Developers of influenza vaccines in Europe will have to conduct additional postmarket effectiveness studies and expand their criteria for evaluating immune responses of products in the clinical testing phase, according to the European Medicines Agency.

The requirements are part of an EMA guideline, released last week, that covers nonclinical and clinical considerations for quickly assessing the safety and efficacy of new flu vaccines. The document is the second module of an overarching guidance that will consolidate previous guidelines on the topic.

Notable changes in this module, EMA said, include new requirements for effectiveness studies of seasonal flu vaccines in the post-authorization phase, and broader criteria for evaluating immune responses beyond the use of the traditional tests for seroprotection and haemagglutination inhibition.

Because of the diversity of seasonal influenza vaccines — including egg or cell culture-derived vaccines and vaccines with and without adjuvants — product-specific effectiveness data are necessary, the guideline says. Investigations of vaccine effectiveness for individual products should be routinely performed as part of the postmarketing surveillance, it adds. The primary endpoint for testing is laboratory confirmed influenza. Secondary endpoints may include hospitalization for pneumonia and influenza, as well as for all respiratory conditions.

The guideline notes that it’s preferable to conduct the studies in the EU, but data from other regions may be acceptable if the extrapolation to the EU population can be justified.

For tests that evaluate immune response, the guideline includes suggestions of using measurements of cell-mediated immunity (i.e., the response that does not involve antibodies) in randomly selected subsets across the indented age range for the vaccine. — Neal Learner

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.