Advance with MUSC Health

COVID-19 Continues On: The Omicron Variant

Joseph Gerald (Jerry) Reves, M.D.
January 18, 2022
Illustration of Coronavirus

We begin this year with Omicron, the newest variant of COVID-19 that is infecting millions of people across the United States and the world. The news is good and bad as we watch South Carolina’s infections peak at unprecedented levels as of this writing – that’s the bad news. The good news is that in other countries the rapid rise in cases appears to be followed by just as rapid a decline in the spread.

The Omicron variant of COVID-19 has more than 50 mutations than the original SARS-CoV-2 virus. This is what happens when a virus spreads around the world and through millions of individuals. Each time the virus lives in a new host it can change (mutate) and become more or less contagious.

The Omicron variant is far more transmissible (contagious) than its kinfolk. In fact, Omicron is thought to be five times as infectious as its cousin, the Delta variant. This explains the very rapid rise in infections depicted in the graph of recent South Carolina infections (See Figure 1).

Much is unknown about this variant, which is now the primary COVID-19 variant worldwide. However, early indications are that it is less virulent. This means illness caused by Omicron is less severe than previous variants, but hospitals are filling up, and so are their ICUs. The vaccines do appear to protect against serious illness and death from Omicron and other COVID-19 variants.

Omicron’s enhanced spread appears to be due partly to the fact that it seems to reside more in the upper airway (nose and throat) than in the lungs. This makes it easier to spread, but importantly means it’s less likely to cause pneumonia and serious breathing problems.

Omicron symptoms are like those of other COVID-19 variants, including fever, nasal congestion, cough, fatigue, muscle aches, lethargy, headache, loss of smell, and sore throat. Unfortunately, these are also the symptoms of influenza, so the two are difficult to differentiate without a tested. If you have these symptoms, get tested so that, if your results are positive, you can quarantine for the
recommended number of days.

The graph in Figure 1 shows that Omicron has spread rapidly and widely in South Carolina. In Charleston Country the spread has not been quite so fast as in some other parts of the state, but the case rate is much higher than ever before. Whereas 54% of the people in the state are fully vaccinated, Charleston County’s rate is 62%. The goal for vaccination is 100%.

The smaller tables in the figure show the results of the spread, including increases in positive tests, hospitalizations, and, to a lesser extent, deaths.

Everyone should avoid contracting Omicron. You know what to do, right? Avoid people whose health status is unknown to you. Wear a mask at all indoor public places. Avoid indoor events with large groups of people. Wash hands frequently. Avoid anyone who has symptoms or a positive COVID test and practice distancing when around anyone who has any infectious condition.

One worrisome aspect of Omicron is that it appears to “evade vaccine-derived immunity.” This is a scientific way of saying that both vaccines and natural immunity are not as effective at blocking the spread of Omicron as they are against other variants.

This results in a fairly large number of “break-through infections,” or infections in fully vaccinated and boosted individuals. The mutations have allowed Omicron to escape destruction by antibodies created with the vaccine and from the normal antibody response to the virus from infection with earlier variants (natural immunity).

However, evidence shows that the vaccines do protect against death and serious illness (hospitalization) in Omicron patients. Thus, the recommendations still hold that every individual eligible should get vaccinated and boosted. (See Table 1.) The booster does just what it sounds like: It keeps the immune response primed for the next attack.

The optimist in me hopes that the virus will evolve toward more infections that are milder and of shorter duration. If this occurs, we may be looking at a time, perhaps this year, when the pandemic burns out, having rapidly infected so many that there are not enough susceptible people left to infect.

In the meantime, we must be as vigilant as possible. Despite how tired we are of this pandemic, we must do everything we can to protect ourselves with vaccines, boosters, and all the other measures. This is not the time to ignore this virus, which remains potentially dangerous to us, the aged, who are the most vulnerable.


Graphic depicting State of South Carolina New Reported COVID-19 Cases and related data on administered tests, patients hospitalized and deaths. From: accessed January 12, 2022 
Figure 1. State of South Carolina New Reported COVID-19 Cases and related data on administered tests, patients hospitalized and deaths. From: accessed January 12, 2022