CiFlu®: A subunit vaccine for the treatment of seasonal and pandemic flu

In direct application of the impressive abilities of Ciliates, Cilian AG completed a development programme to prove the expression and efficacy of a recombinant influenza subunit vaccine candidate, internally brand named CiFlu®.

In a recent animal study, recombinant produced hemagglutinin (HA) through expression with the CIPEX-System was evaluated. Results indicated that this Tetrahymena based HA of the Influenza strain A New Caledonia/20/99 is highly immunogenic as tested in mice. For comparison, equivalent recombinant HA dosage from the same vaccine strain produced using an insect cell expression system as well as testing a monovalent vaccine from chicken eggs, induced similar or lower inhibitory immunogenicity responses.

Consequently, Cilian demonstrated in vivo efficacy of this vaccine protein. Furthermore, Cilian has achieved the expression of two other hemagglutinins. The high expression yields shown for the three different HAs, one of B strain and two of A strain influenza viruses, indicate a significant advantage over other expression systems currently used for the production of influenza vaccines. As a next step, Cilian will show the immunogenicity of these two other hemagglutinins in order to assemble a trivalent subunit vaccine composition.

Cilian is going to pursuing the development of a flu vaccine which is based on recombinant HA expressed with the innovative CIPEX system for both human and veterinary application.

The abilities of the CIPEX-System have to be considered in the context of the challenges of speed, cost effectiveness and duration of production, particularly when comparing it with the manufacturing of seasonal and pandemic flu vaccines in embryonated chicken eggs. Based on time consuming creation of reassortants and the slow production of flu vaccines in chicken eggs from start to finish, the process takes about 28 weeks. The manufacturer thus has a very short window of opportunity, which, when missed, can result in delayed supply for the population affected by the flu. This is an unsatisfactory situation in preparing vaccines for seasonal epidemic. In an all-out pandemic, egg-based production is incapable of producing large batches quickly.

The relatively long lead times in the production of flu vaccines have led to renewed demands for a quicker, more reliable method of producing vaccines than the chicken-egg method, which is a 50-year-old technology and involves injecting the virus into eggs and allowing it to proliferate.

In contrast to the common embryonated chicken eggs, Cilian anticipates to produce the recombinant subunit flu vaccine CiFlu® within 18 weeks with the CIPEX-System, which is about 10 weeks faster. Thus, with the CIPEX-System Cilian can offer to address future demand with a quicker and more reliable method of producing vaccines.

Comparison of lead times of an anticipated production of the recombinant flu vaccine CiFlu® with conventional vaccine production in embryonated chicken eggs.