Transmission Dynamics of COVID-19 and Impact on Public Health Policy

B Shayak; Mohit Manoj Sharma; Richard H Rand; Awadhesh Kumar Singh; Anoop Misra

Coronaviruses are naturally hosted by bats and it is believed that most human coronaviruses are derived from the bat reservoir [7, 8] . Genomic sequence studies of COVID-19 have identified nearly 50%, 79% and 96% similarity to MERS-CoV, SARS-CoV and bat SARS-related coronavirus respectively [9, 10, 11] . The specific route of transmission to human from natural reservoirs is still yet to be known, however, some studies suggest that pangolins could be the intermediate mammalian hosts. Since the spike proteins of SARS-CoV-2 are nearly identical to those of a virus isolated from pangolin, it is believed that pangolins could have provided a partial spike gene to SARS-CoV-2, to infect mammals [12, 13] . A recent study has also shown a development of new variations at the functional sites in the receptor-binding domain of the spike of SARS-CoV-2 and viruses from pangolin, likely caused either due to a natural selection or due to mutations and recombination, or both [14] .