India has approved the world's first DNA coronavirus vaccine for emergency use for people aged 12 and above. It's developed by Zydus Cadila and is India's second domestically-developed jab, after Bharat Biotech's Covaxin. Dr. Alice Tan, an internist at MizMedi Women's Hospital in Seoul, gives her professional insights on this DNA vaccine, and the difference between the existing RNA and mRNA vaccines.