Controlled human infection model trials (CHIMs), in which volunteers are deliberately exposed to pathogens under closely monitored conditions, continue to gain ground in Europe, but Japan is taking a more guarded stance.
Researchers say CHIMs can speed up the development of vaccines and treatments by involving fewer participants and shorter study periods than traditional clinical trials. In Belgium, for instance, some facilities run studies with only 20 to 200 subjects over several months, compared to conventional trials that may require 1,000 to 40,000 participants and take years to complete.
Japan, however, remains hesitant due to ethical and safety concerns, underscored by sensitivity to issues surrounding human experimentation. A government plan released earlier this year flagged potential ethical risks and emphasized that adopting CHIMs would require extreme caution.
European countries, including the United Kingdom, Germany and the Netherlands, have already adopted CHIMs for infectious diseases with low mortality risks. Japan’s health ministry maintains that any move toward similar trials must not be rushed.
As governments aim to strengthen preparedness for future pandemics, the differing positions reflect the balance between accelerating scientific innovation and ensuring volunteer safety. (PNA)