The United States Health and Human Services Secretary, Tommy Thompson, last month requested that the United Kingdom biotechnology company, Acambis, speed up its development of a new smallpox vaccine amid the threat of bioterrorism attacks. Around 140,000 vials of existing vaccine are in storage at the US Centers for Disease Control and Prevention (CDC), each with doses for 50–60 people, and an additional 50–100 million doses are estimated to exist worldwide. However, this vaccine is considered unclean as it is made using cow tissue.

On 20 September, Acambis signed an exclusive $343 million deal with the CDC for initial production of a 40 million dose stockpile of the new vaccine and annual production of additional vaccine until 2020. Prior to 11 September, Acambis was scheduled to produce the vaccine for clinical trials next year, with licensing set for mid 2004, but the company is scaling up operations and aims to license the vaccine within two years.

The financial spokesperson for Acambis, David Yates, says, “The old vaccine did not meet 21st century health and safety requirements and we won a contract from the US government based on our technology. We are a relatively small company but are able to quickly scale-up operations with our subsidiary OraVax in Cambridge, Massachusetts.” OraVax will be responsible for production in live-cell cultures and pre-clinical and clinical testing of the vaccine.

The company—which is also producing a West Nile virus vaccine for the US government—will not comment on the scientific details of the deal for security reasons. However, earlier reports from the company state, “the new smallpox vaccine will be based on the same vaccinia virus strain that was licensed in the US and used for routine immunization against the disease prior to its eradication.”

Smallpox is caused by the highly infectious variola virus, and symptoms include a physically disfiguring blistering of the skin, which is deadly in 30% of cases, accompanied by pain and fever. The disease was eradicated globally in 1980 following a mass immunization campaign orchestrated by the World Health Organization (WHO), and the variola virus is now stored officially at only two research centers, the CDC and the Russian State Center for Research on Virology and Biotechnology in Koltsovo.

The WHO had advocated destruction of remaining stocks of variola virus by June 30th 1999, but fortunately, the World Health Assembly voted for a temporary retention of samples “up to and not later than 2002” for the purpose of research into antiviral agents and improved vaccines (Nature Med. 5, 474; 1999). The present climate of anthrax bioterrorism may now see that decision reconsidered.

In a January 1999 paper written for a WHO working group on orthopoxvirus infections, Donald Henderson, who directed the WHO's smallpox eradication campaign and is now at the Johns Hopkins University Center for Civilian Biodefense wrote, “The deliberate reintroduction of smallpox into the population would be an international crime of unprecedented proportions. A spreading, highly lethal epidemic in an essentially unprotected population, with limited supplies of vaccine, no therapeutic drugs, and with shortages of hospital beds suitable for patient isolation is an ominous specter.”

As few as 50–100 cases would invoke large-scale, perhaps national emergency control measures. But a September report from the US General Accounting Office called the nation's planning “insufficient,” saying that the public health infrastructure, including hospitals and emergency response teams, were not prepared to deal with the mass casualties from a terrorist act. And non-governmental medical experts told Congress at a 9 October hearing on Capitol Hill that US medical facilities and healthcare workers are largely unprepared for such an attack.