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I'm a Virus Expert and Here's a Sure Sign You've Had COVID

Watch these infection signs for the vaccinated and the unvaccinated.

By Dr. Amira Roess, as told to Matt Gillick

Getting vaccinated from coronavirus is now a race against the spread of the new Omicron variant—and the existing Delta variant. While many people continue to get vaccinated, millions are still hesitant or skeptical. According to medical experts, this is now primarily a pandemic of the unvaccinated. The vaccines, however, do not fully protect against COVID. Breakthrough cases are possible. The vaccines' protection against getting infected with the previous variant Delta ranges from 39 percent to 96 percent. Symptoms of breakthrough infections can be non-existent or, on rare occasions, severe. There are two camps of COVID patients, and depending on one's vaccination status, their experience with the virus differs. 

Dr. Amira Roess is an infectious disease expert and professor of Global Health and Epidemiology at George Mason University's College of Health and Services. She provided information about the likely indications someone has COVID for the vaccinated and the unvaccinated. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


Signs of Infection for the Vaccinated

Sick woman with flu at home

If you have been diagnosed with COVID-19 this year, it is likely you were infected with the Delta variant—or going forward, Omicron is possible. If you are experiencing symptoms and have been in close contact with someone infected, it is a good idea to get tested. Symptoms experienced by vaccinated individuals are generally milder than those experienced by unvaccinated people. Generally, symptoms are like a mild cold and can include cough, fever, headache, and loss of taste or smell. These less severe symptoms often do not lead to hospitalization. The majority of COVID hospitalizations are among unvaccinated individuals. When breakthrough infections happen, they tend to result in asymptomatic or mild symptoms. A small fraction of breakthrough cases end up in hospitalization, predominantly individuals with underlying health conditions and older folks.


Signs of Infection for the Unvaccinated 

woman covered by a blanket on the sofa with high fever and flu

95% of new cases come from the unvaccinated population. Unvaccinated individuals may experience cough, fever, chills, muscle aches, headaches, loss of taste or smell, and many other symptoms. They may endure these symptoms for much longer than those who are vaccinated, which could result in hospitalization. Preliminary data analysis suggests that among unvaccinated individuals, the Delta variant may cause more severe symptoms than the Alpha variant. We are waiting for much-needed data to help answer this question. We do know that the Delta variant infects more individuals. There is also compelling evidence of a longer duration of infectiousness among the unvaccinated compared to the first strain of COVID-19. Individuals infected with the Delta variant can infect about twice as many individuals as we had observed in people infected with the Alpha variant.

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Get Vaccinated

Woman with face mask getting vaccinated, coronavirus, covid-19 and vaccination concept.

These vaccines protect people from serious illness and hospitalization by up to 90%. To limit the spread, wear an N95 mask or facial covering. Social distancing while indoors and participating in group activities outside as much as possible is also crucial in stopping the proliferation of this highly contagious variant. 

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What to Do If You Think You're Infected

Doctor wearing protection mask against covid taking notes during consultation with patient in medical clinic

Says the CDC:

"COVID-19 affects different people in different ways. Infected people have had a wide range of symptoms reported – from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus. People with these symptoms may have COVID-19:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

Look for emergency warning signs for COVID-19. If someone is showing any of these signs, seek emergency medical care immediately:

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to wake or stay awake
  • Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

Call your medical provider for any other symptoms that are severe or concerning to you.

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How to Stay Safe Out There

Brunette woman wearing a KN95 FPP2 mask.

Follow the public health fundamentals and help end this pandemic, no matter where you live—get vaccinated ASAP; if you live in an area with low vaccination rates, wear an N95 face mask, don't travel, social distance, avoid large crowds, don't go indoors with people you're not sheltering with (especially in bars), practice good hand hygiene, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Matt Gillick
Matt Gillick has been writing about world news, culture, and sports since graduating from Providence College in 2015. He received his MFA from Emerson College in 2021. Read more about Matt