Laboratory heroics

Professors Yu Yongxin of China and Sergio Henrique Ferreira of Brazil were received by Their Majesties the King and Queen in the Chakri Throne Hall of the Grand Palace last week as the winners of this year's Prince Mahidol Awards.

Yu discovered a vaccine to prevent Japanese encephalitis and Ferreira a drug that reduces deaths from congestive heart failure.

Between them they have saved millions of lives around the world.

Yu is director emeritus of the National Institute for the Control of Pharmaceutical and Biological Products.

Ferreira works in the Faculty of Medicine's Pharmacology Department at the University of Sao Paulo.

After nearly three decades of researching the best way to curb the spread of incurable Japanese encephalitis, Yu derived a vaccine called SA14-14-2 from the kidney cells of hamsters.

Following extensive tests on animals and then humans, the vaccine has come to be widely regarded as the most efficacious and safest way to prevent encephalitis in children.

Since 1988 more than 200 million children in China have been vaccinated, and millions more in India, South Korea, Sri Lanka, Nepal and Thailand.

Japanese encephalitis is one in a group of diseases caused by viruses carried by insects.

Incurable but preventable, the disease has sparked epidemics in Japan, South Korea and Taiwan but is currently under control.

Victims usually show no outward symptoms, but testing reveals inflammation of the brain and the membranes enveloping it, which can result in death or disability.

The Public Health Ministry added Yu's discovery to its list of primary vaccines as part of an Immunity Promotion Plan, and since then Japanese encephalitis has been rare in Thailand.

Ferreira discovered the Bradykinin Potentiating Factor (BPF), a peptide found in the venom of a Brazilian snake.

The revelation paved the way for the development of a new class of anti-hypertensive drugs called angiotensin-converting enzym-inhibitors.

The first to be manufactured was captopril, widely recognised for controlling hypertension, especially in diabetics with inflammatory and kidney diseases. It has greatly reduced the number of deaths from congestive heart failure.

Ferreira also discovered the mechanism by which non-steroidal anti-inflammatory drugs function, and his studies of the workings of inflammatory hyperalgesia led to the development of a selected class of highly useful analgesics.

The drugs based on Ferreira's discoveries are now among the most widely used in the relief of pain and inflammatory conditions, saving the lives of millions.