- WASHINGTON "While the
government tries to ramp up production of smallpox vaccine, scientists
are hopeful that an antiviral drug that is already on the market might
prove to be the first effective treatment for the disease. Smallpox ranks
among the most serious bioterrorism threats. Unlike anthrax, the disease
is highly contagious, and, before it was eradicated, killed about one out
of three infected individuals. Survivors are left severely disfigured with
pitted scars.
-
- Health and Human Services Secretary Tommy Thompson has
said the government wants to stockpile 300 million doses of smallpox
vaccine,
enough to immunize every American if necessary. Routine smallpox
immunizations
stopped in 1972, more than 20 years after the last U.S. case was reported.
People vaccinated before then may have some residual immunity, but it's
likely not enough to prevent them from getting sick if infected.
-
- The incubation period for smallpox averages about 12
days. Infected individuals are not contagious until a day or so before
the characteristic rash appears. If a case were to be diagnosed, people
who had come in contact with the victim would be quarantined and
immunized.
-
- "We know that we have a couple of days' grace,"
says Anthony Fauci, director of the National Institute of Allergy and
Infectious
Diseases (NIAID). People can be vaccinated up to four days after coming
in contact with a contagious individual and still get protection against
smallpox, Fauci says.
-
- But all doctors have to offer smallpox patients are
therapies
to help keep them alive, not fight the virus. That's where cidofovir might
come in.
-
- Cidofovir, sold under the brand name Vistide, won Food
and Drug Administration approval in June 1996 for the treatment of
cytomegalovirus
(CMV) retinitis, a sight-threatening viral infection in AIDS patients.
It's the first product marketed by Gilead Sciences, a Foster City, Calif.,
company.
-
- In March 1998, researchers from the U.S. Army Medical
Research Institute of Infectious Diseases reported that cidofovir prevented
death and disease associated with a pox disease in primates. Monkeypox
symptoms, such as respiratory problems, fever and rash, are similar to
those of smallpox in humans.
-
- "The animal data look very striking," Fauci
says.
-
- Of course, it would be unethical to expose humans to
smallpox to test whether cidofovir was effective against that
disease.
-
- But researchers do expect to have an opportunity to test
it in a study that's just getting underway, Fauci says. The main focus
of the study is to see how effective the 15.4 million doses of smallpox
vaccine now stockpiled would be if diluted to one-fifth or even one-tenth
strength.
-
- A few of the volunteers in the study may develop a
serious
reaction to the vaccine, which contains a virus similar to smallpox.
Doctors
would first treat those volunteers with immunoglobulin containing
antibodies
to the virus in the vaccine. But if that didn't work, cidofovir would be
used as a backup, Fauci says.
- Link
-
-
-
- MainPage
http://www.rense.com
-
-
-
- This
Site Served by TheHostPros
|