Both vaccines consist of two main doses and have shown good safety in clinical trials, with mild side effects such as:
For all vaccines in the United States, anyone can report adverse events using the Vaccine Adverse Event Reporting System (VAERS), a long-standing reporting system. established by the US Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration (FDA).
With VAERS, U.S. residents and their healthcare providers or vaccine manufacturers can submit any events that occur after the vaccine is received. These reports are classified as non-serious, severe or deceased.
The v-safe system, administered by the CDC, was developed specifically for the COVID-19 vaccination program and includes smartphone-based surveys sent daily for the first week after vaccination ( and longer intervals in subsequent months) to monitor for adverse reactions.
Study author Dr Hannah Rosenblum, of the US Centers for Disease Control and Prevention (CDC), said: “Vaccines are the most effective tool for preventing severe and beneficial COVID-19 disease outcomes. benefits of vaccination in preventing serious illness and death. .
This study reviewed available VAERS data and safety self-report data from December 2020 to June 2021 following either Pfizer-BioNTech or Moderna mRNA vaccine doses.
During the study period, more than 298 million doses of the mRNA vaccine were administered (132 million Moderna and 167 million Pfizer). Of the 340,522 adverse events reported to VAERS during the study period, approximately 4500 (1.3%) were fatal, with more than 80% of these deaths occurring in persons 60 years of age or older. .
Because the COVID-19 vaccine has been authorized for emergency use, healthcare providers are required to report all deaths following vaccination, regardless of direct association. potential next. The study authors noted that no abnormal patterns were detected in the cause of death reports.
Of the nearly 8 million v-safe participants, more than half reported local and systemic reactions following vaccination, occurring more frequently after dose two than with dose one..
More v-safe reports of inability to work, perform normal activities or seek medical attention have been reported after dose two, than after dose one. Less than 1% of participants said they sought medical attention after either dose of the vaccine.
VAERS and v-safe are important tools that CDC can use when assessing vaccine safety and to help identify any unexpected or unusual events.
These data ensure that reactions to both mRNA vaccines are usually mild and subside after a day or two—Confirmation reports from clinical trials and post-authorization follow-up.
The authors acknowledge some limitations with this study. First, the VAERS system is based on spontaneous reporting and is not representative of the entire population. In addition, the need for smartphone access to participate in v-safe does not cover populations that do not have access to these devices.
Finally, although trends in adverse reactions were observed between Pfizer-BioNTech and Moderna mRNA vaccines, neither VAERS nor v-safe could definitively measure safety differences. between the two vaccines.