More than four years have passed since COVID-19 was first identified. In that time more than 700 million people have fallen ill world-wide, and almost 7 million people have died from the virus.
When the virus first appeared, it was deadly. Hospitals and medical centres were overwhelmed with patients and couldn’t keep up. We didn’t really know how it started, how it was spread, or how best to react. Since then, we have improved our hygiene habits and learned to manage our fears. We have also developed treatments to combat the virus and vaccines to protect ourselves.
You may not be aware of it, but we are currently (in early spring of 2024) experiencing the second largest surge of Covid infections globally since the pandemic began. Fortunately, these days, symptoms are mild for most people—a sore throat, a runny nose, and maybe body aches and fever—more like the flu or a bad cold. As the virus has mutated over time, the tendency has been for it to become more contagious but less harmful.
Even so, the very young, the very old, pregnant people, and anyone who is immune compromised or has an underlying lung condition can still experience severe symptoms and complications and may need to be hospitalized. Although the heightened pandemic danger has passed for the most part, we should continue to be mindful of passing along any sort of infection to vulnerable people in our communities.
COVID-19 stands for COronaVIrus Disease 2019, named for the year it was discovered. This disease is caused by the Severe Acute Respiratory Syndrome CoronaVirus 2, or SARS-CoV-2, virus. This is one of many Corona viruses, a large family of respiratory viruses that causes disease in both humans and animals.
Corona viruses are named for the crown-like spikes on the surface of the virus molecules that can be seen under a microscope. Corona means “crown” in Latin.
There is no Covid-1 or Covid-10, but because all viruses mutate and evolve, there have been multiple strains and variants of this disease.
A virus needs a living host to survive. Once it manages to enter a host, it quickly replicates and spreads. As it replicates, small “copying errors” are transferred through the viral DNA and RNA that cause the virus to change and evolve.
When enough small mutations accumulate, we say that a new variant has emerged. When a variant can be shown to have different biological characteristics than the parent virus, we call it a new strain (or lineage).
All viruses mutate as they move through host populations, but the rate of change differs from one virus to another. Covid has a moderately rapid and dynamic mutation rate, but not quite as rapid as the influenza virus.
Some mutations or changes in nucleotide chains may simply be errors, while others happen in response to the environment as the virus encounters a host’s immune response or infects someone who has developed an immunity to an older variant.
Around the world scientists continue to study variants of the SARS-CoV-2 virus and share information to global data bases , such as the PANGO database, so that governments and pharmaceutical companies can base their decisions on most current information possible.
Researchers track features such as transmissibility, immunity, and severity of illness for each variant and then classify them as:
Although the situation has been improving, the SARS-CoV-2 virus is still circulating at high levels around the world and viral mutation is unpredictable, so health authorities remain vigilant.
The most common form of the virus now circulating include the JN.1 and BA.2.86 variants of the Omicron strain. In most places these are VOI and not VOC.
The basic precautions remain the same:
Researchers around the world are continuing to develop potential treatments for Covid-19. The United States Food and Drug Administration has approved several drugs for use in hospital and in= emergency circumstances. These include:
Other potential treatments include antiviral drugs under development such as favipiravir and merimepodib, anti-inflammatory therapies and corticosteroids to mitigate organ damage, and immune-based therapies such as convalescent plasma or monoclonal antibodies.
Neither the parasite prevention drug ivermectin nor the anti-malarial drugs hydroxychloroquine and chloroquine have proven to be effective against Covid-19 and can have serious negative effects if used improperly.
When a person is exposed to a disease but does not get sick, we say they have developed an immunity. This happens when the body knows how to produce antibodies to that disease. Antibodies are proteins that can neutralize or destroy antigens—another name for foreign invaders such as viruses, bacteria, fungi, and toxins that can make us sick.
Antibodies are produced by specialized white blood cells called B cells that divide and multiply to release millions of antibodies into the blood stream and lymphatic system.
Antigens have molecules that are different from those in our bodies. When the immune system recognizes an antigen, it produces antibodies that attach themselves to the antigens and neutralize them.
When you get sick, for example with chicken pox, your immune system eventually figures out how to make antibodies that can destroy the chicken pox virus. The next time those same antigens appear, your body knows just what to do so you don’t get sick. You have naturally developed an immunity to chicken pox.
Vaccines help our bodies develop immunity without having to get sick. There are several different types of vaccines with slightly different mechanisms, but they all work to teach the body’s immune system to recognize an invader antigen and give it a “blueprint” for making an antibody that will effectively destroy it.
After a vaccination our bodies build immunity by practicing a new immune response, which sometimes results in mild symptoms such as fever. This is a sign that the body is building immunity, not that it is getting sick. Vaccines do not use live virus, they do not and cannot cause a Coronavirus or any other infection, and they do not change or influence our genes.
Thanks to vaccines, we can now avoid many diseases that once caused severe illness and death such as polio, measles, mumps, rubella, diphtheria, smallpox, hepatitis, and many others.
Both natural immunity (from getting sick and recovering) and vaccine-induced immunity last a long time, but sometimes the immune system gets out of practice, or the virus mutates so much that the old antibodies don’t work anymore, and you need an immune booster.
The flu virus mutates very quickly and can cause severe illness in old and immune compromised people, which is why researchers track mutations in the virus and develop a new flu vaccine every year.
The Covid virus also mutates quickly, although not quite so fast as the flu virus. To ensure you are protected against the current variants you should stay up to date with available vaccines.
When a disease spreads rapidly to many people we call it an epidemic, and when it cannot be confined to a certain geographical area but spreads across the globe, we call it a pandemic. The Covid-19 pandemic started in China in late 2019 and, because the virus was so virulent and our world is so interconnected, the disease quickly spread to all countries, putting a huge strain on our health care systems and causing major upheavals in our lives.
Now more than four years have passed. As more and more people develop an immunity to the Covid-19 virus, and we create better protections and treatments the virus will become endemic. It will not disappear, but we will know how to manage it and keep it at bay.
In the meantime, take good care of yourself and your loved ones, and do what you can to stay healthy and keep from passing on the illness to others.
For current information on Covid-19, visit the website maintained by the World Health Organization or one managed by the health and safety agency for your region, for example The Center for Disease Control and Prevention in the US, the European Centre for Disease Prevention and Control, or the AfricanCDC.