The plague that devastated medieval Europe,
The Spanish flu killed more people than World War II.
The pandemic COVID-19 that has thrown the world into chaos
What we need to know about infectious diseases

The year 2020, when COVID-19 swept the globe, is likely to be remembered as a pivotal turning point in human history.
There are even those who say that future history will be divided into BC (Before Corona) and AC (After Corona). The shockwaves brought about by the invisible virus have shaken countries around the world, and we all feel the power of infectious diseases every day.
The 17th volume of the Future Thinking Power Plant series, "Nature's Revenge, Infectious Diseases," is a book that provides children with easy-to-understand information about infectious diseases that have accompanied human history, including COVID-19, the disease we are currently experiencing, as well as the plague, leprosy, and influenza.

Also, calling it the Hong Kong flu or the Wuhan coronavirus creates the problem of hatred or discrimination against those who live in or have passed through Hong Kong or Wuhan.
Some people might think that it is natural for them to do so since they are the ones who spread the infectious disease, but unless the infectious disease was intentionally spread as a biological weapon, patients who contract the infectious disease are also victims.
You can isolate yourself, i.e., limit contact with people, to prevent them from becoming infected.
But even if they are isolated, they are also patients whom our society must help overcome the infectious disease through the best possible treatment.

What if we treat certain people as criminals out of fear of infectious diseases? People often hide out of fear of stigmatization and criticism, rather than the infectious disease itself.
This makes it even more difficult for health authorities and medical staff to know who has the disease, and the infection spreads further without anyone knowing.
Ultimately, only when we help those who contract infectious diseases report themselves and receive proper treatment can our entire society find safety from the infectious disease crisis.
As such, there are many things to consider when naming a virus.
--- p.
102

Among viral diseases, there is one that is highly suspected of having the potential to be used as a biological weapon.
It is smallpox, which the World Health Organization (WHO) declared eradicated decades ago.
Thanks to the cowpox vaccination, the first vaccination in human history, this disease was eliminated, and smallpox was finally eradicated from humankind.
We haven't been vaccinated against smallpox for a long time.
In other words, except for some elderly people who had smallpox in their childhood and middle-aged people who had been vaccinated against smallpox, the rest of the population is defenseless against smallpox.
This is why there are warnings that smallpox could be used as a powerful biological weapon at any time.
This is an open secret, but it is also the reason why many countries, including ours, still stockpile smallpox vaccines.
Because we have to prepare for an unexpected war.
Of course, diseases like smallpox should not be used in warfare.
--- pp.
108-109

When a place is untouched by human hands, it is often easy to think of it as undeveloped.
But this is only from the people's perspective.
The fact that some people call some countries in Africa or Southeast Asia uncivilized also comes from a perspective that does not recognize other societies and cultures.
However, this society, with its jungle-like nature and culture different from that of the West, already has order.
The untouched jungle means that countless animals, plants, and microorganisms such as bacteria and viruses are maintained in balance.
If a virus multiplies too much, many of the virus's hosts die, disrupting the balance.
Then, the virus and the host disappear together, and the place is filled by other animals and viruses, and this phenomenon continues to repeat itself.

But what if those trying to develop the jungle encounter these viruses and bacteria? Our immune systems aren't trained to defend against unfamiliar bacteria or viruses.
The principle of vaccination is to inject bacteria or viruses that are dead or have already died, so that our body's immune system learns how to fight them.
When we encounter a virus or bacteria we've never encountered before, our immune system becomes confused and has a hard time blocking their attacks.

--- pp.
153-156