In a recent study posted on medRxiv* Preprint server, Israeli researchers compared the short-term effects of the first and second boosters of the messenger ribonucleic acid (mRNA-based) coronavirus disease 2019 (COVID-19) vaccine BNT162b2.
Study: Safety of the 4th COVID-19 BNT162b2 mRNA (2nd booster) vaccine. Image Credit: Chikena / Shutterstock
Background
Studies show that wearable sensors such as smartwatches objectively and efficiently detect post-vaccination physiological changes. In addition, they are more sensitive and even individuals who do not report such a response can be continuously monitored for their response to vaccination. For example, smartwatches can accurately determine the heart rate of a vaccinated person. This correlates with the severity of the vaccine response. In addition, you can indicate when your heart rate will return to baseline levels.
Severe Acute Respiratory Syndrome The emergence of a new substance of concern (VOC) for coronavirus 2 (SARS-CoV-2) has weakened the immune defenses provided by COVID-19 vaccines, including mRNA-based vaccines. Studies have shown that the efficacy of the BNT162b2 vaccine, which controls morbidity within 3 months of booster immunization, decreased from 67.2-73.9% to 45.7-64.4%.
In the future, after a rapid increase in Omicron-related hospitalizations, countries like Israel have launched a vaccination campaign to administer a second mRNA booster shot. These campaigns focused on high-risk populations such as the elderly and immunodeficiency. However, people were hesitant to receive a second booster shot, mainly because safety was not yet established.
About research
The researchers conducted this study as part of a PerMed observational prospective study, enrolling 2,019 participants who received one or two doses of BNT162b2 booster to compare the short-term effects of both doses. did.
The team had sufficient smartwatch data to compare objective short-term changes in the level of physiological indicators in 508 of the 615 participants. They analyzed this data from 7 days before the second booster, ie, the baseline period of 7 days after vaccination.
Self-reported and physiological response to a second booster dose compared to the first booster dose. ((((AB) Response to the second booster recorded by the smartwatch. These figures show the mean difference between baseline and post-vaccination periods in (A) heart rate (n = 507) and (B) heart rate variability-based stress (n = 505). Means are shown as solid lines and 90% confidence intervals are shown as shaded areas. ((((CD) Comparison of reactions recorded by the smartwatch between the first and second boosters. The figure shows the difference between the second and first boosters (C) heart rate (n = 301) and (D) daily mean changes in heart rate smartwatch indicators (each change between post-vaccination and baseline period). Shows a boxplot of variability-based stress (n = 297). Each green dot represents one participant. ((((E) Comparison of reactions reported by participants between the 1st and 2nd boosters (n = 316). The bar represents the percentage of participants who reported a particular response. Error bars represent 90% confidence intervals.
Researchers adhered to the Centers for Disease Control and Prevention (CDC) guidelines and classified participants’ self-reported responses into severe, mild, and none. Researchers follow the first booster from other variables, including age and time from the first booster to the second booster, followed by the usual logistic regression to individually observe and analyze the severity of the response. I adapted the model.
Similarly, they fit a multiple linear regression model with the first and second boosters to control the same variables as the severity of two physiological indicators, heart rate and heart rate variability (HRV) -based stress. I investigated the relationship. First, they calculated the daily mean changes between the post-vaccination and baseline periods separately for the first and second boosts, followed by the difference between these two means for each participant. ..
Survey results
The authors found a significant increase in heart rate and HRV-based stressors in the first 48 hours after the second booster dose compared to baseline levels. However, these changes disappeared after the first 72 hours and the measurements returned to baseline levels.
A total of 615 participants received a second booster shot, of which 65.5% of individuals did not report new symptoms. The most frequently reported reactions were fatigue, headache, myalgia, colds and sore throat. In particular, these reactions diminished in almost all participants within 3 days.
There was a significant association between the severity of the response after the first and second boosters, with a p-value of less than 0.001. Conversely, there was no association between heart rate and the magnitude of physiological indicators including HRV-based stress, with p-values of 0.109 and 0.358, respectively.
A pairwise comparative analysis of the first and second boosters found no significant difference in physiological measurements between the second and first boosters. In addition, the degree of systematic response reported after the second booster was similar to that observed after the first booster. Therefore, 67.7% of the 316 participants did not report new symptoms after the second booster, compared to 65.8% after the first booster. Also, the most frequently reported reactions, such as fatigue, headache, myalgia, fever, and cold, remained the same after the first and second booster doses.
Conclusion
Study data showed that there was no significant difference between the two booster doses in terms of peak time, time to return to baseline levels of physiological indicators, and self-reported side effects. Therefore, this study highlighted the short-term safety of the second booster of the BNT162b2 vaccine. On the downside, most of the participants in the second booster immunoassay are over 50 years old, with a high proportion of underlying disease in line with current Israeli and CDC vaccination guidelines. Therefore, it was not possible to generalize the findings.
*Important Notices
medRxiv Publish preliminary scientific reports that should not be considered definitive as they have not been peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.
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