The studies presented at the conference show that a single shot of an experimental vaccine (a recombinant Adenovirus 35 (rAd35) vector expressing circumsporozoite protein (CSP)) protects mice against infection with the mouse malaria parasite Plasmodium yoelii. Crucell has shown in earlier studies, conducted in collaboration with Harvard Medical School, that its rAd35-based vaccines are not hampered by pre-existing adenovirus 5 (Ad5) immunity. In contrast to Ad35, antibodies to Ad5 are widespread among humans of all ages and are known to lower the immune response and thereby impair rAd5-based vaccine efficacy. Despite this, the most commonly used recombinant vaccine systems are currently based on Ad5.
Internationally renowned Dr. Moriya Tsuji from NYU commented, "We have previously demonstrated the efficacy of rAd5-based malaria vaccines in mice without pre-existing Ad5 immunity. In the present studies we found that the CSP-specific immune responses as well as the protective anti-malarial immunity were as high for rAd35 as for rAd5. However, in view of the prevalent pre-existing immunity to rAd5 among humans, these results suggest the superiority of the rAd35 vector as a potentially more effective malaria vaccine vector."
About AdVac(TM) AdVacÔ technology was developed by Crucell and is considered to play an important role in the fight against emerging and re-emerging infectious diseases, and in biodefense against viruses such as Ebola, Marburg and Lassa. Based on Crucell's PER.C6(TM) production technology, AdVac(TM) technology allows for high-yield production of replication-deficient Ad11 and Ad35 vectors and derivatives thereof. The AdVac(TM) technology is specifically designed to manage the problem of pre-existing immunity in humans against the rAd5 vaccine vector, without compromising large-scale production capabilities or the immunogenic properties of rAd5.
About Crucell Crucell N.V. is a biotechnology company dedicated to developing products that prevent and treat infectious diseases. Crucell leverages its unique PER.C6(TM) technology to develop a broad range of vaccines and antibodies. The company's development activities include collaborations with the U.S. National Institutes of Health, the U.S. Army, GlaxoSmithKline (GSK), Harvard Medical School and New York University. In addition, Crucell licenses its PER.C6(TM) technology to the biopharmaceutical industry independently and through partnerships with contract manufacturing organizations such as DSM Biologicals. Licensees include Merck & Co. Inc., for its HIV vaccine, GSK, Centocor/J&J and Aventis. Crucell is headquartered in Leiden, The Netherlands, and currently employs 180 people. Crucell is listed on Euronext and NASDAQ stock exchanges (ticker symbol CRXL). For more information visit
www.crucell.com.
