday are 115 delegates in North Carolina, and 72 in Indiana.

---

Beth Fouhy reported from Indianapolis. Associated Press writers Christopher Wills in Springfield, Ill., and Sam Hananel in Washington contributed to this report.

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MIKE GLOVER and BETH FOUHY - AP | Tuesday, April 29, 2008

 

February 28, 2008

Obama Says He's Quit Smoking

Barack Obama said he has successfully quit smoking cigarettes despite the pressures of a closely contested and lengthy presidential campaign.

"I've been chewing on this Nicorette, which tastes like you're chewing on ground pepper - but it does help," the Democratic candidate said in an interview that aired Thursday on "The Ellen DeGeneres Show."

His wife, Michelle, had used his smoking as leverage when the two were discussing whether he should run for president. She would agree only if Obama agreed to give up smoking.

"I had been sneaking three cigarettes, four cigarettes a day for a while, and she said if you're going to do this you've got to stop - precisely because the stress was going to increase, and it'll just get worse," Obama said. "So that's an example of my wife making me a better man once again."

The Illinois senator told talk show host Ellen DeGeneres that dancing on her show had helped him win voters.

"I just want to say that we were kind of in a slump until I was dancing on the show," he joked, referring to his appearance on her show last fall. "My poll numbers skyrocketed after that. Everybody saw me bust a move on Ellen - that's all it took."

On Monday, DeGeneres showed up by satellite at a fundraiser for Hillary Rodham Clinton on the campus of George Washington University in the District of Columbia.

DeGeneres told Obama that she and many other voters find the two Democratic candidates appealing.

"I really like you. I really like Hillary. And I think a lot of people feel the same way," she said. "Why vote for you?"

Obama said he can unite the country.

"I think I have a better chance at getting Democrats and independents and Republicans to come together and put aside some partisan bickering that has been going on for a long time now that the Clintons were involved in," he said.

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Associated Press | Thursday, February 28, 2008

 

February 24, 2008

Insurance Fears Lead Many to Shun DNA Tests

The first, much-anticipated benefits of personalized medicine are being lost or diluted for many Americans who are too afraid that genetic information may be used against them to take advantage of its growing availability. In some cases, doctors say, patients who could make more informed health care decisions if they learned whether they had inherited an elevated risk of diseases like breast and colon cancer refuse to do so because of the potentially dire economic consequences.

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Amy Harmon - New York Times | Sunday, February 24, 2008

 

February 3, 2008

Clinton Health Plan May Mean Tapping Pay

Democrat Hillary Rodham Clinton said Sunday she might be willing to have workers' wages garnisheed if they refuse to buy health insurance to achieve coverage for all Americans.

The New York senator has criticized presidential rival Barack Obama for pushing a health plan that would not require universal coverage. Clinton has not always specified the enforcement measures she would embrace, but when pressed during a television interview, she said: "I think there are a number of mechanisms" that are possible, including "going after people's wages, automatic enrollment."

Clinton said such measures would apply only to workers who can afford health coverage but refuse to buy it, which puts undue pressure on hospitals and emergency rooms. Under her plan, she said, health care "will be affordable for everyone" because she would limit premium payments "to a low percent of your income."

Clinton also suggested Obama would be more susceptible to Republican attack ads in a general election because he has not been scrutinized for years as she has.

"I've been through the Republican attacks over and over again," she said on ABC's "This Week." When Obama was elected to the Senate from Illinois in 2004, she said, he "didn't face anyone who ran attack ads" comparable to those aimed at her.

Obama countered, saying Republicans and independents would be more inclined to oppose Clinton than him in a general election.

The problem is "not all of Senator Clinton's making," he said, "but I don't think there's any doubt that the Republicans consider her a polarizing figure," he said on CBS'"Face the Nation."

The presidential contenders in both parties focused their campaigning Sunday in some of the 24 states holding primaries or caucuses on Super Tuesday.

Clinton was campaigning in Missouri and Minneapolis. Obama scheduled a rally in Wilmington, Del., while some of his highest-profile surrogates - his wife, Michelle, Oprah Winfrey and Caroline Kennedy - were rallying voters in Los Angeles.

Among Republicans, Arizona Sen. John McCain was stumping in Connecticut, and former Massachusetts Gov. Mitt Romney scheduled stops in Glen Ellyn, Ill., and the St. Louis suburb of Maryland Heights. Former Arkansas Gov. Mike Huckabee was concentrating on the South, with appearances in Georgia and Tennessee.

McCain told "Fox News Sunday" he would veto any tax increase passed by a Democratic-controlled Congress. McCain, who opposed President Bush's first two tax cuts, now says Congress should make the reductions permanent, and that there also should be further tax reductions for business investments.

His chief rival, Romney, told the ABC program that McCain "doesn't understand the economy" and that his advocacy of a higher gasoline tax to combat global warming would hurt U.S. consumers.

Romney repeated his claim that McCain is outside the conservative mainstream.

"If we want a party that is indistinguishable from Hillary Clinton on an issue like illegal immigration," Romney said, "we're going to have John McCain as a nominee. That's the wrong way to go. Instead, I believe that you're going to want to have somebody who can show a contrast on issues like campaign finance reform, like illegal immigration, like global warming."

McCain, who also appeared on "Face the Nation," said he is "far more conservative" than Romney.

Huckabee said it was time for Romney, who lost major contests in South Carolina and Florida to McCain, to drop out of the race.

"I think it's time for Mitt Romney to step aside," the former governor, who has won only the Iowa caucuses, said on CNN. "If he wants to call it a two-man race, fine. But that makes it John McCain and me."

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Charles Babington - AP | Sunday, February 3, 2008

 

January 15, 2008

Drug-resistant staph found to be passed in gay sex

A drug-resistant strain of potentially deadly bacteria has moved beyond the borders of U.S. hospitals and is being transmitted among gay men during sex, researchers said on Monday.

They said methicillin-resistant Staphylococcus aureus, or MRSA, is beginning to appear outside hospitals in San Francisco, Boston, New York and Los Angeles.

Sexually active gay men in San Francisco are 13 times more likely to be infected than their heterosexual neighbors, the researchers reported in the Annals of Internal Medicine.

"Once this reaches the general population, it will be truly unstoppable," said Binh Diep, a researcher at the University of California, San Francisco who led the study. "That's why we're trying to spread the message of prevention."

According to chemical analyses, bacteria are spreading among the gay communities of San Francisco and Boston, the researchers said.

"We think that it's spread through sexual activity," Diep said.

This superbug can cause life-threatening and disfiguring infections and can often only be treated with expensive, intravenous antibiotics.

It killed about 19,000 Americans in 2005, most of them in hospitals, according to a report published in October in the Journal of the American Medical Association.

About 30 percent of all people carry ordinary staph chronically. It can be passed by touching other people or by depositing the bacteria on surfaces or objects.

The bacteria can cause deep-tissue infections if they enter the body through a wound in the skin.

Of those people who carry staph, most carry it in their noses but community-based MRSA also can live in and around the anus and is passed between sexual partners.

Incidence of MRSA is rising along with the resurgence of syphilis, rectal gonorrhea, and new HIV infections partly because of changes in beliefs about the severity of HIV and an increase in risky behaviors, such as illicit drug use and having sex that abrades the skin, Diep's team wrote.

"Your likelihood of contracting each of these diseases increases with the number of sexual partners that you have," Diep said. "The same can probably be said for MRSA."

Staph infections often look like raised red dots on the skin. Left untreated, the areas can swell and fill with pus.

The best way to avoid infection is by washing the hands or genitals with soap and water, Diep said.

(Editing by Maggie Fox and Bill Trott)

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Reuters | Tuesday, January 15, 2008

 

November 20, 2007

Stem Cell Breakthrough Everybody Could Live With

Scientists have made ordinary human skin cells take on the chameleon-like powers of embryonic stem cells, a startling breakthrough that might someday deliver the medical payoffs of embryo cloning without the controversy.

Laboratory teams on two continents report success in a pair of landmark papers released Tuesday. It's a neck-and-neck finish to a race that made headlines five months ago, when scientists announced that the feat had been accomplished in mice.

The "direct reprogramming" technique avoids the swarm of ethical, political and practical obstacles that have stymied attempts to produce human stem cells by cloning embryos.

Scientists familiar with the work said scientific questions remain and that it's still important to pursue the cloning strategy, but that the new work is a major coup.

"This work represents a tremendous scientific milestone _ the biological equivalent of the Wright Brothers' first airplane," said Dr. Robert Lanza, chief science officer of Advanced Cell Technology, which has been trying to extract stem cells from cloned human embryos.

"It's a bit like learning how to turn lead into gold," said Lanza, while cautioning that the work is far from providing medical payoffs.

"It's a huge deal," agreed Rudolf Jaenisch, a prominent stem cell scientist at the Whitehead Institute in Cambridge, Mass. "You have the proof of principle that you can do it."

There is a catch. At this point, the technique requires disrupting the DNA of the skin cells, which creates the potential for developing cancer. So it would be unacceptable for the most touted use of embryonic cells: creating transplant tissue that in theory could be used to treat diseases like diabetes, Parkinson's, and spinal cord injury.

But the DNA disruption is just a byproduct of the technique, and experts said they believe it can be avoided.

The new work is being published online by two journals, Cell and Science. The Cell paper is from a team led by Dr. Shinya Yamanaka of Kyoto University; the Science paper is from a team led by Junying Yu, working in the lab of in stem-cell pioneer James Thomson of the University of Wisconsin-Madison.

Both reported creating cells that behaved like stem cells in a series of lab tests.

Thomson, 48, made headlines in 1998 when he announced that his team had isolated human embryonic stem cells.

Yamanaka gained scientific notice in 2006 by reporting that direct reprogramming in mice had produced cells resembling embryonic stem cells, although with significant differences. In June, his group and two others announced they'd created mouse cells that were virtually indistinguishable from stem cells.

For the new work, the two men chose different cell types from a tissue supplier. Yamanaka reprogrammed skin cells from the face of an unidentified 36-year-old woman, and Thomson's team worked with foreskin cells from a newborn. Thomson, who was working his way from embryonic to fetal to adult cells, said he's still analyzing his results with adult cells.

Both labs did basically the same thing. Each used viruses to ferry four genes into the skin cells. These particular genes were known to turn other genes on and off, but just how they produced cells that mimic embryonic stem cells is a mystery.

"People didn't know it would be this easy," Thomson said. "Thousands of labs in the United States can do this, basically tomorrow."

The Wisconsin Alumni Research Foundation, which holds three patents for Thomson's work, is applying for patents involving his new research, a spokeswoman said. Two of the four genes he used were different from Yamanaka's recipe.

Scientists prize embryonic stem cells because they can turn into virtually any kind of cell in the body. The cloning approach _ which has worked so far only in mice and monkeys _ should be able to produce stem cells that genetically match the person who donates body cells for cloning.

That means tissue made from the cells should be transplantable into that person without fear of rejection. Scientists emphasize that any such payoff would be well in the future, and that the more immediate medical benefits would come from basic research in the lab.

In fact, many scientists say the cloning technique has proven too expensive and cumbersome in its current form to produce stem cells routinely for transplants.

The new work shows that the direct reprogramming technique can also produce versatile cells that are genetically matched to a person. But it avoids several problems that have bedeviled the cloning approach.

For one thing, it doesn't require a supply of unfertilized human eggs, which are hard to obtain for research and subjects the women donating them to a surgical procedure. Using eggs also raises the ethical questions of whether women should be paid for them.

In cloning, those eggs are used to make embryos from which stem cells are harvested. But that destroys the embryos, which has led to political opposition from President Bush, the Roman Catholic church and others.

Those were "show-stopping ethical problems," said Laurie Zoloth, director of Northwestern University's Center for Bioethics, Science and Society.

The new work, she said, "redefines the ethical terrain."

Richard Doerflinger, deputy director of pro-life activities for the U.S. Conference of Catholic Bishops, called the new work "a very significant breakthrough in finding morally unproblematic alternatives to cloning. ... I think this is something that would be readily acceptable to Catholics."

Another advantage of direct reprogramming is that it would qualify for federal research funding, unlike projects that seek to extract stem cells from human embryos, noted Doug Melton, co-director of the Harvard Stem Cell Institute.

Still, scientific questions remain about the cells produced by direct reprogramming, called "iPS" cells. One is how the cells compare to embryonic stem cells in their behavior and potential. Yamanaka said his work detected differences in gene activity.

If they're different, iPS cells might prove better for some scientific uses and cloned stem cells preferable for other uses. Scientists want to study the roots of genetic disease and screen potential drug treatments in their laboratories, for example.

Scottish researcher Ian Wilmut, famous for his role in cloning Dolly the sheep a decade ago, told London's Daily Telegraph that he is giving up the cloning approach to produce stem cells and plans to pursue direct reprogramming instead.

Other scientists said it's too early for the field to follow Wilmut's lead. Cloning embryos to produce stem cells remains too valuable as a research tool, Jaenisch said.

Dr. George Daley of the Harvard institute, who said his own lab has also achieved direct reprogramming of human cells, said it's not clear how long it will take to get around the cancer risk problem. Nor is it clear just how direct reprogramming works, or whether that approach mimics what happens in cloning, he noted.

So the cloning approach still has much to offer, he said.

Daley, who's president of the International Society for Stem Cell Research, said his lab is pursuing both strategies.

"We'll see, ultimately, which one works and which one is more practical."

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Associated Press | Tuesday, November 20, 2007

 

Cold virus chief suspect in AIDS vaccine failure

A cold virus used to make an experimental HIV vaccine that was discontinued in September somehow may have caused volunteers to be more susceptible to the AIDS virus, the vaccine's developers said on Wednesday.

Researchers were doubly dismayed when it appeared that those who had been vaccinated were more likely to become infected, and cautioned more than 3,000 volunteers who had been testing the vaccine that they may be at higher risk of infection.

Merck and the National Institutes of Health agree that the vaccine itself could not possibly cause HIV infection. But initial data appears to indicate that people who got vaccinated had a higher rate of HIV infection that those who got placebo shots.

Experts are hashing out the confusing findings at a meeting in Seattle. Merck and the NIH say that men with the highest pre-existing levels of immunity to a cold virus called adenovirus 5 were the most likely to have also become infected with HIV after being vaccinated.

That adenovirus was modified to use as a so-called vector or delivery mechanism in making the HIV vaccine.

Dr. Keith Gottesdiener, vice president for clinical research at Merck Research Laboratories, said it is possible an earlier infection with adenovirus 5 primed the immune system to produce more of the cells that HIV attacks.

"That is the leading hypothesis — that the vector causes production of more CD4 cells that the virus could infect," Gottesdiener said in a telephone interview.

AIDS, which has killed 25 million people globally and which currently infects 40 million, attacks immune system cells called CD4 helper T-cells. The infection itself does not kill, but it runs down the immune system so that patients die of other infections or sometimes of cancer.

Attempts to make a vaccine against HIV have flopped because of its unique effects on the immune system. The Merck vaccine was aiming to stimulate production of T-cells called CD8 killer cells, which, it was hoped, would recognize and attack HIV.

Common cold

Usually, vaccines use a whole or weakened virus to stimulate an immune response. This was too dangerous to do with HIV, so the Merck scientists used pieces of genetic material from the virus instead.

To carry them into the body, they used a virus that infects people easily — in this case, adenovirus 5, one of dozens of common cold viruses.

To test the vaccine, the researchers sought volunteers who had a high risk of HIV infection anyway, such as injecting drug users and men who have sex with men. The volunteers are counseled on ways to protect themselves, such as by using condoms, but some get infected anyway.

When they combed through the numbers, the researchers found that mostly men who had sex with other men became infected after vaccination.

They also noticed that people with more pre-existing adenovirus 5 immunity — meaning they had been infected in the past and mounted a strong immune response — were also more likely to become HIV infected after receiving the vaccine.

"Among the 778 male volunteers who had high levels of pre-existing immunity to adenovirus 5, 21 cases of HIV infection were observed in those who had received vaccine and nine cases of HIV infection were observed in the volunteers who had received placebo," Merck said in a statement.

But it was possible that people who happened to have high levels of adenovirus 5 immunity just behaved differently, having more risky sex, for instance, Gottesdiener said.

"It could be due to some biological phenomenon that we don't even understand yet or, honestly, it still could be due to chance," he said.

The trial, which began in 2004, had enrolled volunteers in the United States, Peru, Brazil, Dominican Republic, Haiti, Jamaica and Australia. A second trial had begun in South Africa earlier this year with 800 volunteers.

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Reuters | Tuesday, November 20, 2007