The government has said it is worried after the discovery of the new mutant strains of COVID-19 in India and has called for extra caution. Four cases of South African variant and one case of Brazil mutant have been found in India. There are 187 cases of the UK strain in India. The new strains are more transmissible and more deadly. The latest cases have been made public at a time when Covid cases in certain parts of the country, like Maharashtra, are rising. The big worry is that a mutation, labelled E484K, found in all these variants, helps the virus evade antibodies, thereby raising doubts and questions over the efficacy of vaccines against these strains.