According to NPR, the coronavirus is mutating—but that’s probably not a reason to worry. Despite climbing numbers of infections and deaths, viral mutation happens all the time. Here’s why it isn’t a cause for concern.
The coronavirus appears to be changing its genetic makeup—news that may initially sound quite worrisome. However, this mutation is very unlikely to be a real source of trouble. “Inevitably, viruses ‘make mistakes in their genomes’ as they copy themselves,” the NPR article said. “Those mistakes can accumulate and carry over to future copies of the virus. So far, researchers who are tracking the genetic changes in SARS-CoV-2 say it seems relatively stable.”
The article goes on to say that the small changes in the virus’s genetic makeup don’t change its functions. This stability means that once a person gains immunity to the strains of the virus in circulation, their immune system will be protected for a longer time—potentially years—should it continue to circulate. Mutations are par for the course in the world of virus replication.
How Viruses Replicate
“Viruses are life forms whose genetic material—either DNA or RNA—replicates inside living cells using the cells’ own synthetic machinery,” said Dr. Barry Fox, Clinical Professor of Infectious Disease at the University of Wisconsin School of Medicine and Public Health. “This leads to the synthesis of components of the virus that are subsequently reassembled, and then transferred to other living host cells, or sometimes to the environment.”
Although they replicate, viruses are entirely dependent on their hosts for survival. SARS-CoV-2 is an RNA (ribonucleic acid) virus, so Dr. Fox said it has to trick the host cells into producing an RNA polymerase. An RNA polymerase is an enzyme that essentially causes a DNA sequence to copy into an RNA sequence. Then the RNA virus can be replicated.
“After the virus’s DNA or RNA replicates in a host cell, it directs the cell to help the virus package itself in the cytoplasm, and then the virus breaks free from the host cell into a neighboring cell, or sometimes into the bloodstream,” Dr. Fox said.
Once a virus has left one cell, that cell will either die completely or remain alive and partially function. Viruses replicate exponentially and very rapidly, hence the occasional “mistake” that leads to mutation.
Social Distancing and Warm Weather
Social distancing has been widely advised for combating the spread of coronavirus. The reasons for staying isolated during a viral outbreak may seem obvious, but they go beyond trying to avoid having someone cough on you.
“Sneezing and coughing are an easy way for germs to spread, but larger droplets settle quickly from the air and are not contagious,” Dr. Fox said. “Viruses are more likely to spread via wet secretions that contaminate surfaces in the environment, such as respiratory childhood viruses. Many viruses can survive up to four days on solid surfaces.”
This is part of why virus transmission often happens in the winter. According to Dr. Fox, we congregate closer together in wintertime, increasing the likelihood of spread. In terms of the weather, lower humidity and lower temperatures enhance the virus’s survival. While that doesn’t mean viruses can’t live in warm weather, winter weather goes a bit easier on them.
Dr. Barry Fox contributed to this article. Dr. Fox is a Clinical Professor of Infectious Disease at the University of Wisconsin School of Medicine and Public Health. He received his undergraduate degree in Molecular Biophysics and Biochemistry from Yale University and his medical degree from Vanderbilt University.