Body's anti-HIV 'training manual' offers vaccine hopes

The body's own "training manual" for successfully attacking HIV has been recorded by scientists and it is hoped it can be used to design vaccines.

HIV mutates to survive the onslaught of a patient's immune system.

However, some patients develop highly effective antibodies that can neutralise huge swathes of HIV mutants.

An analysis of the arms race between body and virus, published in the journal Nature, has shown how these antibodies are made.

When someone is infected with HIV, their body produces antibodies to attack it. But the virus mutates and evades the offensive, so the body produces new antibodies that the virus then evades and the war goes on.

However, after about four years of this struggle some patients hit on to a winner by targeting something the virus finds harder to change - an Achilles heel.

Barton Haynes

"Even though the virus mutates and there are literally millions of quasi-species of virus because of all these mutations, but there are parts the virus can't change otherwise the virus cannot infect - these are the vulnerable sites," Prof Barton Haynes, of Duke University, in North Carolina, reported.

At this stage of the infection it is far too late to make a difference for the patient as the virus is hiding in untouchable reservoirs.

However, some researchers believe that vaccines that encourage the body to produce these "broadly neutralising antibodies" may give people immunity to the virus.

The research team's study is based on a patient in Africa who had a rapid diagnosis, about four weeks after being infected with the virus.

They were eventually able to produce an antibody named CH103 that could neutralise 55% of HIV samples.

It was not produced in one easy step. Rather it was the product of the war of the immune system and HIV trying to out-evolve each other.

However, through regular genetic analyses of both the immune system and virus, researchers could piece together each of the steps that culminated in the production of CH103.

It is like a training manual for the immune system.

Prof Haynes said: "What we were able to do was map out the arms race of both virus and antibody, and in doing so we have now a map.

"This is the first time we've been able to see the actual road map."

He said the challenge now was to see if re-creating those steps could lead to a viable vaccine.

Jane Anderson

However, he said it would almost certainly need to be a vaccine combining multiple "Achilles heels" - in the same way that HIV therapies are a combination of drug treatments.

Prof Jane Anderson, consultant at Homerton hospital in London and chair of the British HIV Association, said: "The study gives important insights into the ways in which the human immune system responds to HIV infection and increases our understanding about the relationships between the virus and the human host.

"This is another welcome step on the path to develop vaccines against HIV."

Sarah Joseph

Dr Sarah Joseph, who tests HIV vaccines at the Medical Research Council clinical trials unit, said: "This paper is really interesting. Some people do make antibodies that neutralise a lot of HIV virus, bit it is not of use to them as they produce it way too late."

She said harnessing these antibodies "could be a big deal" and there was "even talk about mass-producing antibodies and infusing people with them".

H1N1: Swine Flu Mutations endangers Europe: WHO issues ineffective rhetoric

Swine flu virus mutations are spreading in Europe, French health officials said Friday as the World Health Organisation reported a leap in deaths from the disease by more than 1,000 in a week.

Two patients who were infected by a mutation that was also recently detected in Norway have died in France, the government's Health Surveillance Institute (InVS) said in a statement.

"This mutation could increase the ability of the virus to affect the respiratory tracts and, in particular, the lung tissue," said a statement from "For one of these patients, this mutation was accompanied by another mutation known to confer resistance to oseltamivir," it added, referring to the main drug being used to treat swine flu, under the brand name Tamiflu.

The case was the first drug-resistant strain found in France among the 1,200 strains experts have analysed here, the InVS said, adding that "the effectiveness of vaccines currently available is not being questioned."

The two patients were not related and had been hospitalised in two different cities in France, it said.

The WHO said Friday the death toll had reached at least 7,826 worldwide since the A(H1N1) flu virus was first uncovered in April.

The number of deaths reported to the UN health agency showed the biggest rise in the Americas, where 5,360 deaths have now been recorded compared to 4,806 a week ago.

But Europe also posted a substantial increase percentage-wise with at least 650 fatalities now reported, representing a surge of 300 deaths or 85 percent from data posted a week ago.

The WHO said Thursday it was investigating reports of mutations in the virus, after half a dozen countries recorded such cases.

"The question is whether these mutations again suggest that there is a fundamental change going on in viruses out there -- whether there's a turn for the worse in terms of severity," said Keiji Fukuda, WHO's special adviser on pandemic influenza.

"The answer right now is that we are not sure," he added following reports from China, Japan, Norway, Ukraine and the United States.

He noted, however, that mutations are common in influenza viruses, and "if every mutation is reported out there it would be like reporting changes in the weather."

"What we're trying to do when we see reports of mutations is to identify if these mutations are leading to any kinds of changes in the clinical picture -- do they cause more severe or less severe disease?

"Also we're trying to see if these viruses are increasing out there as that would suggest a change in epidemiology," he added.

China said earlier Thursday that it had discovered eight people with mutated versions of swine flu while Norway reported last week that it had detected one case.

Fukuda also said that the UN health agency was looking into Tamiflu-resistant cases reported in Britain and the United States but noted they concerned people who are already undergoing treatment for other diseases or who have underlying health issues.

The health agency was therefore maintaining its assessment that Tamiflu, produced by Swiss drugmaker Roche, remained "effective" as a treatment for swine flu, but that "we do have to be vigilant in these very susceptible people."