1. What is the second wave?
Pandemics are caused by new pathogens to which the majority of society is not immune. This allows them to spread globally. Pandemics are not common, but the flu is one of the more common cases. What usually happens is the spread of a new version of the flu around the world, which then recedes – like a tsunami. In a few months, however, it may return and spread to large parts of the world again.
2. What are the prospects?
In Asia, there are signals of a second wave of risk. Travel restrictions were imposed and affected more than 100 million people in the Chinese province of Jilin, near the North Korean border, after dozens of cases were found in cities there in May, a month after anti-infection measures were lifted in Wuhan. the spread of the coronavirus. Schools in Jilin have been closed and tens of thousands of people quarantined.
Small outbreaks also broke out in South Korea and Hong Kong in May, while much of the rest of the world is still struggling to control the first wave of infection. Measures in most countries have restricted the movement of people, which has slowed the spread of the virus but left many residents vulnerable to the infection once they start coming out again.
3. What stopped the first wave?
The flu epidemic can be temporarily overcome by the change of seasons. It is also possible for the virus to infect a large proportion of people in most areas, allowing them to build up immunity.
In the case of the coronavirus, however, countries around the world have introduced strict measures to stop the movement of people and social distance, to ensure that the virus can not easily spread.
4. How does the virus come back?
There are different possibilities. In the case of influenza – its return occurs in cooler weather, which can affect the coronavirus. The pathogen may also mutate. This is another feature of the flu, which is constantly evolving. In the autumn of 1918, a second wave of the historical outbreak of influenza occurred, which accounted for much of the deaths in the pandemic. Some researchers believe that this is caused by a mutation that makes the virus unrecognizable to most people’s immune systems.
Another important variable is the movement of the virus to populations that have not been exposed before and have no immunity. In addition, on April 24, the World Health Organization said there was still no evidence that people who had recovered from Covid-19 had antibodies and were protected from re-infection.
5. What can the second wave prevent?
The WHO recommends phasing out traffic restrictions so that the effect of easing measures can be assessed before moving towards their complete abolition.
In any case, experts say, the key to keeping the number of new infections low without quarantining entire countries is to conduct more tests, identify the infected, isolate them and track their contacts.
6. Why was there no second wave of SARS?
Between 2002 and 2003, the spread of SARS in Asia did not become a global pandemic. Although caused by a coronavirus, the disease was not as contagious as Covid-19. Its spread was limited mainly to hospitals and other places where people came into close contact with infected patients.
Ebola is another pathogen, relatively new to humans. There have been recurrent outbreaks of Ebola in Africa, but although the virus is highly contagious in some conditions, it was not contagious enough to spread worldwide, like Covid-19.