What adverse events are associated with varicella-containing vaccines?
Varicella-containing vaccines are very safe. In uncontrolled trials, vaccine recipients reported minor injection site complaints (20% reported pain, swelling or redness) and rashes (3%-5% reported a localized rash, and an additional 3%-5% developed a generalized varicella-like rash 5-26 days after vaccination). However, the rate of adverse events was much lower in the only randomized, controlled clinical trial conducted in children. In this trial, 1% of vaccine recipients developed injection site rash compared with 0.3% of placebo recipients, and 3.2% of vaccine recipients developed generalized rash compared with 1.7% of placebo recipients. These rashes had an average of 2-5 lesions and were likely to be maculopapular rather than vesicular. The incidence of fever did not differ between the vaccination and placebo groups. The safety profile for the two-dose regimen was comparable to that of the one-dose regimen. Injection site complaints were slightly higher after dose two (25% versus 2
