As the virus mutates, the most common COVID symptoms appear to be changing, too

SARS-CoV-2, the virus that causes COVID, is devastating precisely because it can worm its way into so many different organs and systems in the body. That manifests as different symptoms, from fever to trouble breathing, although an infection can be asymptomatic, too — that is, no symptoms at all.

Throughout the pandemic, there have been a few telltale signs of COVID infection. The loss of sense of smell and taste were chief among them. But as the virus has mutated again and again, creating new strains like Typhon (BQ.1) and Gryphon (XBB) which can evade some of our tools to fight it, it seem that the symptoms of COVID may have changed as well.

Recent estimates published by the Centers for Disease Control and Prevention on Friday pegged Typhon and its close relative Cerberus (BQ.1.1) as making up 27 percent of cases, an 11 percent increase from last week. Meanwhile, cases of BA.5, the strain that has dominated cases for the majority of summer, dipped below 50 percent for the first time in months.

Indeed, emerging data suggests the symptoms of COVID are changing with new variants. And, they can differ regardless of whether you’ve been vaccinated or not, or previously infected. Newly released data from the ZOE Health Study, which maintains the COVID Symptom Tracker app, finds that the dominant symptoms have shifted.

The app was originally launched in March 2020. It quickly logged one million users, who typed in how COVID was making them feel, allowing researchers to pin down some of the most common COVID symptoms. It was part of the reason why it became well-known that anosmia (loss of smell and taste) is a key symptom of the original COVID strain.

More recently, ZOE crunched the data from over 4.8 million users and found that after two vaccinations, the top-ranking symptoms were sore throat, runny nose, blocked nose, persistent cough, headache, in that order. (Vaccines can protect against severe disease, which generally means hospitalization or death, but breakthrough infections are not unheard of, although far less severe than infections in the unvaccinated.)

Just one dose of a vaccine can shift the order of most common symptoms to headache, runny nose, sore throat, sneezing and then persistent cough. For those who haven’t received a vaccine at all, the symptoms are generally closer to the original ranking from 2020: headache, sore throat, runny nose, fever and persistent cough.

However, loss of smell has slipped to the number nine slot, while shortness of breath is down at number 30 for this group. ZOE says this indicates “the symptoms as recorded previously are changing with the evolving variants of the virus.”

Just because SARS-2 appears to be evolving does not mean that it will become more “mild” — and it’s definitely nothing like the flu or a regular cold. The virus indiscriminately attacks the inner lining of blood vessels, causing injuries to the heart and lungs, and can cause literal brain damage. Given the broad range of debilitating symptoms known as long COVID, it doesn’t really make sense to call this “mild.” Additionally, repeat infections could have unknown consequences — experts aren’t entirely sure what happens when you get COVID two, three or more times.

That’s why watching out for new symptoms are so important. COVID may manifest differently because different viral strains sometimes impact different parts of the body. The delta strain, for example, found its niche in the lower respiratory tract, while omicron BA.2 tends to prefer the upper airway.

But it’s also critical to note that the data from ZOE is self-reported and doesn’t take into account demographic information or which variant caused the infection. It’s also using averages to report the most common symptoms — everyone is different and there is no guarantee here the disease will follow a certain course.

Nonetheless, the data gives a good idea of what to expect and people should be aware of these changes in order to best protect themselves. And the tools to fight COVID haven’t really changed: testing, masking, indoor ventilation, drugs like Paxlovid and, of course, the vaccines are all powerful strategies we should be using more to prevent this winter wave from becoming extremely deadly. The Biden Administration warned this week that an estimated 30–70,000 Americans could die from the virus this winter. But even a small wave could cause supply chain disruptions and sicken millions.

One thing that could make this winter worse than previous COVID waves is the rise of a “variant soup,” meaning multiple new strains of the virus surging at once. In previous fall and winter waves, only one type of the virus (i.e. delta or the original “wild type” strain) has really dominated.

Public health experts are also warning of a “twindemic” or even “tripledemic” in which COVID surges along with flu and respiratory syncytial virus (RSV). Most people may have never heard of RSV, but it was first discovered in chimpanzees in 1956, and the virus regularly causes outbreaks in humans. It’s usually only serious in babies and older people, but it’s still not a fun illness.

Even though the fall is just beginning, both flu and RSV are returning with a vengeance after relatively few cases the previous two years. On Friday, the Washington Post reported that this flu season is early and more severe than it has been in 13 years, “with at least 880,000 cases of influenza illness, 6,900 hospitalizations and 360 flu-related deaths nationally.” Meanwhile, pediatric hospital beds across the U.S. are filling up with RSV cases, many of them completely full for weeks.

Symptoms of flu and RSV may overlap (cold-like symptoms like fever, runny nose, coughing), making it somewhat confusing for sick people to know what illness they really have. That underscores the importance of testing for COVID and visiting a doctor when ill, if you have access to medical care. It also serves as a reminder to stay home when sick and mask up when possible.

Masking prevents the spread of all three of these viruses: flu, RSV and COVID. That’s one theory as to why the last two winters have been mostly free of diseases other than COVID, which has dominated due to its novelty and severe contagiousness. But as restrictions loosen, some of these more familiar viruses are coming roaring back. Keeping track of new and old symptoms is really only part of the equation. Masks, vaccines and social distancing continue to be some of the best tools at our disposal.