Hi, i am from india. is it like until we find the vaccine against corona virus, death toll in china can increase? why it takes time to develop a new vaccine?

Basics: Vaccines used for humans must undergo testing to assure their safety. In the late 70's a swine flu vaccine was rushed & resulted in more injury & death that the flu that year. The death toll will increase over time as it does with the flu until the process is contained. No vaccine treats this or any other virus, it only helps make populations resistant to its effects.

Vaccine development: Unfortunately there is not a shelf full of vaccines ready for the next infection of interest! However, we do have vaccines for viral infections known to be fatal to many more people than the coronavirus and we should be encouraging their use, e.g. flu vaccine. A new vaccine needs to be tested for safety before it can be administered to many people.