Are COVID Symptoms Different in Vaccinated People?

People who are vaccinated but still get COVID are less likely to develop severe symptoms, experts have said, but not necessarily different symptoms to those of unvaccinated people.

The fact that COVID vaccines help reduce severe illness and hospitalizations has been well documented in several real-world reports.

A November study authored by dozens of scientists aimed at evaluating the association between COVID vaccination with the Moderna and Pfizer vaccines and hospitalization with COVID. It looked at 1,983 COVID patients between March 11 and August 15, 2021.

The study found that unvaccinated patients accounted for 84.2 percent of COVID hospitalizations and also found that patients whose disease progressed to death or mechanical ventilation were significantly less likely to have been vaccinated.

The U.S. Centers for Disease Control and Prevention (CDC) has stated there is a growing body of evidence that confirms vaccines reduce the risk of severe illness by 90 percent or more in fully vaccinated people.

But the Omicron variant in particular has shown that it is still possible for patients to get infected with COVID despite being fully vaccinated. In cases like these, known as breakthrough infections, do patients notice different symptoms to unvaccinated people?

"I haven't seen reports of different symptoms occurring in breakthrough infections compared to unvaccinated COVID-19 cases, but those who experience a breakthrough infection are more likely to have asymptomatic or mild disease," said Eric Freundt, associate professor of biology at the University of Tampa.

Matthew Frieman, associate professor of microbiology and immunology at the University of Maryland School of Medicine, echoed the point.

"I have not seen any data suggesting specifically different sets of symptoms between vaccinated and unvaccinated other than just overall severity of disease," he told Newsweek.

And according to Johns Hopkins Medicine, symptoms of breakthrough COVID are "similar" to those in unvaccinated people "but are generally milder." Some people with breakthrough COVID may not notice any symptoms at all.

That being said, Tim Spector, professor of genetic epidemiology at King's College London and co-founder of the ZOE COVID symptoms study in the U.K., told Newsweek that in his experience vaccinated people appear to show less symptoms like fever, breathing problems, muscle ache, and possibly rash.

In any case, even if a person is vaccinated, it could be a good idea for them to go and get a COVID test if they develop COVID symptoms or "any symptom that is not typical for you," Johns Hopkins Medicine adds.

COVID vaccine
A COVID vaccine being given to a medical worker in Santiago, Chile, on December 24, 2020. Data shows that COVID vaccines significantly reduce risk of severe disease. Marcelo Hernandez/Getty