By now, you probably recognize the smallpox vaccine -- when the arm is bared for about 15 needle sticks. Wouldn't it be nice to just swallow that protection instead? Scientists are looking into that.
Two new versions of the drug, given by mouth, protected mice infected with cowpox, which is a virus similar to smallpox. Researchers say the therapy was effective when given several days before or a few days after the animals were actually infected. A second study underway finds proteins produced by the immune system, known as interferons, may also be effective as a treatment for smallpox in the form of a nasal spray.
Mice treated with interferon in a nasal spray had survival rates over 95% when infected with a smallpox like virus. But both the oral and nasal smallpox therapies must undergo more studies before they can be tested in people. The research is being presented this week at a Baltimore, Maryland biodefense symposium of the American Society for Microbiology.
The smallpox oral therapy is being studied by researchers at the University of Alabama at Birmingham, VA San Diego Healthcare System, and the University of California at San Diego. The smallpox nasal therapy is being studied by researchers at Advanced Biosystems, Inc. In Manassas, Virginia, and the Southern Research Institute in Frederick, Maryland, and George Mason University.
Over the years, smallpox has killed millions of people. Caused by the variola virus, the disease is spread from one person to another by direct contact or by infected saliva droplets carried through the air when someone coughs. Although the majority of smallpox patients recover, death occurs in 30 to 40% of cases, according to the World Health Organization.
Routine vaccination against smallpox ended in 1972 and smallpox infection was considered to be eliminated from the world in 1977. However, the level of immunity, if any, among persons who were vaccinated before 1972 is uncertain, the CDC says.
Further tests on mice receiving HDP-CDV orally once or twice a day over five days show that the animals fended off cowpox, a close relative of smallpox, reports John W. Huggins, a virologist at the U.S. Army Medical Research Institute of Infectious Diseases in Fort Detrick, Maryland.
Cowpox and smallpox spread by direct contact or via an infected host's saliva droplets that are inhaled by others. The cowpox and smallpox viruses cause skin lesions and life-threatening damage in the digestive tract and lungs. Huggins' team exposed several groups of mice to an aerosol of cowpox virus and simultaneously gave some the HDP-CDV treatment or Cidofovir. Others were untreated.