Woman in lab using a microscope to research coronavirus variants

More COVID-19 questions: What about mutations and asymptomatic spread?

Mar 01, 2021 COVID-19 Share:

Over the past year, we’ve learned how to cope with COVID-19 spreading in our communities. Everyone knows what actions to take to prevent the spread of COVID-19, what symptoms to look for, and how to get a test if they need one. We’ve learned how to safely keep our kids in schools, and we’re even seeing the early stages of vaccine distribution.

But with COVID still circulating, we're finding that many of our patients still have questions. Last week, we explored questions about testing, follow-up, and quarantine measures. This week, we're answering questions about coronavirus variants and asymptomatic spread.

Should I be concerned about the new strain of COVID that they’re reporting? Is it really more contagious or dangerous?

You’ve probably heard about the new coronavirus variants circulating in our communities. At the time of publication, there are multiple coronavirus variants (or mutations) that are circulating in the United States. While these variants are certainly making the news, there’s no need to panic.

Viruses mutate. This is not unusual or unique to COVID-19. For example, the flu virus that begins to circulate in September of each year is never the same virus that circulated in March. This is why you need to get a new flu shot every year.

Virus mutations can happen over a relatively short period of time. No scientists were surprised that COVID-19 mutated. When coronavirus emerged, it was never a question of if it would mutate; it was a question of when. In fact, coronavirus will continue to mutate as it spreads.

You may have heard that these new mutations or variants spread more easily and more quickly than other variants of COVID-19. While this may be true, this doesn’t mean you need to be afraid. Preventative measures such as social distancing, frequent handwashing, and masking will provide protection from any COVID-19 variant. Preliminary research also shows that coronavirus vaccines also provide protection from these variants.1

How your immune system fights virus mutations

Your immune system has a sophisticated system for fighting off infections. When you have developed antibodies for a virus, neutralizing antibodies recognize the virus as an invader and work quickly to fight it off. These neutralizing antibodies work like security guards at a party. They recognize the virus as unwelcome, and they send it on its way before it can cause any trouble.

When a virus mutates, it’s more difficult for the neutralizing antibodies to recognize the virus as an invader. Scientists are finding that these mutations are bypassing the neutralizing antibodies, but not the cellular immunity. Cellular immunity is a form of adaptive immunity that is achieved through previous infection or vaccination.

Even if you have had COVID-19, you can be infected with a mutation or variant. However, your adaptive immunity will attack the virus before it can do much damage. The security guards may not recognize the virus at the door, so the virus can infect your cells. But your adaptive immune system will quickly recognize the intruding virus and kick it out. You may experience some symptoms of coronavirus, but they will be mild and short-lived.

One of the reasons COVID-19 has been so deadly is that it is a novel coronavirus. This means that no version of this virus has ever been seen before. Your immune system is unprepared to fight off a novel virus. If you’ve never been infected with COVID-19, any mutation will also be novel. But if you have antibodies from a previous coronavirus infection or from a coronavirus vaccine, your immune system will be prepared to fight off any coronavirus variants that are circulating now or in the future.

How concerned should I be about the asymptomatic spread of COVID-19?

Before we discuss asymptomatic spread, it’s important to understand exactly what asymptomatic spread is. Asymptomatic virus transmission is the transmission that occurs from individuals that test positive for COVID-19 but never develop symptoms of the virus.

In the early months of the pandemic, we were very fearful of asymptomatic viral transmission. The good news is that asymptomatic transmission is both uncommon and unusual. However, it is possible to transmit COVID-19 without any symptoms of the virus, but this usually occurs in the period prior to symptom-onset. This is known as presymptomatic transmission.

Presymptomatic transmission can occur up to 48 hours prior to the onset of COVID symptoms. This means that people can transmit the virus to other people when they do not have any symptoms, but these people almost always eventually develop symptoms. Presymptomatic spread most often happens in households and with the people you have extended close contact with, not out in the community (like at the grocery store).

Individuals who don’t yet have any symptoms of coronavirus may be more likely to spread the virus than those who do have symptoms. Most people who develop symptoms of COVID-19 will quarantine and limit their social contacts.

If you’ve had close contact with someone who tests positive for COVID-19 within 48 hours of the onset of their symptoms or a positive test, you should monitor yourself for symptoms. Symptoms of COVID-19 include fever or chills, cough, shortness of breath, fatigue, new loss of taste or smell, sore throat, and congestion, or a runny nose.

If you do develop symptoms after a known exposure, you should get tested right away. There’s no need to get tested before symptoms develop. In fact, testing too early or before the onset of symptoms can lead to a false-negative result in a rapid antigen test.

News about COVID-19 can be frightening and confusing, and it’s perfectly normal to have questions about the virus. At MedHelp, we’re here for you whenever you have questions about your health. Established patients are always welcome to contact their primary care doctor with any questions they may have about COVID-19 or other health concerns.

We're here for you.

Whether you need a test for COVID-19 or have another urgent care need, our clinics are open seven days a week with extended weekday hours.


1About variants of the virus that causes COVID-19. https://www.cdc.gov/coronavirus/2019-ncov/transmission/variant.html. Last updated February 12, 2021. Accessed February 21, 2021.


At MedHelp, it is our intent to prevent timely and relevant information and guidance for our patients. Covid-19 is rapidly evolving, and articles published more than two months ago may not reflect the most up-to-date information about this illness. Please check our most recent articles for more current information.