Pandemics do not last forever and when they end, it usually is not because a virus has disappeared or has been eliminated. Instead, they can settle into a population, becoming a constant background presence that occasionally flares up in local outbreaks.
Since the beginning of the COVID 19 pandemic, epidemiologists and public health specialists have been using mathematical models to forecast the future in an effort to curb the coronavirus’s spread.
The reality is infectious disease modelling is tricky.
Epidemiologists warn that “models are not crystal balls,”
Even sophisticated versions, like those that combine forecasts or use machine learning, cannot necessarily reveal when the pandemic will end or how many people will die.
A combination of public health efforts to contain and mitigate the pandemic — from rigorous testing and contact tracing to social distancing and wearing masks — have been proven to help.
Given that the virus has spread almost everywhere in the world, though, such measures alone can’t bring the pandemic to an end.
All eyes are now turned to vaccine development, which is being pursued at unprecedented speed.
Yet experts tell us that even with a successful vaccine and effective treatment, COVID-19 may never go away. Even if the pandemic is curbed in one part of the world, it will likely continue in other places, causing infections elsewhere.
Even if it is no longer an immediate pandemic-level threat, the coronavirus will likely become endemic. This means a slow sustained transmission will persist. The coronavirus will continue to cause smaller outbreaks, much like seasonal flu.
"We may not completely eliminate [the coronavirus], but if you get it down to such a very low level, and enough of the population is protected—either by a vaccine or by previously having been infected—then you'll develop a degree of herd immunity that you won't have an outbreak,"
Many emerging viruses become part of the viral ecology. The four coronaviruses that cause the common cold are endemic, circulating in the population, and the influenza strains that cause seasonal flu predictably surge each year.
The SARS outbreak in 2003 did not go the same way due to biology and behavior: It was much less transmissible than the virus that causes COVID-19, countries contained it quickly, and it has pretty much disappeared.
The only disease that has been eradicated through vaccination is smallpox. Mass vaccination campaigns led by the World Health Organization in the 1960s and 1970s were successful, and in 1980, smallpox was declared the first human disease to be fully eradicated.
It is the only disease to this very day that has been fully eradicated.
Once they emerge, diseases rarely leave.
Whether a virus is bacterial, viral or parasitic, virtually every disease pathogen that has affected people over the last several thousand years is still with us, because it is nearly impossible to fully eradicate them.
The good news is that viruses can sometimes become milder with time, treatments are already becoming more effective and vaccines can be improved.
Will we be able to conquer this disease? That is the greatest question of our time right now, but it will be a matter of time and science.