Medicosnext
An endemic virus is one that circulates normally in a certain location, being relatively constant in a population, and with quite predictable patterns. Rhinoviruses, which cause the common cold, circulate endemically around the world, and influenza is an endemic virus with epidemic and pandemic potential.
Due to widespread public health efforts and vaccination of large populations, the COVID-19 pandemic could disappear over time (like polio and small pox), or it might become endemic, albeit with sporadic outbreaks. Moreover, the transition (from pandemic to endemic) may take place at different times in different locations globally. Generally, a virus may turn endemic if it adapts to a local environment and/or has an uninterrupted supply of susceptible hosts. In the case of COVID-19, such hosts are those with low or no immunity.
At the present time, experts believe that COVID-19 is not likely to disappear like small pox, and they expect the annual number of infections to become fairly constant, with seasonal trends and some small outbreaks. Herd immunity—either from vaccination or from infection—will be key in the transition from pandemic to endemic. Due to many variables, including vaccination rates, all nations will not enter an endemic phase at the same time. The virus may continue to remain at an epidemic level for more time if there is poor vaccine coverage among the population (an epidemic is an outbreak over a short period of time in a specific geographical region, such as the Ebola virus in three West African countries from 2014–2016). Further, COVID-19 could revert from an endemic phase to an epidemic phase again in areas where immunity is likely to decline faster and there are no booster doses available.
When will it be known that the COVID-19 pandemic has transited to being an endemic? A stable level of virus transmission, with minor seasonal trends (like flu), will probably signal that the pandemic has become endemic. On November 9,2021, the World Health Organization reported, “During the week 1 to 7 November 2021, a slight upward trend (1% increase) in new weekly cases was observed…Over 48 000 new deaths were reported, a 4% decrease from the previous week. The WHO European Region reported increases in case and death incidence, while other regions reported declines or stable trends.” Experts expect countries with high vaccination rates to transition as soon as 2022 from the pandemic to the endemic phase.
