Attempts to quickly tackle the 2009 influenza pandemic by accelerating development timelines exposed bottlenecks in vaccine supply. The European Medicine Agency (EMA) wants to address these issues with new guidelines that emphasise the importance of responding quickly.
“Particular attention will be paid to establishing the timely availability of reliable potency assays and potential alternative assays for antigen determination especially in the frame of strain changes”, the EMA said in its guideline revision concept paper .
Regulators measure influenza vaccine potency using the single-radial immunodiffusion (SRID) assay but both the EMA and US Food and Drug Administration (FDA) want a better test. For the FDA, use of the SRID assay can slow vaccine development.
“Since timely preparation of potency reagents by regulatory authorities is challenging and always a potential bottleneck in influenza vaccine production, it is extremely important that additional approaches for reagent development be available”, researchers at the FDA said last year.
Issues with the SRID assay extend beyond timeliness. “Uncertainties in the assessment of antigen content in batches of vaccine due to variability of the currently used assay and the difficulties in its standardisation have also surfaced”, the EMA said.
The EMA has noted this problem when assessing both pandemic and inactivated trivalent seasonal influenza vaccines (TIVs). Pandemic and seasonal influenza vaccines share several other problems and the EMA will cover the clinical, non-clinical and quality aspects of both in its new guidelines.
Covering these areas in one set of guidelines will merge several documents. Current guidance documents pre-date the 2009 pandemic and were written at different times. The EMA thinks there are benefits to bringing all aspects of influenza vaccine guidance up to date in a single document.
Interested parties have until the end of the year to comment on the recommendations. After getting internal and external feedback the EMA will publish a draft of the guidelines in the first half of 2012.