Many experts have said they expect COVID-19 to eventually become an endemic disease. Several key factors will shape the transition to endemicity globally. Yet, according to some scientists, the word “endemic” has become one of the most misused of the pandemic. Many assumptions are made when using this concept, leading to what some call misplaced complacency.
For epidemiologists, an endemic disease is a disease whose overall infection rate is static. This means that the number of people getting sick offsets what is known as the basic reproduction number of the virus. This also includes the number of individuals to whom each infected person transmits the virus.
In other words, a disease can be endemic, widespread and deadly all at the same time. Malaria killed more than 600,000 people in 2020. Ten million fell ill with tuberculosis that same year and 1.5 million died from it. These statistics show that endemic disease status does not mean that evolution has somehow tamed a pathogen so that life simply returns to normal.
So the expectation that COVID-19 will become endemic essentially means that the pandemic will not end with the disappearance of the virus. Instead, enough people will gain immune protection through vaccination and natural infection to mean there will be less transmission and therefore fewer COVID-19-related hospitalizations and deaths, even if the virus continues to circulate.
The expected continued circulation of COVID-19 contrasts with the first wave of SARS in 2003 and the Ebola virus outbreak in West Africa in 2014, when public health measures finally stopped the spread and ended both epidemics. These were both global in terms of spread, but not as severe as COVID-19. Importantly, while there are differences between viruses and settings, the comparison made by epidemiologists underscores the critical need to improve global public health infrastructure and surveillance systems to monitor and help respond to the inevitable next potential pandemic virus.
Since viruses spread where there are enough susceptible individuals and enough contact between them to sustain the spread, it is difficult to predict what the timing of the expected passage of COVID-19 to its endemic stage will be. There are dependent factors, such as the strength and duration of immune protection against vaccination and natural infection, our patterns of contact with each other, and the transmissibility of the virus.
The conversion of COVID-19 to endemic status is likely to differ significantly from what we have seen with other pandemics due to heterogeneous responses around the world, with some places committing to “zero-COVID-19” policies and others with limited or no policies. restrictions, while the variable availability and use of vaccines is another factor.
While waiting for the endemic stage, we can begin to reassess what global health professionals want to do about other preventable diseases and health security. We are in the midst of a surge of what specialists call respiratory syncytial viruses which includes not only COVID-19 but also colds and flu-like symptoms which can be much more severe in infants, the elderly and people with respiratory diseases. On a global scale, tuberculosis and malaria remain scourges that cause suffering. In other words, we have a unique opportunity to think about global health policies regarding respiratory infections.
The shift from pandemic to endemic is also psychological, as the mental satisfaction that people may seek in terms of a pandemic-specific endpoint will be lacking. Instead, societies will have to adapt to live alongside COVID-19. An endemic disease does not mean that it is not taken care of. Rather, what is needed is to shift from viewing COVID-19 as a one-time threat to viewing it as a part of everyday life that we must learn to endure.
There is no doubt that past pandemics have brought about massive changes in the way humans live and that we have come to accept them as normal. Some scientists claim that screens on our doors and windows have helped ward off mosquitoes that carry yellow fever and malaria, and that sewage systems and access to clean water have helped eliminate typhoid outbreaks. and cholera. Lessons learned from the COVID-19 pandemic in terms of disease prevention can lead to similar long-term improvements in individual and global health.