COVID Symptom Study app reveals most common vaccine side effects

pharmafile | April 28, 2021 | News story | Research and Development COVID-19, Vaccine, data 

An analysis of over 600,000 people’s vaccine reports has been published in The Lancet Infectious Diseases journal, in the largest real-life study of COVID-19 vaccine side-effects in the world.

Data was gathered through the ZOE COVID Study app, which was run in association with the National Institute for Health Research and King’s College London.

The ZOE study researchers looked at self-reported symptoms in 627,383 people using their app in the eight days after being vaccinated.

The study found that the most common side effects of the COVID-19 vaccines are pain or tenderness at the injection site. With roughly one in four people having wider effects like fever, headache, nausea and fatigue.

About 70% of people who had the Pfizer jab experienced some reaction around the injection site, including pain, tenderness, redness or swelling, compared with just under 60% for the AstraZeneca jab.

Most after effects peaked within24 hours of vaccination and usually lasted between one to two days.

The ZOE study actually found fewer side effects with both the Pfizer and AstraZeneca vaccines than have been reported in clinical trials.

Analysis from the app users also found that COVID vaccine after effects were more common among people under 55 years old and women especially.

ZOE contributors who had a confirmed case of prior COVID-19 were also three times more likely to have whole body effects after the first dose of the Pfizer vaccine and almost twice as likely after the AstraZeneca jab, than people who had never knowingly been infected.

People who previously had COVID-19 were also more likely to experience local effects in their arm after their jab.

Tim Spector OBE, lead scientist on the ZOE COVID Symptom Study app and Professor of Genetic Epidemiology at King’s College London, said: “Our findings should reassure people that after effects from COVID vaccines are usually mild and short-lived, especially in the over 50s who are also most at risk from COVID-19.

“This study also shows the value of collecting real-time large-scale information about symptoms and after effects through the ZOE COVID Symptom Study app.”

Kat Jenkins

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