Viruses and bacteria are a nuisance; can't we just eradicate them all? It can be tempting to think that way, because viruses and bacteria are the cause of many ailments and deaths. But unfortunately, it's not that simple. Both bacteria and viruses have their place in nature, and we depend on them. It is bacteria that break down dead organic material so that it can be reused. It is fungi, bacteria, and protozoa that live in the rumen and break down the cellulose in grass so that cows, sheep, and other ruminants can get nutrition. Human digestion also depends on microorganisms. In the large intestine, there are many microorganisms that help with digestion. If this bacterial flora is disturbed, one can get an upset stomach. Microorganisms also have a role on the skin and mucous membranes. An American study has concluded that we have more microorganisms on and in our bodies than we have cells in our bodies. But they are so small that they nevertheless only make up about 3 kg of an adult man.

Bacteria and protozoa are quite hardy creatures. As long as they get moisture and nutrients, they can withstand quite a lot. If they don't get these, many of them can hide inside a capsule waiting for better times. But they have an Achilles' heel. They eat! They have a metabolism, and we can trick them by feeding them something they cannot tolerate. For example, penicillin.

The word virus actually means poison. It is a bit worse with viruses. Viruses do not eat. We cannot give them poisonous food. We have to fight them in other ways, preferably by stimulating and supporting the body's own defense against viruses. We can inject antibodies into the blood. The antibodies find the virus particles and bind to them. This prevents the virus from attaching to a cell, and they act as a label that allows the virus to be detected and destroyed by the body's own defense system. The common method is to inject dead or weakened viruses into the body. The virus is not capable of making us sick, but the immune system learns to make antibodies on its own. We call this vaccination. It is a method that can be used against both bacteria and viruses. Once the body has learned to recognize a virus and produce antibodies against it, the immune system remembers this for a shorter or longer time. In some cases, for a lifetime.

But the very best thing is that we don’t let the virus into our bodies at all. We can stay away from those who are infected. We can wash our hands and surfaces. We can disinfect with chemicals or heat. We can use masks and gloves. I mentioned earlier that viruses are fragile things. They consist of a few strands of RNA or DNA, genetic material, which is the recipe for making new virus particles. These are encapsulated in a shell of proteins. The surface of this shell has 'hooks' that can attach to a cell. When that happens, there are mechanisms that open the cell wall and let the genetic material into the cell. There, it takes over the cell's machinery and starts it producing viruses. It continues to do so until the cell bursts and releases all the virus particles, the virions. Viruses are, as I said before, fragile things. It takes little to destroy a virion so that it doesn’t work. Errors also occur in the production process; mutations happen. That is when the genetic material is copied incorrectly. Then the new virus is different from the old one. Almost all mutations fail. They cause the virus to stop working. But occasionally, a rare mutation provides an advantage. It's like winning the lottery – for the virus, that is. Such mutations can make the virus's coat slightly different so that our immune system doesn't recognize it. This is often the case with cold viruses. They mutate so frequently that it's not worth the effort to try to develop a vaccine. The same is true, to some extent, with the flu. We make vaccines, but it's uncertain how effective they are if the virus has changed significantly along the way.

Coronavirus. It got its name because under the microscope it has an aura around it, somewhat resembling how we see the sun through a coronagraph, a special telescope that blocks out the solar disk so that one can study the sun's glowing atmosphere. Corona actually means crown. SARS-CoV-2 is what we call a zoonosis, a pathogen that can infect both animals and humans. It is also considered highly contagious and has a high fatality rate for some of those who become infected.

The world has chosen different strategies to combat this virus, ranging from denying that it exists at all to complete lockdown and isolation. Some countries reacted quickly, some late. Our neighboring country, Sweden, believed that the best approach would be for as many people as possible to get the disease so that natural immunity in the population would occur, the much-discussed herd immunity. That is when so many are immune that those who are infected cannot infect many others, and the infection rate is below one. Then the epidemic will die out. The infection and disease will continue to exist, but not as an epidemic. The infection rate for Norway is currently at 0.66. But that is due to lockdown and isolation measures, not herd immunity. Norway has chosen a strategy of lockdown and isolation. It will not eradicate the disease. It could have done so if it were a limited area. As it stands, the spread is global, and we must assume that even if one were to manage to eradicate the virus in Norway, it would always come back. We simply cannot isolate ourselves from the rest of the world forever.

It will take a very long time for Norway to achieve natural resistance in the population. Due to the strategy we have chosen, few people are infected. To achieve the effect of herd immunity, at least 60% of the population must have antibodies. Nevertheless, I believe Norway has chosen a favorable strategy, provided that a vaccine becomes available within a reasonable time. By vaccinating, immunity is achieved without experiencing the disease.

There is also a big difference in how severely the disease affects each individual. This may be due to some cross-immunity stemming from other illnesses, like flu, colds, etc. Another factor that can play a role is the infectious dose. If a person is exposed to a massive dose of the virus, the body has less chance to fight it compared to if the dose is smaller, allowing the immune system time to respond before a large number of cells are infected. It is also the case that, regardless of the disease, not everyone gets sick. During the Black Death, many fell ill, but not all. The Spanish flu did not affect everyone. Not everyone gets the flu, and not everyone contracted measles, rubella, chickenpox, and so on. Some are naturally immune without any detectable reason.

The pandemic leaves its mark on the economy. When people miss work due to illness or quarantine, it results in losses. We see that many politicians and lobbyists are more concerned about the country's (or their own) economy than about the health of the population. The government is quite generous in handing out saved funds to large, international players while small businesses have to struggle and manage as best they can. Some predict a global recession that will last for decades to come.

The world's wealth is very unevenly distributed. While some wallow in luxury, others are dying of hunger. Could it be time for a revision of our economic systems? We consume the Earth's resources to produce superfluous and unnecessary things. Could it be time to return to the essentials? We travel around the world in search of experiences and entertainment in exotic settings. Could it be time to become a bit more 'introspective' and rather seek amusement in our immediate surroundings? We pull fish from the sea, transport it halfway across the globe to have it processed before sending it back the same way. Could it be time to put an end to such madness? We are so busy that goods are sent by energy-consuming and environmentally damaging trucks instead of by ship or railway.

There are many things that don't add up. Pandemics are certainly not the only problem we are struggling with. Not even the worst.