The World Health Organisation (WHO) has announced that eight vaccine candidates for COVID-19 have entered human trials.
- In a human challenge trial, participants are deliberately exposed to the infection (in this case it is SARS-CoV-2 virus), in order to study the disease and test the vaccines.
- For this, the exact virus strain that will be used to infect the participant and dosage or how much of the virus the volunteers need to be exposed to needs to be determined and approved by the regulatory authorities.
- Human challenge trial isn't new. The method has been used for developing vaccines for seasonal flu, typhoid, malaria, and cholera, among others.