It would be nice if Covid-19 disappeared before the flu and cold season hit us. Unfortunately, all three virus-caused conditions will likely be with us at once.

And that will put a dose of anxiety into every sneeze. How can we know if it’s trivial winter sniffles or something more serious?

ISRAEL21c asked Israeli experts how to make an educated guess.

They say that while some symptoms are unique to each malady, others can be common to all three and the only way to rule out Covid is to get tested.

Tell-tale symptoms

Rivka Abulafia-Lapid, a PhD lecturer in virology and immunology at Jerusalem’s Hebrew University-Hadassah Medical School and its affiliated nursing school, starts by identifying unique early signs of Covid-19, the disease caused by the SARS-CoV-2 coronavirus.

“The most important symptoms of Covid-19 are shortness of breath and loss of smell,” she says.

These two tell-tale symptoms don’t show up in flu or the common cold.

A dry cough is another symptom often accompanying Covid-19, but not a runny or stuffy nose. If you’re blowing your nose, it’s probably a cold.

Rivka Abulafia-Lapid, a lecturer in virology and immunology at Jerusalem’s Hebrew University-Hadassah Medical School. Photo: courtesy

Although both colds and Covid are caused by members of the coronavirus family, people with Covid-19 may get sicker because SARS-CoV-2 is new to the immune system, Abulafia-Lapid says.

As for influenza, early signs are different: headache, body aches, fever, chills, sore throat and loss of appetite. Children may get a middle-ear infection and stomach upset too.

And now for the confusing part.

Like the flu, Covid-19 can cause a fever. Like Covid-19, a cold can cause a dry cough. And it is possible for flu to progress into pneumonia, triggering upper respiratory symptoms just like Covid-19.

“Everyone is different, and it all depends on how your immune system reacts,” says Abulafia-Lapid.

She recommends getting tested ASAP if you have common Covid-19 symptoms because unlike the flu it infects more types of cells and can move from the lungs to attack the kidneys, soft body tissues and even the brain or heart.

Her main advice is to try avoiding infection altogether by wearing a facemask over your mouth and nose, keeping your distance from other people and frequently washing and disinfecting your hands. And this: “Don’t panic.”

Possible surprises

“Many infectious diseases change and surprise us,” says Dr. Manfred Green, director of the University of Haifa’s international master’s program in public health, previously head of the Public Health Branch of the IDF, and founding director of the Israel Center for Disease Control.

Surprises can be good or bad.

A possible bad surprise is that Covid-19 will be around for a year or more before we have an effective vaccine.

A possible good surprise is that infection rates will decline more quickly than expected. Although viruses don’t disappear, Green explains, they do wane.

“Obviously, there are things we still don’t understand. We don’t really understand why seasonal flu epidemics tend to end after two months,” Green tells ISRAEL21c.

Dr. Manfred Green, director of the University of Haifa’s international master’s program in public health and founding director of the Israel Center for Disease Control. Photo: courtesy

Before the flu season begins, Green says that even symptoms that look like flu could indicate Covid-19.

“Right now, if you have a sore throat and fever – typical signs of influenza — there’s a high chance it’s Covid because we don’t usually see that at this time of year,” he explains.

“In winter, it will be much more problematic [to tell them apart].”

However, another good surprise may be a mild flu season, says Green – though he cautions that this is only a prediction and should not keep people from getting a flu vaccination.

“Influenza moves between the northern and southern hemispheres. There’s been virtually no flu in the southern hemisphere during their winter this year,” he notes.

Furthermore, flu is much easier to prevent than Covid. “Masking and social distancing is probably very effective in preventing flu. And if the same percentage of people gets vaccinated, about 25% as in the past, we’ll probably have very little influenza this winter.”

Everyone is different

Like Abulafia-Lapid, Green stresses that individual reactions differ and there’s a spectrum of symptoms – making it difficult to rule out one viral infection over another.

“Although there are differences in clinical signs early on, they can be quite subtle,” Green says. “If you have a runny nose and no fever, it’s probably a cold and not influenza, but it still could be.”

Innovation is what will help us most with this dilemma, he says.

“Rapid tests will change the game. If we can test someone in 10 minutes and rule out Covid – even though some cases will be missed by false negatives — it will make things easier at work and school.”

He believes such tests will be available quite soon. (Click here to read about Israeli testing solutions under development.)

“Once we have rapid tests, if someone has mild symptoms and tests negative, you can feel comfortable that it’s probably not Covid.”

Meanwhile, anyone with sniffles — and certainly with fever and a sore throat — should stay home, Green advises.

To avoid masses of people having to enter isolation because of a work colleague or classmate feeling ill, Green encourages everyone to keep a safe distance from one another and wear a facemask.

Watch for our next article with expert tips on how to prevent getting ill this winter.