In a nutshell: Facts about the Dryvax study

The proposal for the study, titled "A Multicenter, Randomized Dose Response Study of the Safety, Clinical and Immune Responses of DryVax Vaccine Administered to Children 2 to 5 Years of Age," provides the following details:

• A total of 40 children would participate in Los Angeles and Cincinnati.

• Children would be administered a purified and lyophilized product prepared from lymph obtained from the skin of vaccinia-infected calves.

• Dryvax, produced by Wyeth Laboratories, is part of a limited, 15 million-dose stockpile that was prepared 20 years ago, discontinued in 1983, and now is in storage at the Centers for Disease Control and Prevention in Atlanta.

• Two studies have been conducted with the vaccine in adults, including undiluted Dryvax and 1:5, 1:10, and 1:100 vaccine dilutions.

• Some participants experienced systemic signs and symptoms including fever, headache, muscle aches, chills, nausea, fatigue, and rashes at remote sites. More than 2% of the 665 adult subjects with vesicle formation at varying periods after vaccination rated their headaches, muscle aches, and fatigue as severe.

• Serious adverse events were experienced by 12 subjects, including one case of severe headache with nausea lasting between days five and 14 post-vaccination, and a case of erythema around the vaccination site.

• A study of children receiving the smallpox vaccine in the early 1970s focused on primary percutaneous vaccination of 786 children between the ages of 1 and 9 years. Of 148 children who received Dryvax, eight developed satellite lesions, three developed erythema multiforme; and one developed a mild illness with generalized vesicular lesions.