The concept of "severe COVID-19" can be a frightening one, especially when the term itself is so often misunderstood or confused with having self-assessed severe symptoms of COVID-19.
Approximately 80% of those who test positive for COVID-19 have mild to moderate illness.1 But adults 50 and older and people of any age with certain underlying health conditions are at high risk of progression to severe COVID-19. That adds up to two in five people worldwide who are at increased risk for severe COVID-19.2 In the U.S. approximately 75% of adults are at high risk of progression to severe illness.3
According to the CDC, "Severe outcomes of COVID-19 are defined as hospitalization, admission to the intensive care unit (ICU), intubation or mechanical ventilation, or death."4
“Severe illness is different from having symptoms that are subjectively assessed as ‘severe,’” says Florin Draica, MD, MBA, Senior Medical Director, COVID-19 Antiviral Team Lead. “For example, a patient can have severe headache and cough (severe symptoms) but the disease, from a clinical spectrum, can still be mild-to-moderate.”
“In order to take the right steps for ourselves and to protect our high-risk populations, it's important to understand the differences between having subjectively diagnosed severe symptoms and having severe COVID-19 disease," Draica says.
Here's what you need to know:
Severe symptoms of mild or moderate COVID-19 vs. severe COVID-19
There is no “typical” COVID-19 infection. Those who test positive for the virus can fall along a broad spectrum from asymptomatic to critically ill.5 Some people who get COVID-19 may not notice any effects while others may experience muscle or body aches, cough, sore throat, shortness of breath, congestion, headache, and loss of taste or smell.5,6 Although these symptoms may range from mild to moderate or even feel more serious, these cases would not necessarily be classified as severe COVID-19.5
"The disease can progress to severe or critical illness as the symptoms worsen, but also as the patient has additional specific symptoms that define the severe or critical stages of COVID-19 that you don't have in the mild or moderate illness,” Draica explains.
Again, the severity of symptoms is not what defines having severe COVID-19 at all. Instead, a diagnosis of severe COVID-19 is based on specific clinical signs, including a respiratory rate over 30 breaths per minute, oxygen saturation below 94%, and lung infiltrates over 50%, as shown on radiographs.5
COVID-19 symptoms such as headache, fever, or a runny nose can be managed at home with over-the-counter pain relievers if the disease is mild or moderate and if the patients are not at high risk of progression to severe illness, Draica says. Patients who have a high risk for progression to severe illness and have COVID-19 should seek care from a healthcare provider and discuss whether a COVID-19 treatment might help to prevent disease progression, even if their symptoms are mild. Patients with severe or critical illness should be hospitalized and may need intensive care or supportive ventilation.3,7
Symptoms can be mild or severe while a patient has a mild to moderate COVID-19, according to Draica. "The disease management should be driven by the patient's risk status, not the subjective severity of symptoms," he says, explaining that these symptoms can worsen quickly, just as the disease can progress quickly to severe or critical, if the patient is at high risk for severe illness.
“The severity of symptoms is what gets a lot of attention, but that's not necessarily the right focus,” says Draica. “What should be the focal point is the patient's risk for progression to severe illness.”
Recognizing the risk of severe illness
Those who are age 50 or over or have certain underlying medical conditions, including chronic asthma, COPD, kidney disease, heart conditions or cardivascular disease, diabetes, obesity or being overweight, or people who are immunocompromised due to certain medications, organ or stem cell transplants, or have AIDS, face a greater risk of a COVID-19 infection progressing to severe illness.2,7 In the United States, approximately 75% of adults have at least one underlying health condition that places them at high risk of developing severe COVID-19.3
Despite the risks, a large proportion of patients who are at high risk and eligible for outpatient COVID-19 treatment do not receive those treatments, Draica says. He believes the oversight is related to COVID-19 patients not being aware of their high-risk status, and this not seeking care, and thus not seeking care, and their focus on symptom severity, not the risk of developing severe disease.
To complicate matters, Draica notes that two-thirds of those who have underlying conditions are unaware that they are at high risk of progression to severe illness after testing positive for COVID-19, making them less likely to seek testing or care.
To address this, Pfizer partnered with the global digital health company Ada Health Inc. to develop the Ada Health COVID-19 Care Journey. This online platform asks a series of questions for patients to learn if they have underlying conditions or other factors that put them at risk for progression to severe COVID-19. If they test positive for COVID-19, they can answer the questions and then use the information to talk to a healthcare provider via telehealth about treatment options if they test positive for COVID-19.
The importance of prioritizing protection
With the COVID-19 public health emergency having ended, we're in a different point in the pandemic.8 Still, COVID-19 was the fourth leading cause of death in United States in 2022, and the virus continues to spread.9
Staying up-to-date on COVID-19 vaccines reduces the risk of serious illness, hospitalization, and death from COVID-1910, and for appropriate patients, taking prescribed medication after testing positive for the virus can reduce the risk of developing severe COVID-19.11
Understanding what constitutes a high risk for severe COVID-19, staying informed on preventive, detection, and treatment options, and being proactive in discussions with healthcare providers about that risk is also crucial.
Those who have one or more high-risk factors should speak with a healthcare provider even if they have mild symptoms. Remember, symptom severity is not predictive of your risk for severe illness and it’s possible to develop severe COVID-19 even if you have mild symptoms or you’re asymptomatic.5
“Everybody should be alert and test to limit the spread of the disease to others who may be at high risk for severe illness,” Draica says. “If somebody is at high risk or uncertain of their risk and has symptoms or a known exposure, they should consult with a healthcare professional.”
