Testimony of David Satcher, M.D., PH.D., Centers for Disease Control and Prevention

additional information on high potency measles vaccine, CDC stopped all use of EZ vaccine in the
Los Angeles study in October 1991. Eight months later, in June 1992, the World Health
Organization reached a similar conclusion and recommended that high potency measles vaccines
of any strain should not be used to vaccinate children. EZ vaccine in standard doses continues to
be used around the world.
Following the termination of the EZ measles vaccine study, all children who participated in the
study were asked to enter a follow-up study to determine whether the vaccine had any adverse
health effects. Parents were informed of the reason for the follow-up study, including the fact that
some studies had found lower survival in those children who received the high potency vaccine.
Most have been medically followed and evaluated until reaching fours years of age.
To date, of all the children who have been evaluated, no child who took part in this study and
received the high potency EZ vaccine has suffered a significant health problem that can be
associated with the vaccine. CDC estimates that 95 percent of the children who were followed
up and revaccinated have serologic evidence of protection against measles. One child died
approximately 1 year after receiving a dose of standard potency EZ measles vaccine. Experts
reviewed the death certificate, the circumstances surrounding the death, and the autopsy report
and all agreed with the conclusion that the death was in all likelihood unrelated to the vaccine.
Standard potency measles vaccine has never been associated with higher mortality in any of the
vaccine studies. Recently, CDC working with Kaiser has conducted a special mortality search to

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