How Do Viruses Mutate and What Does It Mean?

How Do Viruses Mutate and What Does It Mean?

Virus mutations are common and natural. But will a stronger COVID-19 variant than omicron appear? Learn about virus mutations and what employers need to know.
Contributors
Lisa Chirch
Lisa Chirch, Associate Professor of Medicine and Fellowship Director for Infectious Diseases, UCONN Health
Adam L. Seidner, Chief Medical Officer, The Hartford
Adam L. Seidner, Chief Medical Officer, The Hartford
As the world continues to deal with COVID-19 and the omicron variant, unknowns still remain around the possible discovery of a new, stronger variant that could lengthen the pandemic and further fuel pandemic fatigue.
 
After dealing with the original SARS-CoV-2 viral strain that caused the COVID-19 illness, the delta variant caused spikes in infection rates. And at the end of 2021, it took just a few weeks for the omicron variant to overtake delta and become the new dominant strain. Identified as more infectious than delta, omicron was responsible for another surge in positive cases.
 
Now, a few months after omicron’s discovery, officials are monitoring a new sub-variant of omicron that could make the virus harder to detect. Omicron BA.2, which researchers are calling the “stealth variant,” was found in 74 countries, including the U.S.1
 
The recent news of BA.2 can make people worry with new questions arising. How long will the COVID-19 virus mutate? And if it continues, will a new variant cause more infections and severe illness?
 
Dr. Adam L. Seidner, chief medical officer at The Hartford, said he believes we’ll go from a pandemic to an endemic phase punctuated by epidemic phases. However, he said that COVID-19 will be something the world has to live with – similar to the flu.
 
“We’ll have seasonality, where if you’re in closer quarters and inside more, you’ll see more cases of it,” Seidner explained. “So, cases will increase in the winter months, but taper off in the warmer seasons.”
 

Why Do Viruses Mutate and What’s Happening?

Mutations occur as viruses replicate within a human or host. It’s a process that happens as part of natural selection, according to Dr. Lisa Chirch, associate professor of medicine and fellowship director for Infectious Diseases at UCONN Health. Chirch explained that viruses mutate to survive, so they may evolve in ways that make them more difficult to detect, prevent, or treat.
 
“Some mutations occur randomly, but others are advantageous from a survival standpoint,” Chirch explained. “These are typically the more dangerous mutations that allow the virus to spread more easily within a community.”
 
Errors in the replication process cause mutations. A mutated virus is also known as a variant. You can think of variants as strains that are different in some ways, but similar to the original strain.
 
These changes can have an impact on how severe an illness might be or how infectious the strain is. The human body’s immune system uses the antigens on the surface of a virus to identify it. If there are mutations in the viral strain, it makes it harder for the immune system to identify and fight it.
 

How Do New Variants of COVID-19 Occur?

New variants of COVID-19 occur as the coronavirus strain mutates within a person’s body. According to the U.S. Centers for Disease Control and Prevention, variants are expected.2 The global health community has gotten very good at genomic tracking, so it’s not unlikely that new variants will be discovered, Chirch added.
 
“If we look, we’re going to find them,” she noted. “So, we have to be thoughtful and careful in how we consider new variants and their potential impact.”
 
Although many variants may emerge, not all will cause severe illness or show increased transmissibility. This is why the World Health Organization (WHO) monitors variants and labels certain isolates as:
 
  • Variants of Concern (VOCs)
  • Variants of Interest (VOIs)
  • Variants Under Monitoring (VUMs)
As of March 3, 2022, the WHO classified five variants as VOCs:
 
  1. Alpha
  2. Beta
  3. Gamma
  4. Delta
  5. Omicron

A Look at the Omicron Variant

The omicron variant has at least 50 mutations from the initial SARS-CoV-2 strain.3 Most of these mutations are in the protein spike of the virus, which affects its transmissibility.4 It’s the reason why the omicron variant is so contagious. Because of these differences, it makes it harder for a person’s antibodies to identify and fight the virus. This leads to more infections and even re-infection.
 

BA.2: A Sub-Variant of Omicron

Researchers are monitoring a sub-variant of omicron, known as BA.2. Deemed the “stealth variant” because it can be harder to detect on tests, the BA.2 sub-variant started to become the dominant strain in Denmark and South Africa.5
 
While it’s unclear if BA.2 will cause severe illness, officials from the WHO recently stated that it has the potential to replace omicron as the dominant strain globally.6 In fact, in February, the WHO stated the BA.2 sublineage should be considered a variant of concern given available data on:7
 
  • Transmission
  • Severity
  • Reinfection
  • Diagnostics
  • Therapeutics

COVID-19 and Viral Shedding

Viral shedding refers to the process of a person infected with a viral infection spreading particles. How long a person sheds the COVID-19 virus remains a relevant question to this day. It seems like the answer to this question depends on the variant.
 
Early in the pandemic, a study showed people spread “high amounts” of the virus early on in their infection.8 The same study found people with mild symptoms were no longer infectious 10 days after their symptoms.9
 
A recent study in Japan, however, found people infected with the omicron variant shed the virus for longer after exhibiting symptoms.10
 

Reproduction Number (R0) of the Omicron Variant

When trying to determine how quickly an infection can spread in an outbreak, researchers use its reproduction number. Also known as R-naught (R0), it shows the average number of people that one infected person can pass the illness to.
 
For example, the flu has a R0 of 1. So, an infected person would get one other person sick.
 
Each surge has been secondary to a variant of COVID-19 that is more contagious as the R0 has increased, Seidner said.
 
The original strain of COVID-19 had a R0 value of 2 and the Alpha or U.K. variant had a R0 of 5.11 The delta variant had a R0 value of nearly 7.12 The omicron variant’s R0 value could be as high as 10.13 It puts the omicron variant’s infectiousness at a similar level to chicken pox.
 
“It’s surprising and staggering how quickly a new variant emerges,” Seidner said.
 

Do Vaccines Help Protect Against COVID-19 Variants?

Both Seidner and Chirch said vaccines can protect people from getting a severe illness from COVID-19 and lower the risk of spreading infection.
 
“If an unvaccinated person gets sick, they’ll have a higher viral load and have a greater possibility of infecting more people,” he explained. “When you’re vaccinated, it means you have less virus shedding. All in all, you’ll be less of a public risk hazard.”
 
Chirch added that it’s not just the person getting vaccinated who is protected, but also the people around them. While talking with her patients about the vaccine, Chirch said she’s honest about her perspective and explains the risks versus benefits.
 
“I tell them what I think, what my experience has been and why I think it’s the right thing to do – not just for my patient, but also for anybody that they care about,” Chirch explained. “There will likely be people around them that are at higher risk, like small children who can’t yet get vaccinated or loved ones who are immunocompromised. It’s not just about you. It’s about them, too.”
 
While people who survive a COVID-19 infection have natural immunity for a period of time, both Seidner and Chirch stressed the dangers with purposefully getting infected. There’s a risk with experiencing symptoms even after recovering from illness – a phenomenon called “long-COVID” – as well as potential permanent heart and lung disease, Seidner said.
 
“That’s playing with fire,” Chirch added. “It doesn’t matter how young and healthy you are, COVID-19 is unpredictable and you can become gravely ill. And again, one should consider the impact on others – it’s not just dangerous for the individual, but it’s dangerous for anyone they come in contact with.”
 

'Universal Source Control' To Help Employers Protect Against Viral Outbreaks

The pandemic will eventually reach an endemic stage where COVID-19 doesn’t fully go away. It will be something the world will have to deal with on a regular basis – similar to the flu, according to Seidner. Because of this, he believes employers need to take general precautions to protect workers and keep them safe. It’s a principle that he calls “universal source control.”
 
“You treat everyone as a potential source and you have policies and procedures in place that address that,” Seidner explained. “If you’re sick, don’t come to work. Employers may need to implement other measures, like physical barriers, masking, social distancing, screening and testing.”
 
In addition, Seidner emphasized the importance of maintaining the HVAC systems along with cleaning and sanitization in the office.
 
 
 
1, 5 Newsweek, “BA.2 ‘Stealth’ Omicron Variant Now in 74 Countries, Dominant in at Least 2”
 
2 U.S. Centers for Disease Control and Prevention, “What You Need To Know About Variants”
 
3 American Society for Microbiology, “How Ominous Is the Omicron Variant (B.1.1.529)?”
 
4 UC Davis Health, “Omicron Variant: What We Know So Far About This COVID-19 Strain”
 
6 Reuters, “Omicron Subvariant BA.2 Likely To Have Same Severity As ‘Original’ – WHO”
 
7 World Health Organization, “Statement on Omicron Sublineage BA.2”
 
8, 9 STAT, “People ‘Shed’ High Levels of Coronavirus, Study Finds, But Most Are Likely Not Infectious After Recovery Begins”
 
10 The BMJ, “COVID-19: Peak of Viral Shedding Is Later With Omicron Variant, Japanese Data Suggests”
 
11, 12, 13 The Lancet, “Omicron Variant and Booster COVID-19 Vaccines”
 
The information provided in these materials is intended to be general and advisory in nature. It shall not be considered legal advice. The Hartford does not warrant that the implementation of any view or recommendation contained herein will: (i) result in the elimination of any unsafe conditions at your business locations or with respect to your business operations; or (ii) will be an appropriate legal or business practice. The Hartford assumes no responsibility for the control or correction of hazards or legal compliance with respect to your business practices, and the views and recommendations contained herein shall not constitute our undertaking, on your behalf or for the benefit of others, to determine or warrant that your business premises, locations or operations are safe or healthful, or are in compliance with any law, rule or regulation. Readers seeking to resolve specific safety, legal or business issues or concerns related to the information provided in these materials should consult their safety consultant, attorney or business advisors. All information and representations herein are as of March 2022.
The Hartford Staff
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