What Is COVID-19?

COVID-19 is a virus that keeps changing. Researchers are working on ways to halt the virus that caused a worldwide epidemic. Here's what you should know. 

The coronavirus (COVID-19) pandemic has sickened people around the world.  

Within a few months after the novel coronavirus was first known to cause illness, the World Health Organization (WHO) warned countries to prepare for a pandemic. Countries continue to monitor and attempt to control the spread of new variants (mutations of the original virus).

• For live statistical updates, visit this coronavirus tracker, with cases by state in the U.S. broken down here. You can also track the virus with the Johns Hopkins Whiting School of Engineering interactive virus dashboard. You can find the number of cases in your county here.
• For more information on the virus itself and its effect on the U.S. population and the world at large, visit this special web page from the Centers for Disease Control and Prevention (CDC).
• You can keep track of the CDC’s prevention and vaccine guidelines here.
• The U.S. federal public health emergency declaration ended May 11, 2023, but the CDC noted the spread of the virus did not end.

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What is COVID-19?

The infectious agent, first detected in Wuhan City, China, in late 2019, belongs to a large family of coronaviruses. The “corona” label comes from crown-like spikes seen on pathogens when coronaviruses are under a microscope.

Mostly, coronaviruses infect bats, pigs, and some other small mammals. Coronaviruses can mutate and move from infecting only animals to humans, what scientists call a “spillover event,” the National Institute of Allergy and Infectious Diseases (NIAID) explains. Then a coronavirus can be transmitted person-to-person.

The pandemic was caused by a new type of coronavirus in humans, which WHO named Coronavirus Disease 2019 (COVID-19). Because early reports of the initial COVID-19 outbreak in Wuhan seemed associated with people who visited a large seafood and live animal market in the city, animal-to-person spread was believed to be the cause.

The CDC reports person-to-person contact spreads the disease, most likely from respiratory droplets produced when an infected person coughs or sneezes.

Like flu viruses, COVID can mutate, with some variants being more dangerous than others.

Understanding the coronavirus

In all, there are hundreds of coronaviruses that infect animals, but only seven are known to sicken humans.

Most types of coronaviruses cause only mild-to-moderate upper respiratory tract illnesses in people, with symptoms much like the common cold, according to the NIAID. Since 2002, however, three types of coronaviruses have caused severe disease in people:

• SARS (first recognized in late 2002)
• MERS (Middle Eastern Respiratory Syndrome), a disease found in camels that can sicken humans
• COVID-19

When people hear animals can have coronaviruses, there can be unfounded worries and rumors about pets potentially spreading the disease. Yet there is no reason to think any animals or pets in the U.S. might be a source of infection with the coronavirus, according to the CDC.

Progress in halting the virus

While the coronavirus can be fatal, those at highest risk are people who already have pre-existing health problems, especially people over 60 and those with heart or lung disease, diabetes, or autoimmune diseases. Men are also more likely to have a severe case of the disease than women.

Most COVID-19 cases are mild, but some people experience long-term effects, called long COVID. The virus may also increase the risk of developing autoimmune disease and heart problems.

Scientists have drawn on what they learned from other outbreaks of coronavirus illness in humans — especially deadly SARS, which swept across the globe in 2003, primarily through air travel — to prevent the spread of COVID-19. Quarantines and travel restrictions, which were important to halting SARS, have been in effect at times to keep COVID from spreading further.

Previous research into the SARS and MERS outbreaks helped scientists to quickly assess the new coronavirus and find ways to prevent and treat COVID-19, the NIAID points out.

Within two weeks of the discovery of the new coronavirus, NIAID researchers had already figured out how the virus enters cells, and a global effort was launched to contain, prevent, and treat the COVID-19.

Treatment may include:

• Nirmatrelvir, ritonavir (Paxlovid)
• Molnupiravir (Lagevrio)
• Remdesivir (Veklury)

There is some indication that molnupiravir may spur mutations of the virus itself.

According to CDC data, more than 80 percent of Americans age 5 and older have received at least one dose of a COVID vaccine. About 70 percent are fully vaccinated against the coronavirus. Almost 95 percent of Americans at especially high risk because of their age — seniors 65 and older — have had at least one shot of the vaccine, and about 94 percent are fully vaccinated.

If you are vaccinated or planning to get the shot or boosters, your top concerns about the CDC guidelines for the vaccine and booster jabs are likely to revolve around what you can now do safely. The rates of people who have received booster shots are lower than those who received the first rounds of the vaccine.

Vaccine side effects

The CDC has reported common side effects of the vaccine, including pain, redness, swelling, and some flu-like symptoms. There are, however, reports of adverse events, including anaphylaxis, thrombosis, Guillain-Barre Syndrome, and death. You can keep track of adverse side effects here.

Some people, most frequently adolescents and young males, have developed myocarditis and pericarditis following vaccination. Myocarditis is inflammation of the middle muscle layer of your heart wall. Pericarditis is irritation and inflammation of the pericardium, the sac-like thin membrane surrounding your heart.

Common sense virus prevention strategies are important

First off, get vaccinated for COVID-19.

If you’ve followed the course of COVID-19 in the U.S. and guidelines from the CDC, reported as the course of the coronavirus pandemic has changed, it’s no surprise that guidelines continue to result in some controversy.

The bottom line is the guidelines are not federal mandates, and states can make their own guidelines.  

With guidelines continuously changing, you will need to check with your state’s board of health to see whether there are required rules for mask wearing, even for those who are vaccinated.

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