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Can the Coronavirus mutate?

Medically reviewed by Leigh Ann Anderson, PharmD Last updated on Mar 31, 2020.

Official Answer


Knowing that a mutation has occurred during a viral pandemic might set off a panic alarm in your brain. Just the word “mutation” itself is horrific and conjures up thoughts of monster movies. Even more disturbing is knowing that a virus replicates right inside your very own cells.

So, you might be wondering, can the coronavirus that causes COVID-19 disease mutate? And how will this affect ongoing vaccine development? Coronavirus is an RNA virus, similar to the flu and measles, but different.

Coronaviruses, like all viruses, can mutate, which leads to changes in their internal generic code. Experts say yes, the coronavirus (SARS-CoV-2) has mutated, albeit slowly.

However, not all viral mutations are dangerous or harmful. Some mutations may not affect the overall transmission of the virus or disease outcome. Mutations are an expected part of the virus life-cycle.

It is still up for debate whether or not major mutations will affect the coronavirus, and how this might affect vaccine development. But for now, mutations in SARS-CoV-2 appear to be happening very slowly.

“There is no credible evidence of a change in the biology of the virus either for better or worse” states Marc Lipsitch, a researcher from Harvard University, as reported by NPR. Coronavirus appears to mutate roughly one-third to one-half the rate of the influenza virus, or about 2 mutations per month. Coronavirus also appear to splice out their own mutations that don’t match up, leading to a more intact genome.

One early study from Wuhan, China and published in the journal National Science Review suggested mutations had led to two different strains of SARS-CoV-2, one more harmful than the other. However, epidemiologists from Yale School of Public Health state that due to the small study size and the small number of mutations found in the SARS-CoV-2 virus, it is not valid to attribute these changes to different strains leading to an impact on disease. Other scientists agree.

How do mutations affect vaccines?

Mutations can make vaccines hard to develop because of the change of the genetic footprint of the virus. Viruses often naturally mutate.

One example is the flu vaccine. New strains of influenza often appear worldwide each year, and those strains are incorporated into a new vaccine each flu season. Because the influenza vaccine gets a reboot each year, and it’s protective effect wanes over time, you need a yearly vaccine for protection against influenza.

But other viruses do not mutate so quickly. For example, the measles is slow to mutate. To protect yourself or your child from measles, one set of shots, typically given in childhood, is protective for a lifetime.

The coronavirus is a long virus microscopically-speaking, about 30,000 nucleotides long and twice the size of the flu virus. Researchers seem to think that the coronavirus is more similar to the measles virus, where mutations occur slowly. If this turns out to be true, you might only need one shot, or maybe a shot and booster, to be fully covered for coronavirus protection. These specifics are still under rapid investigation.

There is always the possibility that the SARS-CoV-2 could mutate over time, which might require an update to a new vaccine down the road. Human protection from the injection could wane, as well, and a booster shot might be required. Scientists are keeping a close eye on possible coronavirus mutations, which will help to steer vaccine development.

Currently, the coronavirus is doing just fine on it’s own; it’s potent and able to spread worldwide, meaning mutations are not required for its survival, according to Justin Bahl, an evolutionary biologist at the University of Georgia.

When will a coronavirus (SARS-CoV-2) vaccine be available?

Researchers believe it will take at least 12 to 18 months to get a vaccine developed and ready for use. Some estimates have suggested a vaccine could be ready by spring of 2021.

Even though 12 to 18 months seems like a long period of time, experts state it would be a record amount of time to have a vaccine available this quickly. Most vaccines take about 10 years to develop, test and get to market. Vaccine development for COVID-19 has been on the fast tracks thanks in part due to previous work done on other coronavirus outbreaks around the world.

Over 40 investigational vaccines are under study, using different methods of vaccine development. Moderna is working on a vaccine using messenger RNA (mRNA), a new technique never used before in a marketed vaccine. The vaccine is currently known as mRNA-1273. mRNA, which comes from DNA, is a short-term set of instructions that tells a cell how to make a protein. Proteins are one of the main building blocks of life.

According to Moderna, a major player in vaccine development, a COVID-19 vaccine could be available as early as the fall of 2020 for certain high-risk groups including health care providers. They are scaling production with the goal of creating millions of doses per month. The first participant received a dose of this vaccine in mid-March in an open-label Phase I study at Kaiser Permanente Washington Health Research Institute (KPWHRI) in Seattle.

There are also the possibility of setbacks to the coronavirus vaccine, such as:

  • Vaccines in development may not prove to be safe or effective in humans.
  • Coronavirus vaccine manufacturing may have delays due to limited facilities, personnel or funding.
  • The vaccine, when available, may be rolled out in phases to protect those at higher risk, such as health care workers, the elderly, people with chronic health conditions such as lung or heart disease, and pregnant women.
  • Viruses can adapt and develop resistance to vaccines, but experts state this is unlikely for coronavirus. For example, other RNA viruses, like the measles, mumps and yellow fever, did not develop resistance.

Bottom Line

The coronavirus (SARS-CoV-2) appears to be mutating slowly, which means that an eventual vaccine might be effective over the longer-term -- possibly years -- instead of requiring a vaccine every 12 months, as with the flu.

Not all mutations within a virus are harmful, and some viruses can adapt to remove errors within their own genomes, which lends stability. But some new coronavirus strains could emerge.

Vaccine research for SARS-CoV-2 is occurring at a fast pace and experts state a vaccine for general use could be available by spring of 2021.

  1. Tang X et al. On the origin and continuing evolution of SARS-CoV-2. National Science Review. Accessed March 30, 2020 at
  2. Saplakoglu Y. How fast can the coronavirus mutate? Live Science. Accessed March 30, 2020 at
  3. Huang P. The coronavirus is mutating. But that may not be a problem for humans. Goats and Soda. National Public Radio (NPR). Accessed March 30, 2020 at

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