BACKGROUND: There is no information on the use of live varicella vaccine in Mexican children. Our objective was to evaluate antibody response and safety of the live varicella vaccine in both healthy and immunocompromised Mexican children. METHODS: One hundred children with no history of varicella/zoster were vaccinated with a live attenuated varicella vaccine. According to their immune status, patients were divided into either a compromised (leukemia, solid tumors, chronic renal failure, and cirrhosis) or a healthy children group. Serum IgG antibodies against VZV were measured by ELISA at baseline and at 3 and 6 months after vaccination. RESULTS: A positive VZV-ELISA at baseline was detected in 36 of 67 (53.7%) immunocompromised children and in 22 of 33 (66%) healthy children. Among VZV-seronegative children, seroconversion at 6 months post-vaccination was observed in 90.3% of compromised children and in 100% of healthy children. Increases in serum antibody levels at 3 and 6 months post-vaccination was similar in both groups. VZV vaccine-related adverse reactions, mostly mild and local, were detected in 29% of the children. Three compromised children had a mild rash symptomatic of varicella after vaccination. CONCLUSIONS: About 50% of immunosuppressed children (mean age 8.8 +/- 3.6 years) with no varicella history were VZV-seronegative. Almost all of these compromised VZV-seronegative patients seroconverted 6 months after vaccine. In addition, antibody titers were similar in both compromised and healthy children.
BACKGROUND: There is no information on the use of live varicella vaccine in Mexican children. Our objective was to evaluate antibody response and safety of the live varicella vaccine in both healthy and immunocompromised Mexican children. METHODS: One hundred children with no history of varicella/zoster were vaccinated with a live attenuated varicella vaccine. According to their immune status, patients were divided into either a compromised (leukemia, solid tumors, chronic renal failure, and cirrhosis) or a healthy children group. Serum IgG antibodies against VZV were measured by ELISA at baseline and at 3 and 6 months after vaccination. RESULTS: A positive VZV-ELISA at baseline was detected in 36 of 67 (53.7%) immunocompromised children and in 22 of 33 (66%) healthy children. Among VZV-seronegative children, seroconversion at 6 months post-vaccination was observed in 90.3% of compromised children and in 100% of healthy children. Increases in serum antibody levels at 3 and 6 months post-vaccination was similar in both groups. VZV vaccine-related adverse reactions, mostly mild and local, were detected in 29% of the children. Three compromised children had a mild rash symptomatic of varicella after vaccination. CONCLUSIONS: About 50% of immunosuppressed children (mean age 8.8 +/- 3.6 years) with no varicella history were VZV-seronegative. Almost all of these compromised VZV-seronegative patients seroconverted 6 months after vaccine. In addition, antibody titers were similar in both compromised and healthy children.