Acambis smallpox vaccine shows promise
Tests of U.K. company Acambis’s new smallpox vaccine show it is as effective as the old vaccine Dryvax, which is no longer being produced
Federal documents releaseed earlier this week say that an experimental smallpox vaccine works nearly as well as an older vaccine in protecting against the deadly virus, AP reports. The newer vaccine, ACAM2000, showed by separate measures that it would be nearly as effective as the older vaccine, Dryvax. ACAM2000 is derived from Dryvax, which is no longer made. Both vaccines pose similar risks of serious side effects, including itch, rash and pain as well as rare cases of inflammation of the heart and surrounding sac.
Even though ACAM2000 remains experimental, the United States already has stockpiled 192.5 million doses of the vaccine, according to its manufacturer, Cambridge, U.K.-based Acambis. Acambis anticipates its vaccine, if approved by the FDA, will be used on deployed military personnel and others at risk of smallpox if there is an outbreak.
Acambis says it is also awaiting a contract, pending approval, to maintain the ongoing capacity to make more of the vaccine (you may recall that Acambis ran into trouble in November when it failed to win a further U.S. government smallpox vaccine contract). Dryvax is currently the only U.S.-approved smallpox vaccine, but Wyeth Pharmaceuticals, of Madison, New Jersey, no longer makes it.
The United States ended routine childhood vaccination against smallpox in 1971. After 9/11, however, the Bush administration ordered some military personnel vaccinated and recommended shots for front-line health care workers. The government since has stockpiled enough smallpox vaccine for everyone in the country.
Both Dryvax and ACAM2000 are made using the vaccinia or cowpox virus, which is closely related to the smallpox virus. In 1980, world health authorities declared smallpox eradicated. The virus had been fatal in about 30 percent of cases.
