A vaccine could cut tuberculosis cases among HIV-positive Africans by almost two-fifths, a US study suggests.

The lung infection is the most common cause of death among HIV patients in the continent.

Journal Aids reports that Dartmouth Medical School research involving 2,000 people found significantly fewer TB cases in vaccinated patients.

An expert said the jab could be a cheaper option for countries struggling to find money for extra anti-HIV drugs.

HIV patients are particularly vulnerable to TB because their immune systems are compromised.

The vaccine works by boosting the immune responses of patients who have already been given the BCG vaccine earlier in life.

In itself, the BCG jab may offer some protection against TB, but this is far from certain, and protection may only last a few years after immunisation.

The researchers from Dartmouth Medical School in the US tested it among 2,000 HIV positive patients in Tanzania over a seven-year period.

The number of confirmed TB cases was 39% lower in the vaccinated group.

First vaccine

Professor Ford von Reyn, who led the study, said it was a “significant milestone”.

One theory now suggests that patients could be given the booster jab as soon as they are diagnosed with HIV, before antiretroviral drugs are needed.

Alvaro Bermejo, executive director at the International HIV/Aids Alliance, said that the other way of fighting TB in HIV patients might be to give them antiretrovirals earlier, an expensive option compared with a vaccination programme.

He said: “This is a very important finding – it is the first time we are going to have a vaccine which is influential in preventing opportunistic infections in HIV patients.

“TB is a massive problem – a third of people living with HIV in Africa are infected with it.

“The reduction of 39% seen in Tanzania, although not fabulous, is a good result.”

University of Missouri researchers have found evidence that some over-the-counter drugs

“If you’re taking aspirin regularly, which many people do for cardiovascular treatment, or acetaminophen (Tylenol) for pain and fever and get a flu shot,there is a good chance that you won’t have a good antibody response,” said Charles Brown, associate professor of veterinary pathobiologyin the MU College of Veterinary Medicine. “These drugs block the enzyme COX-1, which works in tissues throughout the body. We have found that if you block COX-1, you might be decreasing the amount of antibodies your body is producing, and you need high amounts of antibodies to be protected.”

COX enzymes play important roles in the regulation of the immune system. The role of these enzymes is not yet understood completely, and medications that inhibit them may have adverse side effects. Recent research has discovered that drugs that inhibit COX enzymes, such as COX-2, have an impact on the effectiveness of vaccines. Brown’s research indicates that inhibiting COX-1, which is present in tissues throughout the body, such as the brain or kidneys, could also impact vaccines’ effectiveness.

These MU researchers also are studying the regulation of inflammation and how that leads to the development or prevention of disease. Many diseases, such as arthritis, cardiovascular disease and diabetes, are all chronic inflammatory diseases. Contrary to previous beliefs, inflammation is generally a good thing that helps protect individuals from infection. Many of the non-steroidal drugs that treat inflammatory conditions reduce antibody responses, which are necessary for treating infections.

“So far, we’ve tested this on an animal model and have found that these non-steroidal drugs do inhibit vaccines, but the next step is to test it on humans,” Brown said. “If our results show that COX-1 inhibitors affect vaccines, the takeaway might be to not take drugs, such as aspirin, Tylenol and ibuprofen, for a couple weeks before and after you get a vaccine.”

But the Opinion Research Corporation survey, released Tuesday morning, indicates a small majority continue to say that the government and private industry eventually will produce enough of the vaccine for the virus, also known as swine flu, to inoculate everyone who wants it.

According to the poll, 51 percent of those questioned are confident in the government’s ability to prevent an H1N1 epidemic, with 49 percent not confident. The number of Americans who are confident is down 8 percentage points from August, while the number of those not confident is up 9 percentage points.

“Only one in 10 say they are ‘very confident’ that the government can ward off an epidemic,” says CNN Polling Director Keating Holland. “But the growing doubts may not be directly related to the shortfall of vaccine so far.”

Fifty-three percent of those questioned say that government and private industry can produce enough vaccine for everyone who wants a swine flue shot. That number is essentially unchanged since August.

The poll indicates that one group in particular is skeptical about the government’s efforts to battle swine flu.

“Only 43 percent of mothers with children under the age of 18 are confident in the government’s ability to prevent an epidemic,” says Holland. “That’s 7 points lower than fathers and 10 points lower than people who don’t have young children. Mothers are also most likely to think that there will not be enough vaccine to go around.”

According to the poll, 57 percent approve of how President Obama’s handling the government’s response to H1N1, with 4 in 10 saying they disapprove.

The CNN/Opinion Research Corporation poll was conducted October 30 through November 1, with 1,018 adult Americans questioned by telephone. The survey’s sampling error is plus or minus 3 percentage points for the overall sample.

Federal health officials report that the swine flu remains widespread in 48 states but add that the supply of vaccine has reached 32 million doses, double what was available two weeks ago.

Sources: cnn.com

A vaccine to treat cocaine use helps some addicts to halve their dependency on the drug, researchers say.

Doctors at Yale University School of Medicine gave the vaccine to 55 cocaine addicts and found that 38% were able to achieve the necessary antibody levels.

Animal and human studies have suggested that high levels of anti-cocaine antibodies in the blood can stop addicts experiencing a high.

But the researchers say the addicts would need repeat injections.

The study published in the journal of the American Medical Association says the Yale doctors conducted a 24 week trial of an experimental vaccine.

Randomly assigned

A total of 115 cocaine and opiate-dependent individuals were enrolled and randomly assigned to receive five vaccinations of the active vaccine or five vaccinations of a dummy treatment over 12 weeks.

They don’t destroy, they neutralize the cocaine and make it vulnerable to a cholinesterase enzyme which will then break it down Dr Thomas Korsten, Baylor College of Medicine

Cocaine is flushed out the body in about three days so the doctors tested all the addicts urine for metabolised cocaine three times a week for 24 weeks.

Of the 55 people who completed the course 21 (38%) attained antibody levels of 43 micrograms per millilitre or higher.

Those with that level of antibodies had significantly more cocaine-free urine samples (45%) between week nine and 16 of the study than individuals who had lower antibodies (35%) and those who received dummy treatments.

Cocaine use halved

The proportion of participants who reduced their cocaine use by half was significantly greater among those treated with the active vaccine – 53% compared to 23% in the placebo group.

The researchers said about 40% of the participants achieved antibody levels of 20 micrograms per millilitre.

They said this was enough to combat one to two doses of cocaine which should be enough to prevent relapses in many patients.

Dr Thomas Korsten, of Baylor College of Medicine who started the study while he was at Yale, said: “While these antibodies are in the blood targeting cocaine – the drug does not have an effect.

“They don’t destroy, they neutralize the cocaine and make it vulnerable to a cholinesterase enzyme which will then break it down.

“The vaccine binds the cocaine so that it can’t effect the brain, the heart or any other organ.

“This is the first successful placebo controlled test of a vaccine for cocaine.”

Two years of treatment

The adverse events associated with the vaccine were mild to moderate with the most frequent complaint being hardening and tenderness at the injection site.

Dr Korsten said: “We think most people will need two years of treatment with the vaccine – bearing in mind there is an average six to eight years of abuse before they come for treatment.

“It’s only at week eight that we get full levels of blocking antibodies.

“We have already tried the vaccine with a different carrier supplied by Merck Pharmaceuticals – this is based on the meningitis virus and it is provoking much better levels of antibodies.

“We are excited because of all the other drugs we can design antibody vaccines for.

“All the other drugs of addiction should work except alcohol because that molecule is too small to make an antibody to it.”

They used new technology to troll through the blood of 1,800 people infected with the AIDS virus and identified two immune system compounds called antibodies that could neutralize the virus.

And they found a new part of the virus that the antibodies attack, offering a new way to design a vaccine, they reported in the journal Science.

“So now we may have a better chance of designing a vaccine that will elicit such broadly neutralizing antibodies, which we think are key to successful vaccine development,” said Dennis Burton of The Scripps Research Institute in La Jolla, California, who led the study.

“The findings themselves are an exciting advance toward the goal of an effective AIDS vaccine because now we’ve got a new, potentially better target on HIV to focus our efforts for vaccine design,” added Wayne Koff of the International AIDS Vaccine Initiative, or IAVI, which sponsored the study.

Since the AIDS pandemic started in the early 1980s, more than 25 million people globally have died from the virus. The World Health Organization estimates that 33 million are currently infected.

There is no cure, although a cocktail of drugs can help keep the virus under control. Efforts to make a vaccine have failed almost completely.

MUTABLE VIRUS

Part of this is because the virus mutates so much that any one person is infected with millions of different versions, each one appearing different to the immune system.

In addition, the virus infects the very immune cells that are supposed to help protect the body. And if even one virus gets past the immune defense, it appears to set up a lifelong infection. No drug has been able to eradicate it.

IAVI director Dr. Seth Berkley said the findings will not lead directly to a vaccine, but show that there are new and better ways to design one.

He said 10 percent of the patients whose blood was screened had a strong antibody response to the virus. “We have people with even more potent serum out there. We will probably see more,” he said in a telephone interview.

It may also be possible to use such antibodies as therapy themselves — such as the gamma globulin used for hepatitis virus. But the eventual goal, Berkley said, is a vaccine that produces antibodies that could stop the virus from ever infecting a person in the first place.

“We haven’t been able to do that because we haven’t been able to find the right kind of response,” Berkley said.

Most vaccines elicit an antibody response, priming the body to make antibodies that will recognize and attack an invader such as a bacteria or virus.

The two antibodies, called PG9 and PG16, are the first new HIV antibodies to have been identified in more than 10 years. They target a region of the spike the virus uses to infect cells, the researchers wrote.

A team at South San Francisco-based Monogram Biosciences Inc screened the blood for the ability to neutralize HIV. Theraclone Sciences used its technology to identify the antibodies involved.

North Carolina-based Laboratory Corp of America Holdings acquired Monogram in July.

(Editing by Eric Walsh)

http://www.reuters.com/article/healthNews

In the Canadian version of the vaccine, Health Canada has chosen to include an adjuvant. It is a substance that will increase the immunological response to antigens. As a result, this will slow its use but allow more people to be immunized. The use of an adjuvant requires a more careful review compared to a vaccine without an adjuvant.

Dr. Paul Hebert, Editor-in-Chief and Dr. Noni Macdonald, Senior Editor, Public Health at CMAJ recommend providing the vaccine without adjuvant to high-risk groups to facilitate quick vaccination. The US and Europe will follow this similar approach. The rest of the population can comply with the slower method with an adjuvant vaccine.

“Time is running out,” they write. “Only by providing fast-track standard vaccine can high-risk groups be protected in a timely way, while the general public awaits the arrival of the adjuvant vaccine.”

Written by Stephanie Brunner (B.A.)
Copyright: Medical News Today