Live attenuated varicella vaccines in patients treated with tumor necrosis factor-alpha inhibitors: A clinical trial.

BACKGROUND

Live vaccines are generally contraindicated in patients treated with biological agents. However, they are often needed in this patient population. This prospective study aimed to evaluate the immunogenicity and safety of the live attenuated varicella vaccine in patients receiving tumor necrosis factor-alpha (TNF-α) inhibitors.

METHODS

This single-center, prospective study was conducted at the National Center for Child Health and Development and registered with the Japan Registry of Clinical Trials in accordance with the Japanese Clinical Trials Act. Patients receiving TNF-α inhibitors were enrolled. Those with varicella-specific immunoglobulin G (IgG) levels <4.0 who also met predefined criteria of cellular and humoral immunity were eligible. A single dose of the varicella vaccine was administered, and varicella-specific IgG levels were measured before and after vaccination. Participants were monitored for adverse events for up to 6 months following vaccination.

RESULTS

Ten pediatric patients (five with juvenile idiopathic arthritis and 5 with inflammatory bowel disease) were enrolled. Of these, 5 achieved seroconversion (defined as a varicella-specific IgG level of 4.0 or more) after a single vaccination (seroconversion rate: 50%). Three patients received a booster vaccination, and 1 subsequently achieved seroconversion. Adverse events were nonspecific, and none were related to the varicella vaccine.

CONCLUSION

The varicella vaccine may be acceptable in patients receiving TNF-α inhibitors. However, due to the small sample size, neither the efficacy nor safety can be definitively established in this pilot study. A larger-scale study is warranted to further evaluate immunogenicity and safety.