SARS vaccine caused liver damage in animals: lab]

[Guest guest]

>

> [Liver damage is the number one problem associated with pharmaceuticals

> - leading to all sorts of systemic problems and iatrogenic

> (physician-caused) disease]

>

> SARS vaccine caused liver damage in animals: lab

>

http://www.canada.com/national/story.html?id=c1c2e091-e92e-488c-9294-4d03e06a4d7\

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>

> Helen Branswell

> Canadian Press

>

> Sunday, November 28, 2004

>

> TORONTO (CP) - A SARS vaccine designed by Canadian scientists triggered

> severe liver inflammation when tested in ferrets - an unexpected problem

> that should give pause to others working to develop a vaccine against

> the disease.

>

> The team, which reported its findings in the Journal of Virology,

> stumbled upon the problem by accident when one of the scientists

> insisted on running unplanned blood chemistry tests on the vaccinated

> ferrets.

>

> The director of the Canadian SARS Research Network says the results are

> a red flag to all working on vaccines for the disease.

>

> " This is really important because it really is saying: proceed

> cautiously in people, " said Dr. Mark Loeb, an infectious disease

> specialist at Hamilton's McMaster University. Loeb was not involved in

> the work.

>

> The team was drawn from the Canadian Science Centre for Human and Animal

> Health, the Winnipeg complex which houses the National Microbiology

> Laboratory and the National Centre for Foreign Animal Disease.

>

> Research scientist Jingxin Cao constructed the recombinant vaccine by

> genetically modifying a pox virus to produce a protein - called the

> spike protein - which is made by the SARS coronavirus. The spike protein

> is the key protein on the SARS virus that triggers an immune response.

>

> Cao chose the modified pox virus, called MVA, because it has been widely

> - and safely - used in development of other vaccines.

>

> " It's really safe, even in the so-called immune compromised, like AIDS

> patients, " he said in an interview.

>

> The team then put the vaccine to the test, vaccinating ferrets, which

> are believed to suffer disease similar to that experienced by humans who

> contract SARS. They then waited to see whether the animals developed

> antibodies to the virus when they were exposed to SARS in what's called

> a challenge test.

>

> On that front, things went smoothly.

>

> " We had quite nice antibody levels against this protein, " said Hana

> Weingartl, head of special pathogens in the centre for foreign animal

> disease.

>

> But then colleague Markus Czub insisted on running the blood chemistry

> tests and found evidence of severe hepatitis - inflammation of the

> liver. Autopsies on the animals confirmed the finding.

>

> And there was another hitch. Their control ferrets - the unvaccinated

> animals - didn't show signs of disease, leading the team to wonder

> whether they are indeed a good model for human SARS.

>

> " They certainly do replicate the virus but they did not get sick, "

> Weingartl said.

>

> That isn't the experience of another Canadian researcher working on a

> SARS vaccine.

>

> Brett Finlay, a molecular biologist at the University of British

> Columbia, said ferrets his team tested developed symptoms similar to

> human SARS.

>

> " They got sick; they got lung disease, just like people do, " said

> Finlay, whose team worked on different kinds of vaccines, including one

> based on a killed coronavirus and another on a modified adenovirus.

>

> " You crack open the lungs and it's all inflammed and yucky, just like

> you see in SARS. "

>

> His team's results are not yet published, so they haven't been confirmed

> by outside experts through a scientific journal's peer review process.

> But he says they did not see liver inflammation - and they checked.

>

> " We did not see what they saw. We'd heard about that, so we were looking. "

>

> Finlay agreed with Loeb that all teams working on a SARS vaccine will

> have to check for liver inflammation from now on.

>

> " We'd be dumb not to, " he insisted.

>

> As for the Winnipeg team, they cannot say whether the problem they saw

> relates strictly to their vaccine or is indicative of a wider challenge

> to the development of a SARS vaccine.

>

> " We don't know whether or not this association of vaccination with

> enhanced hepatitis is only related to the MVA base, " Cao said. " Could be

> if you tried a different way - for example, adenovirus-based, another

> virus based - you won't see this. We don't know. "

>