Why do vaccines need preservatives? Preservatives are added to vaccines to inhibit microbial and fungal growth. They are especially needed for multi-dose vials, because when those containers are opened and closed multiple times, harmful germs could get inside. Thimerosal Thimerosal is the most widely used preservative in vaccines. Organic chemist Morris Kharasch synthesized the compound… Read more

How is a vaccine developed and approved? The process of developing and testing a vaccine takes several years and involves three stages: exploratory stage, pre-clinical stage, and clinical development. Exploratory Stage The first stage in developing a vaccine involves years of laboratory research, which typically spans from 2-4 years. Researchers identify which natural or synthetic… Read more