year’s recipients of Prince Mahidol’s Award in Public Health. He is receiving the award for leading the development of the world’s first effective drinkable cholera vaccine and also for transferring the technology, so the vaccine can be produced on location in developing countries. Along with this year’s runner-up, American Professor John Clemens, he has also shown that the cholera vaccine has the potential to eradicate cholera in developing countries.
“This is the world’s biggest award in the field of global health, and of course it is a great honor to be recognized in this way,” Jan Holmgren comments.
Prince Mahidol’s Award in Public Health is being awarded to Jan Holmgren and John Clemens for their ground-breaking research on the development, evaluation and introduction of effective vaccines for combating cholera. The award, which is being presented Bangkok in the presence of royalty, has been awarded to a long series of very prominent researchers since 1992.
“Several of the previous winners have subsequently been awarded the Nobel Prize for their discoveries, including for the discovery of the Helicobacter pylori gastric ulcer bacteria, the human papilloma virus that causes cervical cancer, and the rotavirus, the most common cause of diarrhea among infants. So the award is given for really extraordinary achievements in global health,” says Holmgren.
Drinkable cholera vaccine
Jan Holmgren is described as a leader in vaccine research and global health who has identified the fundamental mechanisms of disease and immunity in the case of cholera. He led the research team that developed the world’s first effective drinkable cholera vaccine and paved the way for the global availability of the vaccine by transferring technology for local vaccine production to countries where cholera causes more than three million cases of illness and 100,000 deaths each year.
John Clemens has participated in local vaccine production in developing countries, in particular the Indian Shanchol vaccine. He has led or initiated most of the many large field trials demonstrating that the cholera vaccine provides both good and long-lasting protection, and these field studies have often been carried out in collaboration with Jan Holmgren. These studies have shown that both the direct immune protection among those who received the vaccine and the indirect protection of the rest of the population has helped to reduce the spread of infection. In 2017 the World Health Organization (WHO) took note of the results and presented a global roadmap with the goal of eliminating cholera by the year 2030, mainly through extensive vaccination against cholera in vulnerable areas.
From basic research to vaccine
Cholera is an infectious intestinal disease that is caused by the Vibrio cholerae bacterium through what are called exotoxins, a toxic chemical substance that the bacteria secrete. The disease produces sudden diarrhea and vomiting that causes the sufferer to become unconscious and die, often within the space of a few hours.
Jan Holmgren laid the foundation for the development of the drinkable vaccine in 1970, when he described in detail how the toxin that causes cholera is constituted and functions. Along with Ann-Mari Svennerholm, a fellow professor at the University of Gothenburg, he showed how the intestine’s local immune defenses against cholera work and how they can be stimulated by a peroral vaccine, a vaccine that reaches the intestinal mucosa via the mouth.
Large international dissemination
During the 1980s and 1990s, Jan Holmgren, Ann-Mari Svennerholm and their colleagues developed Dukoral, which became the first effective cholera vaccine. Dukoral has since been widely disseminated internationally, and variations of the vaccine are now also produced locally in countries such as Vietnam, India, China and Korea. There is ongoing research to further improve the vaccine, including work being done by Jan Holmgren’s research team in collaboration with Indian researchers.
In the late 1980s the major field trial of the Swedish Dukoral vaccine was conducted in Bangladesh under the direction of vaccine epidemiologist John Clemens and his colleague David Sack. The study showed that the vaccine provided effective protection against cholera for several years. Since then John Clemens has worked with several large field studies in Asia and Africa that have also demonstrated the prophylactic results of locally produced peroral cholera vaccine.
Recently a cholera epidemic among nearly one million Rohingya refugees probably was averted in Bangladesh through an emergency cholera vaccination, which John Clemens initiated together with the prominent Bangladeshi vaccine researcher Firdausi Qadri and the country’s government.
Royal awards presentation
Prince Mahidol, who was the grandfather of the current King of Thailand, made great contributions to modernizing Thailand’s health and medical care. This year’s Mahidol award winners Jan Holmgren and John Clemens, along with the two leading cancer researchers who were awarded the other Mahidol award in medicine, will receive their awards in the form of a diploma, a gold medal and $50,000 each from Princess Maha Chakri Sirindihorn, President of Prince Mahidol’s Foundation, at a large awards ceremony in Bangkok on January 31, 2019.
“John Clemens has been a close personal friend and colleague for 35 years, and I am very pleased to receive this wonderful award with him. As is often the case with research awards, there are additional people who deserve to share in the prize, especially Ann-Mari Svennerholm for her important role in the development of Dukoral and Firdausi Qadri for her efforts in the evaluation and introduction of the cholera vaccine in Asia.”
TEXT: ELIN LINDSTRÖM CLAESSEN
PHOTO: MALIN ARNESSON
