Side effects from COVID-19 vaccines short-lived, vary according to age, sex

Vaccines against the coronavirus disease 2019 (COVID-19) often cause temporary disturbances in cardiovascular, respiratory, and sleep physiology, according to a new study. Moreover, such perturbations can be detected by wearable devices.

“We find that vaccines temporarily impact measures of cardiovascular, respiratory, and sleep physiology, and that the degree of change in physiology is influenced by the manufacturer and dose of the vaccine and the gender and age of the vaccine recipient,” the researchers said.

A total of 69,619 individuals participated in the present retrospective analysis, all of whom were users of a wrist-worn biometric device and had received the AstraZeneca, Janssen/Johnson & Johnson, Moderna, or Pfizer/BioNTech COVID-19 vaccine. The wearable collected measurements of resting heart rate (RHR), respiratory rate (RR), and heart rate variability (HRV), and assessed sleep structure.

A voluntary vaccination survey earned nearly 100,000 responses regarding adverse events and showed significant differences in the likelihood of side effects depending on the vaccine manufacturer and dose, as well as patient age and sex. For example, the second doses of the AstraZeneca and Pfizer vaccines were significantly more likely to be asymptomatic than the corresponding Moderna jab. [J Appl Physiol 2021;doi:10.1152/japplphysiol.00420.2021]

Similarly, men were less likely to report side effects, as were those in the age groups of 30–39, 40–54, and ≥55 years as opposed to those 18–29- years of age.

In terms of device parameters, the researchers found that all vaccines induced elevations in RHR by the first night postjab, which quickly normalized by the second night. Analysis of variance (ANOVA) further showed that the vaccines’ effects on RHR differed according to the manufacturer (p<0.001) and dose (p<0.001), as well as according to patient age (p<0.001) and sex (p<0.001).

In particular, the first AstraZeneca dose and the second doses of Moderna and Pfizer vaccines induced significant increases in RHR. Women also tended to see larger spikes in RHR, as did younger vaccinees.

Vaccination had an opposite impact on HRV, which dropped after receiving the jab. Dose, manufacturer, age, and sex were all likewise important factors affecting the degree to which HRV was affected.

Aside from cardiovascular effects, all vaccines also induced perturbations on RR, which increased after receiving the shot. RR was elevated on the first and second nights after vaccination, only normalizing by the third and fourth nights. ANOVA revealed that the degree of impact on RR varied according to vaccine dose and manufacturer and participant age and sex (p<0.001 for all).

The same was true for sleep duration, which increased on the first and second night after the shot and returned to baseline levels by the third night. Vaccine manufacturer and dose, as well as participant age, but not sex, modified the effect of vaccination on sleep duration.

“These results are practically applicable to individuals anticipating receipt of a COVID-19 vaccine as they organize their postvaccine commitments as well as by policymakers and employers considering offering time off for vaccination,” the researchers said.