COVID-19 Symptoms: Omicron vs. Delta

• Omicron symptoms are usually milder compared to Delta symptoms
• Both Omicron and Delta can cause severe illness for people that belong to a risk group for COVID-19
• The symptoms of Omicron vs. Delta are quite similar, although Omicron targets the upper respiratory tract more, resulting in symptoms such as sneezing, a runny nose, and a sore throat 
• Omicron is currently the dominant strain of the coronavirus worldwide 

Omicron and Delta have been the dominant strains of the coronavirus lately. Because of the worldwide circulation of these two variants, it’s essential to know the difference between the symptoms they cause, their transmissibility, the duration of symptoms, and the possible severity of illness they may cause. Understanding these two variants’ differences is crucial for public health strategies and your information and protection.  

Omicron and Delta symptoms have been a worldwide cause of concern since these variants emerged. The Delta variant was first detected in India in March 2021 and quickly spread worldwide. In November of the same year, Omicron was detected in South Africa and became the dominant variant worldwide. Currently, the variants in high circulation are all variants of Omicron. 1

To assess the implications for public health and the need for additional safety measures, the WHO created a system in which all variants have been categorized according to their potential impact on transmissibility, immunity, and severity.  

Based on these characteristics, variants of the coronavirus can be divided into: 2 3

• Variants of concern, which are viruses for which there’s evidence of an increase in transmissibility or disease severity.
• Variants of interest, which are viruses that have mutated in such a way that there may be an increase in transmissibility or disease severity.
• Variants under monitoring, which are variants that may increase transmissibility or disease severity, but the evidence is weak or hasn’t been properly assessed yet. 
• De-escalated variants, which are variants that have been de-escalated as they’re no longer circulating, have an impact on the overall situation of COVID-19, or they aren’t associated with any concerning health problems. 

After close monitoring, the Delta variant has been de-escalated, as it no longer circulates at high levels. For Omicron, the categorization depends on the exact mutation of the virus. Some variants of Omicron are de-escalated due to their little impact on public health, in contrast, other variants are under monitoring as they have been detected in large quantities worldwide, but the effect has yet to be assessed. 4

The symptoms of Omicron vs Delta are quite similar, although some differences are important to understand. In general, Omicron symptoms are more present in the upper respiratory tract, which makes it harder to differentiate this virus from other respiratory illnesses, such as the common cold. Delta symptoms may also affect the lower airway tract, including the lungs. To have an overview of the possible Delta symptoms vs. Omicron symptoms, we've created the following table: 5

It’s important to note that symptoms of Delta and Omicron may vary in intensity and character. If you think that you may have been infected with either one of the variants of the coronavirus, then it’s essential to get tested and to self-isolate until you have received your test results. 

If your test returns positive, then you should quarantine for at least 5 days. After this, you can end your quarantine depending on whether or not you still have a fever. Even if you're feeling better after your quarantine, keeping your distance from people at a high risk of developing severe symptoms for at least 5 more days, even if they're vaccinated, remains crucial.

In general, both Omicron and Delta symptoms can become severe for certain individuals at a high-risk individuals need to take the necessary precautions against infection with the coronavirus, as they have a higher risk of being hospitalized, needing ventilation, and risk of death. 7

The duration of Omicron and Delta symptoms may vary from person to person. It can depend on various factors, such as age, vaccination status, and underlying health conditions. 

Generally, Omicron and Delta symptoms may last from a few days to several weeks. If your symptoms persist beyond that time frame, you should seek medical attention, as you may have long-COVID. 8

The symptoms of the Delta variant may be more severe than the ones of the Omicron variant, resulting in a higher risk of severe illness, hospitalization, and even death. This risk is significantly higher for unvaccinated people or people in a risk group.

The biggest difference between Delta and Omicron lies in the transmissibility of both coronavirus strains. Although the Delta variant is estimated to be about twice as transmissible as the original strain of SARS-CoV-2, Omicron is even more transmissible. Due to its high transmissibility, Omicron could spread easily and became the current dominant strain of the coronavirus. 9

The treatment for Omicron vs. Delta depends on the severity of your symptoms. For most people, the infection will only cause mild to moderate symptoms, which can be treated at home with home remedies such as: 10 11

• Taking pain medication such as paracetamol, ibuprofen or naproxen
• Getting plenty of rest
• Staying hydrated by drinking enough water, especially if a fever is present
• Taking cough medicine and sitting upright instead of lying down in case you have a cough 

Suppose you're at risk for severe symptoms due to COVID-19. In that case, you may be eligible for antiviral treatment, which can prevent serious complications such as hospitalization and death by helping your immune system to defend itself against the coronavirus.

Whether or not you are a high-risk patient, you should always monitor your Omicron or Delta symptoms closely to be ready to take action if they worsen. You should contact your doctor if: 12

• You’re gradually feeling worse
• You have difficulty breathing when standing upright
• You feel very weak, and basic tasks are becoming too difficult
• You’re shaking or shivering
• You still feel unwell after a month

Omicron vs. Delta symptoms differ in several ways. While Delta variant symptoms include a loss of taste and smell and a persistent cough, Omicron symptoms are more likely to have a sore throat, a runny nose and sneezing. As both variants may cause hospitalization, it’s important to use preventative measures such as wearing masks and getting vaccinated. 

Q: How do you know if you have Omicron or Delta? 

A: Through genetic sequencing of the virus, scientists can determine which variant you’ve been infected with. However, many cases of COVID-19 are not sequenced, as the treatment for both variants remains the same. 

Q: Is Omicron milder than Delta? 

A: The symptoms of Omicron are often milder than the ones for Delta, although both variants may put certain individuals at risk for severe complications and hospitalization. 

Q: How to test for Omicron vs. Delta? 

A: You can get tested with an antigen, antibody, or a PCR test to determine whether or not you’ve been infected with COVID-19. 

Q: How deadly is Omicron vs. Delta? 

A: For most people, Omicron and Delta only cause mild to moderate symptoms which go away independently. For others, however, these variants may cause severe illness.