Smallpox study looks for new clues
ATLANTA (AP) – Later this month, Army virologist Peter Jahrling will put on a blue spacesuit, enter one of the country’s highest security laboratories and begin injecting monkeys with deadly smallpox. The goal is to create a way to study if new medications could battle smallpox and if new tests could detect it more rapidly, should terrorists ever resurrect the world’s scariest virus.
In one of the biggest steps yet toward modernizing defenses against smallpox, the Centers for Disease Control and Prevention this month dedicates one of its two maximum-containment laboratories to smallpox-only research like Jahrling’s indefinitely.
It is a huge step, diminishing the CDC’s capability to investigate outbreaks of highly lethal diseases such as the Ebola virus on the chance that a disease long eradicated might return – and thus a step the agency took somewhat reluctantly.
But bringing smallpox out of the deep-freeze full time speeds the race to create an arsenal of protection beyond the vaccine that is today’s only defense.
“There are tangible products with real-world applications. It’s not a lot of blue-sky, what-if research,” said Dr. James LeDuc of the CDC.
The effort is poised to begin even as vaccine experts start going around the country this week to ask Americans if the nation should change its smallpox immunization policy of giving no vaccinations unless smallpox reappears.
The smallpox vaccine itself causes serious side effects that would kill several hundred people if it were given to all Americans.
At meetings beginning Thursday in New York and San Francisco, the CDC’s vaccine advisers will hear if the public wants a different strategy, such as allowing voluntary vaccinations. On June 20 in Atlanta, the advisers then will offer the government a recommendation.
Smallpox killed hundreds of millions of people over the centuries until, thanks to massive immunizations, the last natural case occurred in 1977.
Today, live smallpox virus is confirmed as existing only in vials in heavily guarded freezers at the CDC and a similar Russian laboratory. But intelligence officials fear other countries secretly store some of the virus that could fall into terrorist hands.
Hence the research race, with Jahrling’s monkeys and other experiments.
Among them:
– CDC scientists are creating a gene-based test that might detect smallpox infection days before the characteristic rash appears, possibly allowing quarantine before the person is contagious. In test-tube studies, it seems accurate at spotting just four copies of a viral gene in blood.
– An experimental smallpox test has proved valuable in people, by diagnosing a new mutant version of the related vaccinia virus when the CDC investigated a sick worker at an outside lab last year.
This test hunts for repeated gene fragments of various viruses instead of a single gene. It would not diagnose early smallpox, but could prove crucial in pinpointing an outbreak’s source, explained CDC smallpox researcher Dr. Inger Damon.
Then there is the treatment hunt. The top candidate is cidofovir, an injected drug used by AIDS patients, both as a potential smallpox treatment and as an antidote for vaccine side effects. An experimental oral version is being studied, too.
The trick is proving any of these approaches truly works. Enter the monkeys.
Last year, Jahrling proved wrong the scientific belief that smallpox could harm only people. He injected monkeys with high doses of the same virulent strain that Russian scientists once turned into a biological weapon. Most died within a week.
People catch smallpox by breathing it. The injected monkeys got sick almost immediately, instead of a humanlike slow incubation, and the viral doses were several hundred times higher than what sickens people. One attempt at a lower dose failed.
This month, Jahrling’s research team from Fort Detrick, Md., will again try making this monkey model of smallpox more realistic with lower doses, perhaps airborne infection. Then they will test if cidofovir works. Jahrling hopes for results by Christmas.
Even if the monkey studies fail, spacesuited CDC scientists, tethered to long, red oxygen tubes, will be busy attacking thawed-out smallpox in other ways – mapping genes in the quest for a safer vaccine, hunting new drug targets.
If smallpox never reappears, will it all have been a waste?
“Oh no,” says Damon, noting smallpox is similar to the monkeypox that kills people every year, and to other viruses. “There are fundamental fascinating things to learn.”
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On the Net:
CDC smallpox information: http://www.cdc.gov
ip/smallpox/default.htm