In January this year, Nature asked 119 immunologists, infectious-disease researchers and virologists working on the pandemic whether it could be eradicated. Almost 90% of respondents think that coronavirus will become endemic — meaning that it will continue to circulate in pockets of the global population for many years to come. Eradicating this virus right now from the world is unrealistic.
However, failure to eradicate does not mean that death, illness or social isolation will continue on the scale 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 mean that societies tolerate the seasonal deaths and illnesses they bring without requiring lockdowns, masks and social distancing.
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 will determine the societal costs of SARS-CoV-2 for 5, 10 or even 50 years in the future :
Childhood virus
Five years from now, when childcare centres call parents to tell them that their child has a runny nose and a fever, the COVID-19 pandemic might seem a distant memory. But there’s a chance the virus that killed more than 1.5 million people in 2020 alone will be the culprit.
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.
Vaccines and herd immunity
Countries that have begun distributing COVID-19 vaccines soon expect to see a reduction in severe illness. But it will take longer to see how effectively vaccines can reduce transmission. Data from clinical trials suggest that vaccines that prevent symptomatic infection might also stop a person from passing on the virus.
Similar to flu?
The 1918 influenza pandemic, which killed more than 50 million people, is the yardstick by which all other pandemics are measured. It was sparked by a type of virus known as influenza A, which originated in birds. Almost all cases of influenza A since then, and all subsequent flu pandemics, have been caused by descendants of the 1918 virus. These descendants circulate the globe, infecting millions of people each year. Flu pandemics occur when populations are naive to a virus; by the time a pandemic virus becomes seasonal, much of the population has some immunity to it. Seasonal flu still has a significant toll globally, claiming roughly 650,000 lives per year.
Measles-like virus
If SARS-CoV-2 vaccines block infection and transmission for life, the virus might become something akin to measles. “It’s probably less likely [than other scenarios] but it’s still possible.
Animal reservoirs
The future of SARS-CoV-2 will also depend on whether it establishes itself in a wild animal population. Several diseases brought under control persist because animal reservoirs, such as insects, provide chances for pathogens to spill back into people. These include yellow fever, Ebola and chikungunya virus.
Summary
The path that SARS-CoV-2 might take to become an endemic virus is therefore challenging to predict, but society does have some control over it. In the next year or two, countries can reduce transmission with control measures until enough people have been vaccinated either to achieve herd immunity or to drastically reduce the severity of infections. That would significantly reduce deaths and severe disease. However, if countries abandon strategies to reduce spread and let the virus reign unchecked, then the darkest days of the pandemic may still be ahead of us. click full article .
