Safety of pandemic (H1N1) 2009 monovalent vaccines in taiwan: a self-controlled case series study.

In Taiwan, new H1N1 monovalent vaccines without adjuvant and with MF59® adjuvant were used in the nationwide vaccination campaign beginning on November 1, 2009. From November 2009 through February 2010, the authors identified recipients of H1N1 vaccines who were diagnosed with adverse events of special interest (AESIs) in a large-linked safety database, and used the self-controlled case series (SCCS) method to examine the risk of each AESI in the 0-42 days after H1N1 vaccination. Of the 3.5 million doses of H1N1 vaccines administered and captured in the linked database, the SCCS analysis of Guillain-Barré syndrome (GBS) found an incidence rate ratio of 3.81 (95% confidence interval 0.43-33.85) within 0-42 days after nonadjuvanted H1N1 vaccination and no cases after MF59®-adjuvanted H1N1 vaccination. The risks of other AESIs were, in general, not increased in any of the predefined postvaccination risk periods and age groups. The databases and infrastructure created for H1N1 vaccine safety evaluation may serve as a model for safety, effectiveness and coverage studies of licensed vaccines in Taiwan.

Design of a robust infrastructure to monitor the safety of the pandemic A(H1N1) 2009 vaccination program in Taiwan.

On November 1, 2009, Taiwan began a nationwide pandemic A(H1N1) 2009 vaccine ("H1N1 vaccine") program to control the influenza pandemic. Timely assessment of immunization safety during this mass vaccination campaign was a public health priority. Therefore, the government developed a national postlicensure safety surveillance strategy to identify and evaluate new, unexpected, or prioritized adverse events in recipients of H1N1 vaccine in near real-time. We describe the design and methodology of this new safety assessment infrastructure, address challenges encountered, and its potential future use for routine vaccine pharmacovigilance in Taiwan.