Covid-19: What Are Variant Of Concern (VOC)? Know Everything About These Variants

There are variants of concern, that are on top of WHO's list. Here's everything you need to know about them.

Navya Kharbanda
Written by: Navya KharbandaPublished at: Dec 06, 2021Updated at: Dec 08, 2021
Covid-19: What Are Variant Of Concern (VOC)? Know Everything About These Variants

All types of viruses, including SARS-CoV-2, the virus that causes COVID-19 can also grow and change over time. Usually, these minor changes might little to no impact on the virus’ features. But, there are some changes that can leave an impact on the virus’s properties, like how easily and quickly it spreads, the severity of symptoms, or the efficacy of vaccines, therapeutic medicines, diagnostic tools, or other public health and social measures. The mutations of Coronavirus can prove to be extremely harmful for public health worldwide. The entire world is trapped in the grasp of this deadly virus and countries have started implementing travelling instructions due to the severe and rapidly spreading new Omicron variant.

Do you know what is variant of concern (VOC)? During the late 2020, there was an emergence of variants that can pose a higher risk to public health worldwide, which made the global bodies make the classifications on the basis of characterisation of specific Variants of Interest (VOIs) and Variants of Concern (VOCs), in order to prioritise global monitoring and research, and ultimately to inform the ongoing response to the COVID-19 pandemic. WHO and the other International team of experts are observing all the changes of this virus so that if any amino acid substitutions are spotted, they can inform countries and the public about any changes that may be needed to respond to the variant, and prevent its spread. Read on to know more about VOC of Coronavirus.

What are Variants of concern (VOC)

A SARS-CoV-2 variant that can be classified as per the definition of a VOC and, after a complete comparative assessment, there are variants that can be demonstrated and associated along with one or more of the below listed changes as per the parameters of global public health significance: 

  • High transmissibility or detrimental change in COVID-19 epidemiology
  • A spike in virulence or change in clinical disease representation
  • Reduction in effectiveness of public health and social steps or available diagnostic tools, vaccinations, therapeutics.  

Variants of concern (VOC)

Variants of concern may require one or more proper public health measures, such as notifying the World Health Organisation or WHO under the International Health Regulations and reporting to the Central Disease Control or CDC. According to the current scenario, the variants of concern or VOC are mentioned below:

1. Delta (B.1.617.2 and AY lineages)


Increased transmissibility

  • Mostly all the lineages termed under Delta variant are suspects of Emergency Use Authorization (EUA) monoclonal antibody treatments. AY.1 and AY.2 lineages are not very susceptible to few monoclonal antibody treatments
  • Less neutralization by post-vaccination sera
  • Some severe symptoms



  • Runny nose
  • Headache
  • Sneezing
  • Fever
  • Persistent cough
  • Fatigue

2. Omicron (B.1.1.529)


  • Increased transmissibility than other variants
  • Less potential neutralization by some EUA monoclonal antibody treatments
  • Potential reduction in neutralization by post-vaccination sera


  • Dry cough
  • Scratchy thoat
  • Less or no fever
  • Minor muscle pain
  • Extreme fatigue

Therefore, variant of concern or VOC means the variants of emergence that can prove to be a higher risk than others, which includes Delta and omicron variant. On the global level, there are systems that have been established and are continuously  meeting to identify 'signals' of potential VOIs or VOCs and examine them in detail, based on the risk they can possess on global public health. If you are experiencing any symptoms of COVID-19, you should report it to your doctor. And, take appropriate precautionary measures to prevent Covid infection.