Experts say smallpox should be kept to satisfy regulatory requirements

As the World Health Assembly’s decision looms over the remaining stocks of smallpox virus this week, independent experts say the only strong reason for keeping the virus is to satisfy strict regulatory requirements.

The experts, commissioned by the World Health Organization, recommended last December that researchers and regulatory authorities work together to find new ways to test the smallpox vaccines and antivirals so that remaining stocks of variola virus can be destroyed, CIDRAP News reports.

"(The panel) noted with concern that the only compelling scientific and public health reason to keep live variola stocks is to meet current restrictive regulatory requirements for vaccine and drug development," the report says, according to CIDRAP News. "It, therefore, recommends that researchers and regulatory authorities meet and jointly define future alternative models for testing vaccines and drugs against variola virus, in preparation for destruction of variola stocks.”

The Advisory Group of Independent Experts made its recommendation after reviewing a report by the WHO’s Advisory Committee on Variola Virus Research. The report said that there had been significant progress made in developing antivirals and vaccines from 1999 to 2010 and suggested that continued use of the variola virus in testing would permit greater confidence in their efficacy, according to CIDRAP News.

Smallpox as a disease was eradicated in the 1970s, though supplies of the virus have been kept by Russia and the United States since then. Research on antivirals and vaccines has continued out of concern terrorists might have secret supplies and use it in biological attacks.

U.S. officials introduced a resolution to retain the virus stocks at the WHA meeting on Monday.

"We're concerned that the smallpox virus may still exist outside the official repositories and could be released unintentionally or used as a bioweapon," Kathleen Sebelius, the U.S. Health and Human Services secretary said, according to CIDRAP News. "The WHO's own review of the smallpox research program concluded definitively that additional research is needed to protect public health should this occur."

The ACVVR’s review stated that while smallpox vaccines can be tested against other orthopoxviruses in animals, the smallpox virus itself would provide the best assurance of their effectiveness.

"Since smallpox has been eradicated, the efficacy of new generation vaccines will need to be tested using poxviruses related to variola virus in animal protection studies, and safety and immunogenicity studies in humans," the report says, according to CIDRAP News. "However, confidence in the ability of these vaccines to protect against smallpox would be increased by use of live variola virus for in vitro neutralization tests and non-human primate studies."