The
current measles vaccine used in the United States is prepared
from the Moraten strain, an attenuated strain developed from
the Edmonston B strain of measles virus through multiple
passages in chicken embryo cells (47). Figure 3 shows the
various vaccines used over a time line from 1963 to 1989.
Figure 4 diagrams the derivations of the various measles vac-
cines that have been or are in use. The Moraten strain pro-
duces fewer side effects than does the original vaccine derived
from the Edmonston B strain. According to studies performed
in the 1970s, it is not sufficiently immunogenic in children
under 9 months of age; however, as discussed above, those
studies may not apply to children born in the 1990s (68, 69).
Several studies have demonstrated that the Edmonston- Zagreb (E-Z) vaccine administered to children at 4 to 6
months of age induces seroconversion rates equal to or greater
than those achieved by a standard dose of Schwartz or
Moraten vaccines administered at 9 months of age (55, 60).
The reasons for the increased immunogenicity of the Edmon-
ston-Zagreb vaccine is not known. In addition, a Schwartz
vaccine with increased potency has been tested for infants at 4
to 6 months of age and has been shown to be effective (1, 40,
55, 60).
Тема: 
Сообщение от Фэй
Ответить с цитированием
Социальные закладки