Conference on producing vaccines for developing nations

In November 2001, New Brunswick Scientific Co., Inc. (NBS) organized a two-day seminar in Nanjing City, China, to discuss new techniques for high-yield production of vaccines.

The conference brought together 60 research scientists from vaccine facilities throughout China and featured Eduardo Aycardi as keynote speaker. He is a rabies vaccine specialist who, while heading the R&D department of a government-run vaccine facility in Colombia, South America, became the first recipient of funds for a technology development project supported by the Rockefeller Foundation (www.rockfound.org) and the World Health Organization (WHO, www.who.org).

His project's goal was to develop a protocol for producing a low-cost, high-quality rabies vaccine for human and animal health care. After 12 years of designing perfusion systems, developing formulations, careful screening, yield optimization, and testing potency and dosage levels, he obtained license in 1999 for his facility to produce and sell a human rabies vaccine in Colombia. Aycardi now helps researchers in other developing nations to set up vaccine production facilities using the technology he helped to pioneer.

Aycardi told the Nanjing audience that his production methods, using VERO cells grown in an NBS 30-L sterilizable-in-place bioreactor, can produce one million doses of human rabies vaccine per year, using 25 gIL of Cytodex-- 1 (Amersham Pharmacia Biotech, www.apbiotech.com) microcarrier beads. Just three lab technicians make it happen in a 350-m2 facility under GMP conditions. Guozhong Wang, senior research scientist at the NBS cell culture laboratory, said, "Such high yields have never before been reported and are largely attributable to the NBS bioreactors patented cell-lift impeller and decanting column, which provide the high oxygen transfer, high nutrient levels, and low-shear growth environment the cells require for this level of productivity."

Aycardi's results are 10 times the average titer obtained by facilities working with roller bottle processes, the same yield as that obtained by a several-hundred-liter bioreactor system using low-- concentration beads without perfusion. Such large equipment, using large volumes of cell culture media and serum, can require more than a dozen scientists and over 1,000 m2 of facility space.

Mouse-derived vaccines require thousands of mice for vaccine production. VERO cells can be repeatedly divided and grown with each subsequent culture identical to the one that preceded it. The cells originated from African green monkey kidneys and are available from repositories such as the American Type Culture Collection (ATCC, www.atcc.org).

Rabies is rampant in many parts of the world, killing about 30,000 people a year. Aycardi's methodology might be applied to manufacturing vaccines for other life-threatening diseases including polio and Japanese encephalitis.

The Nanjing Conference was one in a series of technical programs on fermentation and cell culture techniques that NBS sponsored in 2001. For more information on upcoming education programs, cell culture product information, or technical papers, check out the company's web site at www.nbsc.com. To learn more about Aycardi's technology, contact him at eraycardi@ yahoo.com.