People hope that the COVID-19 epidemic will end as soon as possible. What could be in store for the epidemic? We don’t have a crystal ball to show us the future, but we can get some clues from the past.
Both SARS and the virus that caused COVID-19 are known as coronaviruses, so it may be helpful to compare the 2003 SARS epidemic with the current one. This could present us with the best scenario, where the virus is brought under control through public health interventions.
The best way to contain the virus in both outbreaks is to identify cases as early as possible and isolate the infection.
In both cases, large-scale control measures were implemented. In 2003, the SARS epidemic ended in China after about six months. And it was eradicated worldwide after infecting over 8,000 people and killing nearly 800.
In addition, some scientists have argued that the hot and humid climate of early summer has contributed greatly to the fight against SARS. The same topic is ongoing on COVID-19.
But the new coronavirus is smarter. The latest research shows that its protein spike design allows it to maintain its grip on a cell 10 to 20 times more firmly than SARS. This explains why the new coronavirus is more contagious than SARS. It also has an incubation period potentially longer than 20 days, much longer than that of SARS. All this suggests that containing it is much more difficult.
But that doesn’t mean it’s a patient virus. It needs to move quickly because its single-stranded nucleic acid structure is so fragile that it could easily be destroyed by powerful immune systems. Therefore, it causes acute symptoms in the host to quickly leave and jump from another, infecting as many people as possible in a shorter period of time. But at the same time, this strategy sounds the alarm for humans to activate further measures to combat it.
That’s why SARS disappeared so quickly and completely. In fact, there have been only three cases since 2004, all due to a laboratory leak. So what happened to SARS? Where it went? Scientists believe the new coronavirus was hidden in its natural host, the bat. In 2017, in a remote cave in Yunnan province, virologists identified a single population of horseshoe bats. They host viral strains with all the genetic building blocks of what jumped to humans in 2003.
In addition, the government severely banned the central basin between bat and human, the civet cat after the outbreak, preventing SARS from crossing the line. This may explain why MERS is still persecuting humans in the Middle East. The central reservoir, the camel, is an important part of local life in some parts of the region. But we still have no idea of the central tank of the new coronavirus.
Another ending to an epidemic is what has been called “burn out”. This is what happened to the Zika virus epidemic that hit South America between 2015 and 2016. Given that Zika cannot infect the same person twice, thanks to the antibodies generated by the immune system, the epidemic reaches a stage in which there are too few people left to be infected for the transmission to sustain, just as the flames of the fire consume all the oxygen in a room and become extinct. This is not a desirable scenario because it will cause multiple infections and deaths.
The last chance paints a future where the virus is not contained. The 2009 H1N1 pandemic virus could not be contained in the United States and therefore spread all over the world. Since then, this virus has circulated as a seasonal flu. The evolution will allow the virus to find a balance between virulence and transmission. Many viruses, such as HIV, will take on a milder form, trading for a wider spread. If so, the new coronavirus can return seasonally and join the milder coronavirus strains that infect people like colds or common pneumonia.