<span style="color: #222222;">Chief Scientist in World Health Organization Dr. Soumya Swaminathan has said that 24 vaccine candidates are in the human clinical trial stage and 150 vaccines are in the pre-clinical stages worldwide. She said, WHO has robust pipeline of potential COVID vaccine candidates and the more vaccine candidates will maximise the opportunities.</span><br />'' <b><span style="color: #222222;"> </span></b><br />'' <span style="color: #222222;">Dr Swaminathan said, three vaccine candidates are in the Phase-3 trial stage which are Oxford vaccine developed by Astrazeneca, mRNA-1273 by Moderna and the chinease vaccine. She said, vaccine development is lengthy and complex process which takes time, but harmonization at different level will fasten the process. She said, the safety and efficacy of the vaccine is very important in the vaccine development process.</span><br />''