The key difference between Delta and Omicron is that Delta causes more severe symptoms in patients, while Omicron causes less severe symptoms in patients.
SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus 2) is a strain of coronavirus that causes COVID-19 disease. It is responsible for respiratory illness and the ongoing COVID-19 pandemic. This virus primarily transmits between people through close contact via aerosols and respiratory droplets. Moreover, it enters human cells by binding to angiotensin-converting enzyme 2 (ACE2) membrane protein. There are many variants of the SARS CoV-2 virus. World health organization has currently declared greater concern about five variants: Alpha, Beta, Gamma, Delta, and Omicron.
CONTENTS
1. Overview and Key Difference
2. What is Delta
3. What is Omicron
4. Similarities – Delta and Omicron
5. Delta vs Omicron in Tabular Form
6. Summary – Delta vs Omicron
What is Delta?
Delta is a variant of the SARS-CoV-2 virus that causes more severe symptoms in COVID-19 patients. This variant was discovered in India in late 2020. It had spread to over 179 countries by November 2021. This variant showed evidence of higher transmissibility, severe symptoms, and reduced neutralization by May 2021. In June 2021, the World Health Organization indicated the Delta variant was the dominant strain globally. The Delta (B.1.617.2) genome has 13 mutations that produce alterations in the amino acid sequences of the proteins it encodes. The list of spike protein mutation includes 19R, G142D, Δ 156-157, R158G, L452R, T478K, D614G, P681R, and D950N. Four mutations, D614G, T478K, L452R, P681R, among these mutations (which are in the virus’s spike protein code), are of particular concern.
This variant also has been referred to as the “Indian variant” as it was originally detected in India. However, the Delta variant is only one of three variants of the lineage B.1.617. Delta variant is thought to be partly responsible for the deadly second wave of the pandemic of India. Later, it also contributed to the third wave in Fiji, the United Kingdom, and South Africa. In the United Kingdom, one study found that the most reported symptoms for this variant were headache, sore throat, fever, and runny nose. Furthermore, the treatment options suggest for delta variant include casirivimab, etesevimab, imdevimab, sotrovimab, remdesivir, supplemental oxygen, and corticosteroids. Vaccination is the best protection against the Delta variant.
What is Omicron?
Omicron (B.1.1.529) is a variant of the SARS-CoV-2 virus that causes less severe symptoms in patients. This variant was first reported to the World health organization in November 2021 from South Africa. The Omicron variant multiplies 70 times faster than the Delta variant in the bronchi of the lungs. But evidence suggests it is less severe than the previous strains of the SARS-CoV-2 virus. Omicron is less able to penetrate deep lung tissue. Moreover, Omicron infections are 91% less fatal than the delta variant, with 51% less risk of hospitalization. However, considering its high rate of spread and its ability to evade double vaccination, Omicron is still of great concern. Omicron has 60 mutations. Out of them, 50 are non-synonymous mutations, while 8 are synonymous mutations, and 2 are non-coding mutations. A total of thirty mutations affects spike protein.
The commonly reported symptoms after contacting this variant are cough, fatigue, congestion, runny nose, headache, sneezing, and sore throat. A unique reported symptom of Omicron is night sweats. Furthermore, the treatment options suggested for the Omicron variant include corticosteroids (dexamethasone), IL6 receptor blockers (tocilizumab), neutralizing monoclonal antibodies such as sotrovimab. Vaccination with Pfizer seems to be effective against the Omicron variant as well.
What are the Similarities Between Delta and Omicron?
- Delta and Omicron are two different variants of the SARS-CoV-2 virus.
- They belong to the B lineage.
- Both variants have high global occurrence.
- Both variants have a high number of mutations compared to the original SARS-CoV-2.
- These variants can be detected through quantitative PCR.
- Vaccination is the best protection against both variants.
What is the Difference Between Delta and Omicron?
Delta is a variant of SARS-CoV-2 virus that causes more severe symptoms in patients, while Omicron is a variant of SARS-CoV-2 virus that causes less severe symptoms in patients. Thus, this is the key difference between Delta and Omicron. Furthermore, Delta has 13 new mutations compared to the original SARS-CoV-2 virus, while Omicron has 60 new mutations compared to the original SARS-CoV-2 virus.
The below infographic presents the differences between Delta and Omicron in tabular form for side by side comparison.
Summary – Delta vs Omicron
Delta and Omicron are two different variants of SARS-CoV-2 virus that belong to the B lineage. They have high global occurrence compared to earlier variants such as Alpha, Beta, and Gamma. Delta causes more severe symptoms in patients, while Omicron causes less severe symptoms in patients. So, this is the key difference between Delta and Omicron
Reference:
1. Tian, Dandan, et al. “The Global Epidemic of the SARS-COV-2 Delta Variant, Key Spike Mutations and Immune Escape.” Frontiers, Frontiers, 1 Jan. 1AD.
2. “Classification of Omicron (B.1.1.529): SARS-COV-2 Variant of Concern.” World Health Organization, World Health Organization.
Image Courtesy:
1. “Covid-19-coronavirus-delta-variant” (CC0) via Pixabay
2. “Spike omicron mutations side” By Opabinia regalis – Own work (CC BY-SA 4.0) via Commons Wikimedia