Most Common COVID-19 Symptoms by Immunization Status: Graph

• Symptoms of COVID-19 are a little different for people who have been vaccinated and those who have not been vaccinated, according to a study.
• Unvaccinated people are more likely to report a fever and a persistent cough.
• They are also more likely to get seriously ill and have reported more symptoms overall.

The Delta variant defies vaccines more than any other strain of coronavirus: it appears to make it easier for vaccinated people to spread the virus and become infected on their own, according to data from the Centers for Disease Control and Prevention.

Vaccines always protect against serious illness – a leaked CDC presentation showed vaccines reduced the risk of hospitalization or death from Delta 25 times. But a small minority of vaccinated people can develop a “breakthrough case” of COVID-19.

The CDC records about 35,000 breakthrough cases per week among 162 million vaccinated Americans, a rate of 0.02%. These data may be limited, as the CDC in May stopped tracking asymptomatic, mild and moderate breakthrough cases nationally.

So far, groundbreaking cases are more likely to look like a cold than our original picture of COVID-19, which focused on symptoms like fever, dry cough, and shortness of breath.

The following table shows the five most common COVID-19 symptoms based on your immunization status. The data comes from the COVID Symptom Study, a project that tracks self-reported COVID-19 symptoms in more than one million people in the UK.

Vaccinated people have milder illnesses and faster recoveries

Studies in England and Scotland indicate that Pfizer’s vaccine reduces the risk of symptomatic Delta infection by 88%, compared to 95% for the original strain. The vaccine also reduces the risk of any type of Delta infection by 79% and Delta hospitalization by 96%, according to the studies.

It’s no surprise, then, that the biggest difference between infections among vaccinated and unvaccinated in the COVID symptom study was the severity and duration of their illnesses. People who were vaccinated reported fewer symptoms, which were more fleeting, than those who were not vaccinated.

Delta appears to cause more severe disease than the other variants, making vaccines all the more necessary to protect against hospitalization and death. The CDC recently estimated that unvaccinated people accounted for about 97% of COVID-19 hospitalizations in the United States.

“Whether you have been vaccinated or not, it determines how sick you might become,” Dr Barney Graham, deputy director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases, said in a discussion last month. “But what determines the likelihood of you getting infected is the amount of infection around you in the community.”

He added that “you are more likely to get infected if you are partially immune, or you are more likely to be seriously ill if you are not at all immune.”

Differences in symptoms

Headaches, runny nose, and sore throat were commonly reported in the COVID Symptom Study, regardless of a person’s immunization status. But fully vaccinated people were more likely to report loss of smell, and unvaccinated people were more likely to report fevers. A persistent cough was also more common in unvaccinated people and those who had only received a single dose of the vaccine than in fully vaccinated people.

Shortness of breath was relatively rare overall, even in unvaccinated people. Part of the reason could be that young people – who are less likely to develop severe symptoms – account for a larger share of COVID-19 cases now than they were at the start of the pandemic. (An Imperial College London study that was not peer reviewed found that coronavirus cases in the UK were 2.5 times more common in those under 50 than in those 50 and more in June.)

That said, the symptoms of COVID-19 can still run the gamut. A recent CDC analysis of an outbreak in Barnstable County, Massachusetts found that a cough, headache, sore throat, muscle aches, and fever were common symptoms in people. presenting cases of breakthrough. Almost 80% of breakthrough cases in this community were symptomatic.