With winter underway and cases of Omicron surging nationwide, you may be wondering if that runny nose or aching throat is a dreaded case of COVID-19 that’s finally tracked you down, or if it’s merely a symptom of the common cold.
On top of that, the flu virus, which had all but vanished last year as the pandemic gripped the nation, appears to be making a comeback, according to the latest data from the Centers for Disease Control and Prevention.
Distinguishing between it all can be hard, and finding a COVID-19 test can be harder. Here we try to break down what we know about Omicron symptoms so far (remember, much is unknown this early in the outbreak) and how they may differ from the common cold and flu, or even from the previous variant, Delta.
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What does early data tell us about Omicron?
Omicron is now the dominant variant in the country and is spreading at a rapid rate, with cases rising about 23 percent in the past two weeks or so alone, according to data from the CDC. The variant has an unusually high number of mutations, some of which may be enabling it to evade immune protection. And early data has demonstrated that it is about two to three times more transmissible than the Delta variant. As a result, many, including those who are vaccinated, are likely to test positive for the virus.
Because the variant is a relatively new discovery, scientists are still studying the severity of illness and what symptoms it will bring — and if they vary from other strains. Some hopeful news arrived this week, with three teams of scientists, who studied the course Omicron took in South Africa, Scotland, and England, releasing preliminary results that showed infections more often resulted in mild illness compared to those from the Delta variant before it. The findings suggested those infected were less likely to be hospitalized, but there were caveats.
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How are Omicron symptoms similar to Delta or other variants?
Preliminary reports indicate that those infected with the variant generally display similar symptoms to those who have been infected with either Delta or the original coronavirus.
Data scientists with the health company ZOE used the most recent data from London, where the prevalence of Omicron is higher than in other regions throughout the United Kingdom, to analyze symptom data and compare it with data recorded in early October when Delta was dominant. The analysis found no clear difference between the two — and only about half of people experienced the “the classic three symptoms of fever, cough, or loss of sense of smell or taste.” The top five recorded symptoms in both periods were a runny nose, headache, fatigue, sneezing, and sore throat. They tended to be “mostly mild” and “cold-like.”
Here in the United States, possible symptoms of the coronavirus listed by the CDC include fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, the new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea.
How might Omicron symptoms differ from Delta or other variants?
When Delta became the dominant variant and led to an uptick in cases, cold-like symptoms became more common, as the lead scientist on the ZOE COVID Study app noted last week. It appears to be the same case with Omicron, and some of the key symptoms first seen earlier in the pandemic — namely a loss of taste and smell — are not as typical.
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An analysis published by researchers in Norway following a small Omicron outbreak among “fully vaccinated” people found that only 23 percent of patients reported a loss of taste, and only 12 percent reported a loss of smell. Meanwhile, a runny or stuffy nose, fatigue, cough, and a sore throat were the most common symptoms.
Early evidence also suggests that Omicron is less likely to spread deep into the lung tissue, despite it replicating in the upper airway quickly, which could help to explain why infections may appear milder. A study undertaken by Hong Kong University researchers found that replication of the variant in deeper lung tissue was more than 10 times lower than the original strain of the virus.
It should also be noted that, according to data collected by ZOE, the symptoms one experiences can vary depending on vaccination status.
What about the common cold or flu?
Both the flu and the common cold are contagious respiratory illnesses that share similar symptoms despite being caused by different viruses, according to the CDC. In general, flu symptoms are more intense and begin more abruptly, while colds are usually milder and do not typically result in serious health problems.
The symptoms of the flu, according to the health protection agency, can include muscle or body aches and “fever or feeling feverish/chills.” It can have associated complications. Meanwhile, people who have a cold tend to have a runny or stuffy nose.
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Compared to the flu, COVID-19 can cause more serious illnesses in some people, according to the CDC. It can also take longer for people to experience symptoms and they can be contagious for a greater period of time.
The CDC also stressed that because some of the symptoms of both the flu, the coronavirus, and other respiratory illnesses are so similar, testing is required to “tell what the illness is and to confirm a diagnosis,” especially because people can be infected with both the flu and COVID-19 at the same time.
Still looking for answers and have places to be?
In short, for those looking to determine what they are sick with for travel or planning purposes, public health experts recommend getting tested for the coronavirus beforehand.
Read Next
- While COVID cases soar in Massachusetts, new Omicron data offers promise
- PCR or rapid antigen? Here’s how to use COVID tests to gather safely for the holidays
- Found yourself in quarantine? We asked public health experts for suggestions on how to spend the time
- Leaders of 9 Massachusetts hospitals ask the public to do 5 things to help control COVID-19 surge
Shannon Larson can be reached at shannon.larson@globe.com. Follow her on Twitter @shannonlarson98.