The germs among us
It was easier for us to understand the heavens than to fathom what is inside our bodies. We already understood for the most part how objects, including the planets, move and stayed still before we understood germs. Isaac Newton had already laid this out in the late 1600s. But it was only in the 1800s that we had definitively found and accepted that there was tiny “stuff” in the air (some we consider as “living” and some we are not sure qualifies as “living”) that cause sickness in plants and animals (humans are animals even if we forget this a lot) and that they reproduce inside us and spread through different ways.
The size of a human hair is about 75,000 nanometers. Bacteria is about 1000 nanometers. But a virus is only 20-400 nanometers. This is one of the reasons why it is very difficult to treat a viral disease – you have to come up with ingenious ways to first see it, and then devise incredibly tiny filters to catch it and then attack it.
Bacteria and viruses are among the “stuff” that scientists call “pathogens” (“pathos” which means “feeling” or “suffering” and “gen” which means “born”) – those that cause diseases. The 5 kinds of pathogens are viruses, protozoa, bacteria, fungi, and worms. The smallest of these are viruses.
Bacteria was discovered before viruses, because scientists until the end of the 1800’s had found ways to make tiny filters that could catch bacteria, but were surprised to find that infection still persisted. This could only be so because what was causing the infection may have been a lot smaller.
Bacteria could be seen through a “regular” microscope. This kind of microscope had its beginnings in 1590 and went through great improvements, including the one by Galileo in 1609. Robert Hooke, the one who coined the term “cell” in 1665, also had a hand in it, as did Leeuwenhoek in the 1670’s – he was the one who first described “spermatozoa” when he saw it through his self-designed high-powered single lens microscope. Robert Koch in 1882 also designed the bacteria that could cause tuberculosis.
But a virus could only reveal itself through an electron microscope, and this was not invented until 1931 by Ernst Ruska and Max Knoll.
Viruses could be considered the weirdest among the 5 pathogens because they do not have their own cells. And if “cell” is how we define the “basic unit of life,” then they are not alive. As such, they do not have “cell walls.” But they move and reproduce by using the cells of the hosts that they invade. They can infect everything that have cells, including bacteria. Viruses move because they are like freelancers – they are not attached to any institutions, but they have “wifi,” literally wired with strands of RNA and DNA molecules which carry their own genetic material, protected by a protein coat and another layer of material. These are the ones that move in and wreak havoc inside cells.
Viruses take on many shapes – like snowflakes. A coronavirus was named as such because when seen under an electron microscope, it has “crowns” like the sun’s crown. A flu virus, meanwhile, is spherical in shape. The shapes of the virus determine how a virus works and and attaches itself to host cells.
A virus can find various ways to enter a life form through carriers: through coughing and sneezing, through fecal matter, b coming into contact with blood that has it, or by sexual contact. When it enters a host, it will invade the cell, taking over that cell’s machinery so that it can reproduce itself. While a bacteria is specific to a disease (local), a viral infection spreads throughout your other cells (systemic).
A disease caused by bacteria can be treated by antibiotics because antibiotics generally work by attacking the cell wall of the bacteria. As viruses do not have cell walls, there is nothing that antibiotics can do to treat viruses. Your own immune system generally would have to be the one to be strengthened so you could fight off the march of viruses in your own cells.
For the nastier viruses like polio, measles, smallpox, and chickenpox, vaccination is the most effective way to prevent them. Vaccination is when a substance (the “foreign” chemical or the “good” twin of the virus) is formulated in such a way that when it is introduced into your own body, your own immune system will be on high alert and will be able to recognize the virus and fight it off with its own defense mechanism.
Each kind of virus will call for its own kind of vaccine, because the latter will depend on the virus structure. Our immune system should be able to know it when it sees it and know the kind of “weapons” to use and to what extent they will be unleashed to destroy the virus. That is why it is so essential that when public health experts say they are still studying a virus, this includes the possibility of figuring out how soon they can come up with a vaccine.
This is also why vaccination of the large majority of the population is paramount. Viruses will survive and flourish and spread if they find more and more people who have not been vaccinated. Once that happens, the viruses gain enough power to be an epidemic (throughout communities) or pandemic (throughout the world). As long as the vast majority has been vaccinated against these viruses, these viruses will be relatively silent.
The newly discovered coronavirus that started in Wuhan, China seems to have come from animals, though they are not sure yet which animal it is and how they jumped to humans. They know this because a significant number of the people health experts examined were exposed to the meat market. They also know that it may be spreading because of coughing or sneezing, similar to the flu, as a good number tested have also been exposed to people with respiratory illness.
Panicking is a normal reaction to the discovery of a virus, but we have to try harder as the general public to respond – which means you should wear a mask if you are in public places, and take the strictest precautions when in contact with animals. We should also listen to our local health officials as well as the World Health Organization. (READ: DOH says it's ready in case new coronavirus reaches PH)
This is a chance for us to get to understand what a virus is, why vaccination is essential, and how science could be on your side regardless of your sketchy relationship with it when you were still in school – that is, on the side of life. – Rappler.com
Maria Isabel Garcia is a science writer. She has written two books, "Science Solitaire" and "Twenty One Grams of Spirit and Seven Ounces of Desire." You can reach her at firstname.lastname@example.org.