Omicron Variant B.1.1.529 : Key Facts You Need to Know in 2025

Scientists first spotted the omicron variant when they noticed unusual PCR test results showing S-gene target failure in November 2021 in South Africa. This discovery alerted researchers to a major change in the virus's structure. The new strain, B.1.1.529, quickly took hold, and by mid-November, over 70% of sequenced samples from South Africa's Gauteng province showed the variant's distinctive mutation pattern. The WHO designated it as a variant of concern and named it Omicron.

This unprecedented genetic makeover gave Omicron some remarkable new traits:

• Stronger binding to ACE2 receptors on human cells (5 times higher than the original virus)

• Preference for infecting upper airways rather than lungs

• Knowing how to evade antibodies from prior infection or vaccination

BA.1 and BA.2, Omicron's subvariants, multiply much faster in airways despite their compromised fusion ability.

A newer study published in 2025 by researchers revealed something unexpected about Omicron's milder nature. The mutations boost the release of specific immune epitopes that HLA molecules recognise in up to 82% of people worldwide.

The subvariants continued to evolve, with new subvariants, such as NB.1.8.1 and LF.7, emerging in India and globally. Both NB.1.8.1 and LF.7 types are sub-lineages of the JN.1 variant. JN.1 is part of the Omicron BA.2.86 family—it spreads more easily yet causes milder symptoms than earlier variants of Omicron.

Our understanding of the omicron variant has grown by a lot in the four years since we first found it. Scientists now have a better understanding of how this coronavirus strain continues to shape public health policies worldwide.

The rise of COVID variants brought us the NB.1.8.1 sublineage in late 2024, which stands as the latest major mutation. This strain spreads just as quickly as earlier omicron versions but hasn't become more severe. Vaccination campaigns that target these newer subvariants have helped keep hospitalisation rates under control.

Today's Omicron looks quite different from its original form. The virus has become more adept at evading immunity while causing milder illnesses in vaccinated individuals. Testing methods now catch emerging subvariants faster, which lets health officials respond more quickly.

Here's what omicron symptoms look like in 2025:

• Nasal congestion and sore throat

• Mild fever

• Fatigue

• Some sublineages cause more stomach-related symptoms, such as diarrhoea, nausea, and reduced appetite.

• Loss of smell/taste - now shows up in fewer than 10% of cases

The new omicron variant tracking systems around the world have made our response better. However, some regions continue to struggle with limited genetic testing resources.

Symptoms of the new Omicron variant typically appear 2 to 14 days after exposure to the virus, with most people exhibiting signs around day 5. The virus can spread even before symptoms start—typically 1 to 2 days earlier—and may continue to spread for 2 to 3 days after symptoms appear.

Certain groups of people are vulnerable to getting this variant infection, including:

• Older adults

• People with weakened immunity

• Pregnant women

• People with existing systemic conditions, such as lung problems, diabetes, kidney or liver disease, cardiac conditions, and obesity

Medical treatments have advanced significantly since Omicron first appeared. New antiviral medications are more effective against current strains, and hospitals have refined their approaches based on years of hands-on experience.

The omicron virus story illustrates how COVID-19 evolved from a frightening new disease to an illness that most people can manage. This doesn't make it any less serious for vulnerable groups, who still need strong protection measures. Wearing masks in public places, getting vaccinated for those aged 60 and above, and avoiding overcrowded areas are key steps to protect against infection.

Since its emergence in 2021, Omicron has reshaped how we view and respond to COVID-19. What began with global concern over its rapid spread has gradually turned into a deeper understanding of its behaviour. Scientists have decoded Omicron's unique structure with its 50 mutations, and they've paid special attention to the 32 changes in the spike protein.

Our response capabilities have grown stronger with the virus. Health systems worldwide can now detect new subvariants faster and deploy targeted vaccines more effectively. They can treat infections with better success rates. The NB.1.8.1 sublineage spreads easily but hasn't made people sicker—a pattern that matches Omicron's development so far.

Notwithstanding that, some challenges persist. Vulnerable populations need resilient protection even though most people experience milder symptoms.

COVID-19's change from an unknown threat to a manageable respiratory illness stands as one of the most important public health achievements in recent years. This transformation resulted from a shared scientific effort, adaptive medical practices, and public cooperation.

1. Is COVID-19 still a concern in 2025?

   Yes, COVID-19 remains present in 2025, with varying levels of infection rates across different regions. While the situation has improved since the early days of the pandemic, ongoing monitoring and precautions are still necessary.

2. What is the current dominant COVID-19 variant?

   As of 2025, the NB.1.8.1 sublineage of the Omicron variant is the most prevalent strain. This variant maintains high transmissibility but has not shown increased severity compared to earlier Omicron versions.

3. How does the Omicron variant differ from previous strains?

   Omicron has approximately 50 mutations, with 32 in the spike protein. This gives it stronger binding to human cells, faster replication in airways, and a better ability to evade antibodies. However, it often causes milder symptoms, especially in individuals who are vaccinated.

4. What are the typical symptoms of Omicron in 2025?

   Common symptoms include nasal congestion, sore throat, and less frequent fever. Gastrointestinal symptoms have become more common in certain sublineages, while loss of smell or taste occurs in fewer cases.

5. How has the response to COVID-19 changed since Omicron's emergence?

   Since 2021, there's been a significant shift in both public perception and medical response. Improved vaccines, targeted treatments, and refined hospital protocols have transformed COVID-19 from a novel threat to a more manageable respiratory illness for most people, though vulnerable populations still require robust protection.