COVID-19 hasn’t gone away. While COVID-19 incidence and severity have decreased since early pandemic days, hospitalizations still occur year round—even in patients under 65. The virus continues to threaten patient health with severe illness, hospitalization, death, and long-term health problems.^1-3
 
Unlike other respiratory viruses, COVID-19 regularly surges in both winter and summer. Compared to influenza, COVID-19 has been associated with more than 3.5 times the risk of hospitalization for venous thromboembolism, such as deep vein thrombosis or pulmonary embolism.^1,4,5 

In addition, underlying chronic conditions lower the body’s baseline resilience, increasing the risk of severe COVID-19 in adults of any age. And while certain underlying chronic conditions increase the risk of progressing to severe COVID-19, these conditions also put patients at risk for long-term complications, regardless of age. These risks are significantly higher for patients with multiple chronic conditions. In fact, nearly 53% of US adults aged 35 to 64 live with ≥2 chronic conditions, and this cohort faces higher COVID-19 hospitalization rates than healthy seniors aged 65 and older.^6-8

Each individual reacts differently to the COVID-19 virus, which can range from asymptomatic to severe illness. Symptoms and severity are unpredictable and can change over the course of the infection. COVID-19 severity is primarily driven by patient risk factors, not initial symptoms.^6,9-11
 
High-risk factors include certain underlying conditions, age (50+), and vaccination status.
People with underlying conditions have a higher risk of severe COVID-19, regardless of age. The risk increases significantly for patients with ≥2 chronic conditions.^6,7
 
Evidence also indicates that the impact of severe COVID-19 can persist well beyond the acute phase. After initial infection, patients face higher rates of hospitalization and death, significant lingering health issues, and the cumulative damage caused by repeat infections, also known as post–COVID-19 condition (PCC), which includes long COVID.^3,12

Each individual reacts differently to the COVID-19 virus, which can range from asymptomatic to severe illness. Symptoms and severity are unpredictable and can change over the course of the infection. COVID-19 severity is primarily driven by patient risk factors, not initial symptoms.^6,9-11
 
High-risk factors include certain underlying conditions, age (50+), and vaccination status. People with underlying conditions have a higher risk of severe COVID-19, regardless of age. The risk increases significantly for patients with ≥2 chronic conditions.^6,7
 
Evidence also indicates that the impact of severe COVID-19 can persist well beyond the acute phase. After initial infection, patients face higher rates of hospitalization and death, significant lingering health issues, and the cumulative damage caused by repeat infections, also known as post–COVID-19 condition (PCC), which includes long COVID.^3,12

SARS-CoV-2 enters cells by latching its spike protein onto widespread receptors, allowing the virus to attack multiple organ systems, including the lungs, heart, kidneys, and pancreas.^13,14
 
Once inside, unchecked viral replication triggers an inflammatory response across these organ systems. This severe inflammation can directly injure the endothelium, leading to vascular damage and disrupted blood clotting. This systemic damage begins during the acute phase of the infection, laying the groundwork for post–COVID-19 conditions (PCC) like long COVID.^12-14
 
While many people recover quickly, others—particularly those who experienced severe COVID-19—develop PCC, which can cause widespread organ damage lasting for weeks, months, or even years.^10,15

Evidence shows that patient risk factors—not initial symptoms—are the primary drivers of severe disease progression. People of all ages with certain underlying medical conditions—including diabetes, heart conditions, smoking, and obesity—face an increased risk of severe COVID-19. These risks are much higher for patients with multiple chronic conditions.^6,7,11
 
People who are 50 years and older still face a higher risk of severe outcomes, along with those who are unvaccinated or not up to date on COVID-19 vaccinations. In addition, some racial and ethnic minority groups face greater healthcare barriers—like lacking insurance, transportation, or paid leave—and experience higher rates of COVID-19 hospitalization, ICU admission, and death at younger ages.⁶

While age (50+) and vaccination status are the strongest individual risk factors for progressing to severe COVID-19, people of all ages with underlying conditions and risk factors face higher risk, including⁶:

• Cardiovascular disease
• Respiratory disease
• Diabetes
• Kidney disease
• Certain racial and ethnic minority groups
• Smoking (current or former)
• Obesity

Patients with ≥2 chronic conditions are especially at risk for developing severe COVID-19. In addition, some racial and ethnic minority groups face greater healthcare barriers—like lacking insurance, transportation, or paid leave—and experience higher rates of COVID-19 hospitalization, ICU admission, and death at younger ages.^6,7

Severe COVID-19 does more than just increase the risk of hospitalization and death—it can fundamentally alter a patient’s long-term health. The root of this lasting impact lies in how the virus attacks the body, transforming an acute infection into long-term health problems. How does it do this?^10,13
 
Virus enters
SARS-CoV-2 enters human cells by latching onto specific cell receptors. Because these receptors are found throughout the body, the virus has a gateway to multiple vital organs.^13,14
 
Inflammation begins
During the initial, acute phase of the infection, patients with lower baseline resilience—the body’s pre-infection ability to recover from illness—are highly vulnerable. The virus can exploit these preexisting weaknesses, causing long-term organ damage.^13,14
 
Damage spreads
This widespread inflammation can contribute to severe COVID-19 and lay the groundwork for PCCs like long COVID. Instead of fully recovering, patients may experience a secondary wave of health challenges^10,12,13,15:

• New-onset medical conditions
• Exacerbation of preexisting conditions
• Multiorgan damage

Testing
Testing according to guidelines can help ensure patients are treated in a timely and appropriate manner. See CDC, FDA, and IDSA testing recommendations below.^16-19

Treatment
COVID-19 treatments may help patients at high risk for progression to severe COVID-19, even if symptoms are mild. Depending on the treatment, they must be started within 5 or 7 days of symptom onset.^6,20,21

The CDC recommends prescribing antivirals to significantly decrease the risk of hospitalization and death in patients with high-risk factors. Antiviral treatments are designed to help stop the virus from multiplying.^6,22

Slower viral clearance has been linked to greater symptom severity and higher risk of post–COVID-19 conditions like long COVID.²³