It has been shown in animal toxicity models that administration of Cyc
losporine, CsA, to a pregnant mouse greatly increases the risk that th
e offspring will develop autoimmunity. Immunization starting at birth
has been shown to prevent autoimmunity in other animal models of autoi
mmunity and early immunization is associated with the prevention of di
abetes in humans. Experiments were performed to see if early immunizat
ion could also prevent CsA induced autoimmunity. Mice were injected wi
th CsA during the first week of life and then immunized with killed hu
man vaccines, including common pediatric vaccines, starting in the sec
ond week of life for a total of 3-4 doses. Administration of CsA durin
g the first week of life resulted in the development of antigastric au
toantibodies which were measured at week 8 of life. Only 12% of mice t
reated with CsA alone lacked anti-agastric antibodies compared to 61%
in the group receiving the CsA and the diphtheria, tetanus, pertussis,
and anthrax vaccines (p = 0.0005). The results indicate early immuniz
ation can prevent CsA induced autoimmunity and provide further evidenc
e that the effect of starting immunization in the first month should b
e compared to starting immunization after 2 months in humans.