The coronavirus epidemic seems to have no end. Will we have to “live with it” forever? Will the virus eventually disappear? Can a vaccine eradicate the disease? Here are the different hypotheses and the most probable scenarios.
It has been almost eight months since the coronavirus epidemic officially became a global pandemic. More than 43 million cases have been registered, and Covid-19 has already caused more than 1.2 million deaths. In August, the World Health Organization (WHO) warned that the pandemic would be “very long”.
“This pandemic is a health crisis that happens once in a century, and its effects will be felt in the coming decades,” said the WHO Director-General Tedros Adhanom Ghebreyesus. Will we have to get used to wearing a mask forever, never kissing our loved ones again, and permanently erasing trips and concerts from our vocabulary? Hopefully not, but a return to life like it was before will probably take a while.
The virus disappears naturally
The first SARS epidemic in 2003 resulted in over 8,000 cases and nearly 800 deaths. But the outbreak was contained and the virus spread only slightly outside China. SARS-Cov-2 on the other hand is much more contagious and has affected all countries. In addition, it brings more asymptomatic cases, which makes its tracing difficult. Some had also raised the hypothesis that the virus would disappear with the summer; instead, it continued to spread actively. In short, it seems too late to consider this hypothesis of global containment. For now, however, China has managed to avoid a second wave, but at the price of its isolation from the rest of the world.
When 60 to 70 percent of the population is infected, the virus will no longer find enough hosts to become infected and the disease will be stopped. This is the hypothesis of the herd immunity advocates, who are working to have the virus circulate in young people. However, after 10 months of an epidemic and 1 million deaths, we are still far from that: according to the WHO, only about 10% of the population worldwide at most has immunity so far. In addition, several cases of reinfection have been reported and it is not known how long the natural immunity lasts. Therefore, this is another unlikely scenario.
A vaccine stops the epidemic
“Global access to coronavirus vaccines, tests, and treatments for everyone who needs them, anywhere in the world, is the only solution,” says the WHO. In theory, an effective vaccine can provide enough immunity to prevent the virus from circulating. But right now, despite an unprecedented mobilization, we are still waiting for this miracle vaccine. “The vaccine may not work or its protection may last only a few months,” warns the WHO. We also know that vaccines are less effective on older people, who are the most vulnerable. Finally, as long as a vaccine is widely available, we still have to convince enough people to get vaccinated. “Historically only smallpox has been eradicated by a vaccine,” says historian Nükhet Varlik of the University of South Carolina.
The virus becomes endemic like the cold
Four common cold coronaviruses circulate every year. “After a catastrophic outbreak, SARS-Cov-2 could eventually degenerate into a benign virus like the common cold,” says Andrew Noymer, an epidemiologist at the University of Irvine, California. The flu, which comes back every year, affects millions of people in the US alone, and causes thousands of deaths. Currently, there is no indication that the severity of Covid-19 is decreasing. However, effective treatments could be found to reduce the mortality rate, such as with AIDS.
The virus keeps coming back
“Once a pathogenic agent has developed, it is practically impossible to eradicate it completely”, warns Nükhet Varlik. Many diseases such as tuberculosis, malaria, and Ebola reappear regularly in isolated homes. They may be more or less contained by preventive measures or appropriate treatment, but this requires increased vigilance at the slightest resurgence of the epidemic. “Infectious diseases account for one-third of deaths worldwide each year,” says the historian.
Globally “How a pandemic evolves depends 50% on science and 50% on political and social measures,” says epidemiologist Sarah Cobey of the University of Chicago. And since neither scientists nor politicians know what will happen to the virus, we are forced to navigate a little blind, which is not exactly reassuring. But one thing is certain: a virus has no interest in killing its entire host population. At some point, it can become weaker or less contagious, which gives us a little pause until the next virus appears.