Since December 2019, the world has been significantly impacted by the emergence of the coronavirus (COVID-19).
This highly contagious virus sparked a global pandemic, resulting in more than six million confirmed deaths worldwide to date.
Thankfully, advances in prevention and treatment methods have helped to keep millions safer.
In this article, we’ll cover the basics of COVID-19, including information on how it’s transmitted, the symptoms it can cause, and which risk factors can put you at higher risk for serious illness.
We’ll also cover which treatment and preventive methods are effective and when you should reach out to a medical provider for care.
What is Coronavirus (COVID-19)?
The coronavirus disease, commonly referred to as COVID-19 or COVID, is a highly contagious viral disease that first emerged in December 2019 in Wuhan, China.
Since then, it has spread around the world, causing the first global pandemic of its scale in the 21st century.
Coronaviruses are a group of viruses that cause illness both in humans and animals.
They are of different types, including the SARS-CoV-2, which caused the recent pandemic of the respiratory disease called COVID-19.
All viruses change over time, including the virus that causes COVID-19 (SARS-CoV-2). Viruses replicate and evolve in order to survive.
In some cases, these changes (mutations) don’t have a significant impact on the properties of a virus, like how it spreads or its associated disease severity.
But some mutations can affect these properties and sometimes pose an increased risk to public health.
The World Health Organization (WHO) has been working closely with researchers, expert networks, and national authorities to monitor the evolution of variants of the virus that causes COVID-19.
To help inform the public of their findings, they’ve created three core classifications for the different COVID variants:
- Variant of Concern (VOC): Variants classified as a VOCs are associated with one or more of the following changes that pose a risk to global health:
- Increased transmissibility
- Increase in virulence, including more severe disease, increased hospitalizations or deaths
- Reduction in neutralization by antibodies generated during previous infection or vaccination
- Decrease in the effectiveness of public health measures, including diagnostics, treatments, or vaccines
As of May 2022, current circulating VOCs include Delta and Omicron (and their descendent lineages). Previously circulating VOCs include Alpha, Beta, and Gamma.
- Variant of Interest (VOI): Variants classified as VOIs have specific genetic changes that are predicted to affect virus properties, including:
- Disease severity
- Immune, diagnostic, or therapeutic escape
- Prevalence (increase in COVID cases)
As of May 2022, there is no circulating variant of interest.
- Variant Under Monitoring (VUM): Variants classified as VUMs are variants with genetic changes that are suspected to affect the properties of the virus, and that may pose a future risk, but there isn’t enough evidence to determine the epidemiological impact of those changes. Importantly, variants classified as VUMs may be added or removed as more evidence becomes available.
COVID-19 can cause a wide array of symptoms, but it most often causes symptoms that affect the lungs and respiratory system.
However, some people who contract COVID-19 don’t experience any symptoms at all.
This is called asymptomatic infection.
When symptoms do occur, they can include:
- Fever or chills
- Shortness of breath
- Difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
- Skin rashes
Symptoms can appear between 2-14 days after exposure to the virus.
Though most people with COVID-19 have mild symptoms, some people can become severely ill.
Getting vaccinated can reduce the likelihood of serious illness in most people.
Extended COVID Symptoms
People who become infected with COVID-19 can continue to experience symptoms long after their initial infection (even if their initial infection was asymptomatic).
When a person experiences new, recurring, or continuing symptoms that last for one month or longer after initial infection, this is referred to as long COVID (also called post-COVID).
Extended COVID symptoms can also be wide-ranging. They can include:
- Increased respiratory effort
- Chest pain
- Heart palpitations
- Stomach issues
- Brain fog
- Impaired daily function and mobility
- Discoloration and swelling on the hands and feet
- Severe inflammation
- Loss of smell and/or taste
Though the exact prevalence of long COVID is still unknown, one report estimates that more than half of people infected with COVID-19 experience long COVID.
COVID-19 is caused by a virus called SARS-CoV-2. SARS-CoV-2 is part of the coronavirus family.
The word “corona” means “crown” in Latin and refers to the appearance of coronaviruses, whose spike proteins form a crown-like shape.
The coronavirus family includes many viruses, some of which cause mild infections (like head or chest colds) and others that are responsible for more severe diseases, including severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS).
COVID-19, like all coronaviruses, spread easily. COVID-19 is a highly contagious virus that spreads through respiratory droplets produced by the mouth and nose.
COVID-19 can be spread through three main ways:
- Breathing in air that contains respiratory droplets from an infected person who is breathing or speaking nearby. People who are closer than six feet from an infected person are more likely to get infected.
- Having respiratory droplets from an infected person land on your eyes, nose, or mouth, usually when an infected person coughs or sneezes close by.
- Touching your eyes, nose, or mouth with hands that have the virus on them.
Importantly, anyone infected with the virus can spread it to others, even when they have no symptoms.
Most people who are infected with COVID-19 and experience mild illness can recover at home.
In most cases, you can manage symptoms with:
- Medications for pain and fever including acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) such asibuprofen.
- Staying hydrated
- Nasal irrigation (if you’re experiencing a COVID-19 headache)
- Over-the-counter cough and cold medications to help with the symptoms such as Mucinex or Sudafed.
However, people at risk for severe illness from a COVID-19 medication are eligible for certain treatments after being diagnosed.
These treatments can reduce the chances of being hospitalized or dying from the disease.
In these cases, the decision to prescribe additional treatment is based on the individual’s risk factors; not everyone will receive prescribed treatment.
Treatments that have received emergency use authorization (EUA) from the Food & Drug Administration (FDA) for use in people more at risk for severe illness include:
These treatments target specific parts of the virus to stop it from multiplying in the body. Examples of antiviral treatments include:
- Nirmatrelvir with ritonavir (Paxlovid), which can be taken at home by mouth
- Remdesivir (Veklury), which requires intravenous (IV) infusions at a healthcare facility
- Molnupiravir (Lagevrio), which can be taken at home by mouth and must begin within five days of the start of symptoms
These treatments help the immune system to recognize and respond to the virus more effectively.
Unfortunately, the effectiveness of these treatments may vary depending on the type of variant present.
Examples of monoclonal antibody treatments include Bebtelovimab, which requires a single IV injection administered by a healthcare provider
There are several things you can do to help prevent yourself from getting infected with the COVID-19 virus:
- Get vaccinated: COVID-19 vaccines are safe and effective at preventing infection, severe illness, and death from COVID-19. COVID-19 vaccines are currently authorized for people aged five and older.
- Masks: Wearing a mask in crowded and/or indoor settings is a critical public health tool for preventing the spread of COVID-19. But keep in mind that certain masks are more effective than others (N95 and K95 masks are both more protective than cloth masks), and it’s important to wear your mask properly so that it fits snugly on your face and covers both your nose and mouth.
- Social distancing: Avoiding contact with people who may be sick with COVID-19 and maintaining a distance of six feet or more when around people from other households can help to prevent infection.
- Improve ventilation: When gathering with small or large groups, improving ventilation can help to prevent the spread of COVID-19. This can include moving gatherings outdoors when possible or improving ventilation indoors by opening doors and windows and using air filtration systems.
- Wash your hands thoroughly and often: Get into the habit of washing your hands with soap and water for at least twenty seconds when caring for someone who’s sick, after being in a public space, before and after preparing food, after using the restroom, and after blowing your nose, coughing or sneezing.
- Get tested: If you’re experiencing symptoms of COVID-19 and/or have been recently exposed to someone that tested positive for COVID-19, getting tested can help you to prevent spreading the virus to others.
Getting vaccinated is the best way to slow the spread of COVID-19.
The federal government provides COVID-19 vaccines free of charge to everyone in the United States aged five years old and older, regardless of immigration or health insurance status.
Getting vaccinated and staying up-to-date with your vaccines can help to prevent future infection, serious illness, and death, even if you’ve been previously infected with COVID-19.
There are two COVID-19 vaccines approved by the FDA:
- Comirnaty (Pfizer-BioNTech), approved for people 16 years and older
- Spikevax (Moderna), approved for people 18 years and older
Both the Moderna and Pfizer-BioNTech vaccines are two-dose mRNA vaccines.
Children aged 5-17 are also eligible to receive the Pfizer-BioNTech COVID-19 vaccine through EUA.
Those who are eligible for single booster shots include everyone 12 years and older who completed their primary series of Pfizer or Moderna over five months ago or longer (or three months ago for people who are severely or moderately immunocompromised).
A third vaccine, Janssen (Johnson & Johnson), has been granted EUA for use in people 18 years and older for whom the other approved COVID-19 vaccines are not accessible or clinically appropriate.
Single boosters of either the Pfizer or Moderna vaccine are recommended two months after receiving the primary dose of the Janssen vaccine.
A second booster of either the Pfizer or Modern vaccine is also currently recommended for adults ages 50 and older and people who are moderately or severely immunocompromised at least four months after the first booster.
Anyone can get infected with COVID-19, but certain people are at risk for severe illness, hospitalization, and death.
People at risk for severe illness as a result of COVID-19 infection include:
Older adults are more likely to be hospitalized and die from COVID-19.
Adults aged 50 and older are at increased risk of severe illness regardless of vaccination status, and people aged 85 and older are most likely to get very sick.
People with certain medical conditions
Certain conditions can put you at higher risk of severe illness from COVID-19, including autoimmune conditions. Some conditions that can put you at higher risk include:
- Chronic kidney disease
- Chronic liver disease
- Chronic lung disease
- Cystic fibrosis
- Neurological conditions
- Diabetes (both type 1 or type 2)
- Heart conditions
- Overweight and obesity
- Sickle cell disease
- Other immunocompromising conditions
- Taking medications that suppress the immune system
Pregnant and recently pregnant people
People who are pregnant or have recently been pregnant are more likely to experience severe illness from COVID-19. Getting COVID while pregnant also increases the risk of certain pregnancy complications.
When To See a Medical Provider
If you’re experiencing mild symptoms of COVID-19, you should talk to your medical provider.
It’s also important to isolate and manage symptoms at home to prevent the spread of the virus.
But some severe signs of COVID-19 may warrant emergency attention, including:
- Difficulty breathing
- Persistent pain or pressure in the chest
- New confusion
- Inability to stay awake or wake up
- Pale, gray, or blue-colored skin, lips, or nail beds (depending on skin tone)
- Severe dizziness or fainting
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K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.