The ZOE Health Study last week released an updated list of the five most common Covid-19 symptoms reported by study participants—which differed depending on vaccination status.

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The 5 most common Covid-19 symptoms

On Thursday, the ZOE Health Study—a collaboration between researchers at Massachusetts General Hospital, the Harvard T.H. Chan School of Public Health, King's College London, Stanford University School of Medicine, and the ZOE health app—released a list of the five most common Covid-19 symptoms currently being reported by study participants.

To create the list, researchers analyzed data from the ZOE Covid Study app. The list is based solely on study participants' reports and does not factor in demographic information or which variant caused the infection. 

The updated list highlights the most common symptoms currently being reported by study participants, which differ depending on vaccination status.

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Study participants reported similar symptoms whether they were unvaccinated, partially vaccinated, or fully vaccinated. Four of the five most reported symptoms were found across all three groups, with sore throat, runny nose, persistent cough, and headache ranking in the top five—though the ranked order of those symptoms varied by vaccination status

Notably, vaccinated participants reported fewer symptoms over a shorter period, which suggests that they were less ill and recovered more quickly.

Among fully vaccinated study participants, the top five symptoms—ranked from most reported to least reported—are:

1. Sore throat

2. Runny nose

3. Blocked nose

4. Persistent cough

5. Headache

For individuals who have only had one dose of the vaccine, the top five symptoms—ranked from most reported to least reported—are:

1. Headache

2. Runny nose

3. Sore throat

4. Sneezing

5. Persistent cough

Among unvaccinated individuals, the top five symptoms—ranked from most reported to least reported—are:

1. Headache

2. Sore throat

3. Runny nose

4. Fever

5. Persistent cough

How the most prevalent symptoms have changed over time

While CDC still lists symptoms like fatigue, muscle or body aches, nausea or vomiting, and diarrhea as potential Covid-19 symptoms, many have been cited less frequently in the ZOE Health study over time. 

For instance, the "traditional" symptoms outlined by CDC since 2020, including loss of smell, fever, and shortness of breath fell to the sixth, eighth, and 29th ranks, respectively. Persistent cough, which was previously the most reported symptom among fully vaccinated individuals, now ranks fifth.

Notably, individuals infected with the omicron variant more commonly report sore throat than those with earlier variants. Most vaccinated individuals also experience a faster recovery with omicron than with delta.

According to Sergio Segarra, CMO at Baptist Hospital in Miami, when the BA.5 omicron subvariant became dominant in the United States in early 2022, younger patients experienced extreme fatigue.

Currently, CDC data shows that BA.5 is still the dominant strain in the United States, followed by BA.4.6, BQ.1.1, and BQ.1. The delta variant and earlier omicron variants like BA.1.1 and BA.2 are no longer being detected.

As the top Covid-19 symptoms continue to evolve, some medical experts have expressed concern that the symptoms, which closely resemble cold and flu-like symptoms, may be mistaken for other viruses as winter approaches. llan Shapiro, Chief Medical Affairs Officer for AltaMed, stressed the importance of testing since treatments vary for each virus. (Bink, The Hill/Nexstar, 10/23; ZOE Health Study release, 10/20)