DEERFIELD, Ill. — Baxter International on Tuesday announced results of a study published in this week's issue of The Lancet that demonstrated effectiveness and tolerability of the company’s Preflucel in protecting against seasonal influenza.
If successfully brought to market, the new vaccine would antiquate conventional embryonated chicken egg production with a faster development cycle. That, in turn, would allow greater flexibility in identifying dominant flu strains closer to real-time and close the gap between projected supply versus actual demand. Presently, the Centers for Disease Control and Prevention helps project expected dominant flu strains for an ensuing season in the spring.
The vaccine also should help expand the market for flu shots; Preflucel is free of preservatives, antibiotics and egg proteins, and is suitable for people with egg or antibiotic allergies.
The study data showed nearly 80% protective efficacy against the influenza strains contained in the vaccine and a low adverse event profile. Preflucel is manufactured using Vero cell technology, offering an innovative method of vaccine production, compared with conventional embryonated chicken egg production, which has been used for decades.
Investigators studied the safety, immunogenicity and protective efficacy of Preflucel through a randomized, double-blind, placebo-controlled phase-3 trial, conducted in more than 7,200 healthy volunteers in the United States during the 2008-2009 influenza season.
Study results indicated that participants responded positively to the vaccine, with 78.5% protective efficacy against culture-confirmed influenza infection and robust immune responses against the three viral strains contained in the vaccine: A/H1N1- (88.0%), A/H3N2- (93.3%) and B-specific (97.1%) strains.
In addition to protection, study investigators found significantly reduced duration and severity of influenza symptoms in infected subjects in the vaccinated group, as compared with the placebo group in a subsequent analysis. The vaccine was well-tolerated, with no treatment-related serious adverse events reported during the trial.
Preflucel currently is available in Austria and Czech Republic for the 2010-2011 influenza season. Baxter expects to receive approval of Preflucel in additional countries in Europe in 2011 through a repeat mutual recognition procedure.
Preflucel clinical studies involved more than 15,000 participants, of which more than 9,000 adult and elderly participants received the vaccine. The most common undesirable effects observed were pain at the injection site, headache, fatigue, myalgia and malaise.