Inter-individual variation in objective measure of reactogenicity following COVID-19 vaccination via smartwatches and fitness bands

Abstract

The ability to identify who does or does not experience the intended immune response following vaccination could be of great value in not only managing the global trajectory of COVID-19 but also helping guide future vaccine development. Vaccine reactogenicity can potentially lead to detectable physiologic changes, thus we postulated that we could detect an individual’s initial physiologic response to a vaccine by tracking changes relative to their pre-vaccine baseline using consumer wearable devices. We explored this possibility using a smartphone app-based research platform that enabled volunteers (39,701 individuals) to share their smartwatch data, as well as self-report, when appropriate, any symptoms, COVID-19 test results, and vaccination information. Of 7728 individuals who reported at least one vaccination dose, 7298 received an mRNA vaccine, and 5674 provided adequate data from the peri-vaccine period for analysis. We found that in most individuals, resting heart rate (RHR) increased with respect to their individual baseline after vaccination, peaked on day 2, and returned to normal by day 6. This increase in RHR was greater than one standard deviation above individuals’ normal daily pattern in 47% of participants after their second vaccine dose. Consistent with other reports of subjective reactogenicity following vaccination, we measured a significantly stronger effect after the second dose relative to the first, except those who previously tested positive to COVID-19, and a more pronounced increase for individuals who received the Moderna vaccine. Females, after the first dose only, and those aged <40 years, also experienced a greater objective response after adjusting for possible confounding factors. These early findings show that it is possible to detect subtle, but important changes from an individual’s normal as objective evidence of reactogenicity, which, with further work, could prove useful as a surrogate for vaccine-induced immune response.

Safety of the fourth COVID-19 BNT162b2 mRNA (second booster) vaccine

“…While our cohort size is relatively reasonable compared to other studies using wearable devices, it has a rather large paired-wise sample 18,19,21 . In particular, most of the participants in our second booster analysis are over 50 years old, in line with current Israeli and CDC vaccine administration guidelines 22,23 .…”

“…Several recent studies have demonstrated the excellent performance of wearable sensors such as smartwatches in detecting physiological changes following vaccination, as they can continuously monitor reactions in an objective manner 18–21 . Impressively, they have been shown to be even more sensitive than humans in detecting vaccine reactions 18,19 , even in individuals who did not report any reactions following vaccination 18 .…”

“…Impressively, they have been shown to be even more sensitive than humans in detecting vaccine reactions 18,19 , even in individuals who did not report any reactions following vaccination 18 . It has been shown, for example, that changes in heart rate measures following vaccination correlate with the severity of vaccine reactions and could accurately determine when participants’ heart rates returned to baseline levels 21 .…”

Individual Factors Associated With COVID-19 Infection: A Machine Learning Study

“…Shabbir and collaborators (28) have implemented a strategy based on exploratory data analytics from diverse sources, coupled with telemonitoring and the use of internet of things (29)(30)(31) to detect COVID-19 severity in the context of smart hospitals (32)(33)(34). Also relevant is the use of concepts from computational social science (ambient intelligence, in particular) and again data from wearables (in this case, smartwatches) to develop early warning alerts (35)(36)(37). Several additional approaches to use machine learning to prevent or warn in advance for COVID-19 are discussed in the monographic review by Saeed et al (38).…”

The digital phenotype of vaccination

“…The level of deviation from normal was moderate. For example, a mean increase of only 1.5 beats per minute in resting heart rate, a decrease of 1,600 daily step count and an increase of 35 min of night sleep were observed after a second mRNA vaccine dose 7 . Yet these findings tracked well with established knowledge of subjective assessments of reactogenicity, such as significantly greater changes in those receiving the Moderna versus the Pfizer/BioNTech vaccine and in those receiving the first dose response in people with prior COVID-19 infection (Fig.…”