Israeli study confirms safety of COVID vaccines
In a first-of-its-kind study, researchers at Tel Aviv University equipped a group of Israelis with smartwatches and monitored their physiological parameters, such as heart and pulse rates and sleep patterns, to evaluate the safety of COVID vaccines.
Pfizer’s COVID-19 vaccine on the production line. Credit: Mike Mareen/Shutterstock
Of the 4,698 Israelis monitored, 2,038 received the booster dose of the coronavirus vaccine, allowing the researchers to compare measures before objectively and after the participants took the vaccine. Participants also filled out daily questionnaires about their health in a customised app developed for the researchers.
Researchers were also given permission to analyse the medical files of 250,000 members of Maccabi Health Services — anonymously, without any identifying details. Maccabi is one of Israel’s four primary health maintenance organisations.
From the analysis of all the data, researchers were able to evaluate the safety of the vaccines from the perspectives of what the patients reported, what the smartwatches objectively detected, and from the clinical diagnoses of the doctors.
The research was carried out by PhD student Matan Yechezkel under the supervision of Prof. Dan Yamin, Head of the Laboratory for Epidemic Research and led in collaboration with Prof. Erez Shmueli, Head of the Big Data Laboratory, all from TAU’s Fleischman Faculty of Engineering. The results have recently been published in The Lancet, a peer-reviewed medical journal based in Britain.
Medical files contained the date the booster vaccine was administered, allowing researchers to compare the condition of the vaccinated patient with his/her baseline condition from 42 days before receiving the vaccine to the condition 42 days after receiving the vaccine.
“We saw clear and significant changes after administration of the vaccine, such as an increase in heart rate compared to the pulse rate measured before vaccination,” said Prof. Yamin, “and then we saw a return to the participant’s baseline, i.e., the pulse levels after vaccination returned to their previous levels after six days. Hence, our study confirms the safety of the vaccine.”
The researchers also noted that “the most surprising finding was that the watches were more sensitive than the people they were monitoring. Many participants reported fatigue, headache, etc. after receiving the vaccine, and after two or three days reported that they felt normal and well.”
“In contrast, from examining their watches, we saw distinct changes in heart rate that continued for several more days. There were also vaccinated participants who did not report any side effects at all and yet definitely experienced physiological changes based on data from their smartwatches. In other words, we learned that the smartwatches were more sensitive to changes in general feeling than the participants themselves.”
The researchers paid special attention for 25 unusual side effects attributed to COVID vaccines. After checking the frequency of side effects among the Maccabi members, they found no serious incidents associated with the vaccination.
“We found the vaccine to be safe to use,” Prof. Yamin said. “The smartwatch sensors ‘felt’ that the vaccine was safe, the vaccinee himself reported that the vaccine was safe, and finally, the doctors determined that the vaccine was safe. The results of the study have far-reaching implications regarding objective testing of vaccine safety in the future.”
