The coronavirus is here to stay
Eradicating the coronavirus is an unrealistic goal at this stage, scientists say.
08 March 2021 | International
A Nature survey shows many scientists expect the virus that causes Covid-19 to become endemic, but it could pose less danger over time.
In January, Nature asked more than 100 immunologists, infectious-disease researchers and virologists working on the coronavirus whether it could be eradicated. Almost 90% of respondents think that the coronavirus will become endemic — meaning that it will continue to circulate in pockets of the global population for years to come.
“Eradicating this virus right now from the world is a lot like trying to plan the construction of a stepping-stone pathway to the Moon. It's unrealistic,” says Michael Osterholm, an epidemiologist at the University of Minnesota in Minneapolis.
But failure to eradicate the virus does not mean that death, illness or social isolation will continue on the scales seen so far. The future will depend heavily on the type of immunity people acquire through infection or vaccination and how the virus evolves. Influenza and the four human coronaviruses that cause common colds are also endemic: but a combination of annual vaccines and acquired immunity means that societies tolerate the seasonal deaths and illnesses they bring without requiring lockdowns, masks and social distancing.
More than one-third of the respondents to Nature's survey thought that it would be possible to eliminate SARS-CoV-2 from some regions while it continued to circulate in others. In zero-COVID regions there would be a continual risk of disease outbreaks, but they could be quenched quickly by herd immunity if most people had been vaccinated.
“I guess COVID will be eliminated from some countries, but with a continuing (and maybe seasonal) risk of reintroduction from places where vaccine coverage and public-health measures have not been good enough,” says Christopher Dye, an epidemiologist at the University of Oxford, UK.
“The virus becoming endemic is likely, but the pattern that it will take is hard to predict,” says Angela Rasmussen, a virologist from Georgetown University, who is based in Seattle, Washington
This is one scenario that scientists foresee for SARS-CoV-2. The virus sticks around, but once people develop some immunity to it — either through natural infection or vaccination — they won't come down with severe symptoms.
The virus would become a foe first encountered in early childhood, when it typically causes mild infection or none at all, says Jennie Lavine, an infectious-disease researcher at Emory University in Atlanta, Georgia. Scientists consider this possible because that's how the four endemic coronaviruses, called OC43, 229E, NL63 and HKU1, behave. At least three of these viruses have probably been circulating in human populations for hundreds of years; two of them are responsible for roughly 15% of respiratory infections.
Daniela Weiskopf, an immunologist at the La Jolla Institute for Immunology in California and her colleagues are still tracking the immune memory of people infected with COVID-19 to see if it persists.
If most people develop life-long immunity to the virus, either through natural infection or vaccination, then the virus is unlikely to become endemic, she says.
But immunity might wane after a year or two — and already there are hints that the virus can evolve to escape it.
More than half the scientists who responded to Nature's survey think waning immunity will be one of the main drivers of the virus becoming endemic.
Because the virus has spread around the world, it might seem that it could already be classed as endemic. But because infections continue to increase worldwide, and with so many people still susceptible, scientists still technically class it as in a pandemic phase. In the endemic phase, the number of infections becomes relatively constant across years, allowing for occasional flare-ups, says Lavine.
To reach this steady state could take a few years or decades, depending on how quickly populations develop immunity, says Lavine. Allowing the virus to spread unchecked would be the fastest way to get to that point — but that would result in many millions of deaths.
“That path has some huge costs,” she says. The most palatable path is through vaccination.