The BNT162b2 mRNA COVID-19 vaccine did not escalate the risk of most of the adverse events assessed, as per the findings of a study carried out by Noam Barda et al. Using data from the largest health care organization, the researchers assessed vaccine's safety with respect to a wide range of noxious events in a nationwide mass vaccination setting.

For each potential noxious event, in a population of people with no prior diagnosis of that event, the vaccinated people were individually matched to unvaccinated people as per the clinical and sociodemographic variables. Using the Kaplan-Meier estimator, the risk ratios and risk differences at forty-two days following vaccination were procured.

For placing these findings in context, a similar assessment was carried out involving coronavirus-infected people matched to uninfected people. Similar noxious events were investigated in the vaccination and coronavirus infection assessment. In the vaccination assessment, the control and vaccinated groups each incorporated a mean of 884,828 participants. Vaccination was significantly linked with a magnified risk of myocarditis, lymphadenopathy, appendicitis, and herpes zoster infection, as shown in Table 1:

COVID-19 was linked with a considerably increased risk of myocarditis (risk ratio 18.28; risk difference 11 events per 100,000 persons) and of additional severe noxious events, including thrombocytopenia, deep-vein thrombosis, pericarditis, myocardial infarction, arrhythmia, pulmonary embolism, and intracranial hemorrhage.

The  BNT162b2 was linked with a magnified risk of myocarditis (one to five events per 100,000 persons). The risk of myocarditis and numerous other severe noxious events considerably elevated following SARS-CoV-2 infection. Additional research is warranted for estimating the potential of long-term noxious events.