Flucelvax (Optaflu) for seasonal influenza

Abstract

Conventional egg-based manufacturing technology for seasonal influenza vaccines has several drawbacks, including its inflexibility, reliance on egg supplies, risk of contamination, absence of growth of some isolates and egg-adaptive viral mutations that threaten vaccine matching. To overcome these limitations, cell culture-derived vaccines have been designed, including the trivalent inactivated vaccine Flucelvax^®/Optaflu^® (brand names in the US/EU, respectively). Flucelvax/Optaflu has gained wide regulatory approval and is currently implemented in several countries. Non-clinical studies have assuaged hypothetical concerns regarding oncogenicity and use in persons allergic to dogs. Ample clinical data suggest the non-inferiority of Flucelvax/Optaflu to egg-based vaccines in terms of immunogenicity, safety and tolerability, and it has fulfilled American and European mandatory requirements. Although Flucelvax/Optaflu is currently indicated only for adults and the elderly, pediatric data indicate its good immunogenicity and safety. This paper provides an update on the clinical development of Flucelvax/Optaflu, its seasonal trials and available post-marketing surveillance data.

Keywords:

• Flucelvax
• influenza vaccine
• MDCK cell culture
• Optaflu
• vaccination

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• In comparison with egg-based technology, Madin–Darby canine kidney-based technology offers advantages of flexibility, a higher virus isolation rate and virus immutability, a lower risk of microbial contamination, smaller amounts of excipients and preservatives, and the possibility of being used in egg-allergic subjects.

• Flucelvax^®/Optaflu^® is the first cell culture-derived seasonal influenza vaccine to gain approval from both the EMA and the FDA by meeting the requirements for seasonal inactivated influenza vaccines imposed by both organizations.

• The Madin–Darby canine kidney 33016PF suspension cell line used to manufacture Flucelvax/Optaflu is safe: tumorigenicity, oncogenicity and hypersensitivity reactions among dog-allergic individuals are improbable.

• Across eleven Phase I-III clinical trials conducted so far, Flucelvax/Optaflu has proved safe, well-tolerated and immunogenic.

• The safety, tolerability, efficacy and immunogenicity profiles of Flucelvax/Optaflu are generally comparable to those of conventional egg-based trivalent inactivated vaccines.

• Flucelvax/Optaflu can be safely co-administered with pneumococcal vaccines in the elderly, though a slightly higher frequency of mild-to-moderate adverse reactions in comparison with egg-based inactivated vaccines has been documented.

• The robustness of the vaccine safety profile has been confirmed by a post-marketing surveillance study, which recorded no vaccine-related adverse events.

Notes