More than six years after the COVID-19 pandemic began, physicians are still learning new things about how the virus affects the human body. While many of the early symptoms of COVID-19 are well known—fever, cough, fatigue, and the once-common loss of smell and taste—doctors are now observing a somewhat unusual new complaint among patients infected with recent variants of the virus.

The symptom that is being widely reported is an extremely painful sore throat, sometimes described by patients as feeling like “razor blades in the throat.” In some cases, individuals say the pain appears suddenly and is far more severe than the typical sore throat associated with a common cold.

Physicians in clinics and urgent care centers across the country have noticed the pattern. Patients often come in complaining primarily of severe throat pain. Initially, both the patient and the doctor may suspect strep throat or another bacterial infection. However, when tests are performed, the strep test is negative, while a COVID-19 test comes back positive.

This symptom appears to be associated with some of the newer descendants of the Omicron variant of the coronavirus. These newer strains tend to infect the upper respiratory tract—particularly the nose and throat—rather than deeply affecting the lungs as the earliest strains of the virus did.

Because of this shift, COVID-19 today often resembles a bad cold or upper-respiratory infection more than the severe pneumonia seen early in the pandemic.

Along with the intense sore throat, patients frequently report several other symptoms, including nasal congestion, runny nose, coughing, headache, fatigue and occasionally mild gastrointestinal upset. Fever may or may not be present.

Doctors emphasize that although the symptoms might seem milder in many people today, COVID-19 has not disappeared. Older adults, people with chronic illnesses and those with weakened immune systems can still develop serious complications from the infection.

Health experts say that the appearance of new symptoms should not be surprising. Viruses constantly change through mutation, and as the population develops immunity through vaccination and previous infections, the body’s response to the virus can also change.

As a result, the clinical picture of COVID-19 continues to evolve.

Physicians advise that anyone experiencing a sudden, severe sore throat, especially when accompanied by cold-like symptoms, should consider testing for COVID-19. Rapid home tests remain widely available and can help determine whether the virus is responsible.

Simple precautions still help reduce the spread of infection. Staying home when sick, covering coughs and sneezes, washing hands frequently, and testing when symptoms appear can all help prevent transmission to others.

While the world has learned to live with COVID-19, the virus continues to remind us that it is still changing and still capable of surprising doctors with new and unusual symptoms.

Michael Kossove is professor emeritus and an adjunct professor of microbiology at Touro University’s School of Health Sciences. He is a polio researcher, international polio lecturer and polio survivor. He can be reached at Professormike2@aol.com.