Since the chickenpox vaccine contains live but weakened chickenpox virus, the vaccine can trigger a mild case of chickenpox in about 5 percent of individuals after receiving the vaccine. A low-grade fever and rash usually does not develop until more than ten days after vaccination, and the symptoms are always mild. The rash that occurs after the vaccine usually has no more than thirty pimples throughout the body, compared to an average of 250 lesions in a typical case of chickenpox.

As previously stated, the chickenpox vaccine contains gelatin and the antibiotic neomycin. If your child is allergic to these components, she may not be eligible for the chickenpox vaccine.

Finally, there is a small but real possibility of getting shingles after receiving the chickenpox vaccine. The risk is estimated at 2 out of 100,000 doses of the chickenpox vaccine. Compared to the chance of shingles after a natural chickenpox infection, which is estimated to be 68 out of 100,000 infections, the risk of shingles after vaccination is much lower. After vaccination, shingles can appear anytime between a month and up to a few years later. Just like the “natural” shingles caused by a typical chickenpox infection, the vaccine-induced shingles is also contagious.