Variants are new form of covid-19 that are evolved over a period of time. According to World Health Organization when a virus replicates or makes its copies, sometimes the genetic constitution of the virus is changed which is called "Mutation". A virus with one or more new mutations is called 'Variant' The original virus is Corona, and it causes Covid-19. The new variants keep emerging and sometimes they disappear but most of the time they emerge and persist longer. Multiple variants of corona virus that caused Covid-19 have been documented with different symptoms in United States and worldwide during this Pandemic. So far five variants of corona virus have been detected. WHO is working with scientists from all over the world to make sure that the covid vaccines administered to the people should protect them from new variants to some extent. All countries must make unanimous efforts to stop the spread of Covid 19 worldwide as much as it can be to control and prevent Mutation at any cost, it is impacting the efficacy of Covid Vaccines.