COVID-19 mRNA-1273 Vaccine Shows Lower Risk of Adverse Events in Elderly: Study
A recent study published in JAMA Network Open has compared the risks of adverse events following COVID-19 mRNA vaccination in the elderly. The study focused on the Pfizer-BioNTech (BNT162b2) and Moderna (mRNA-1273) mRNA vaccines, which are currently the most commonly administered COVID-19 vaccines worldwide.
Previous research on adverse event risks associated with these mRNA vaccines has been limited, with few studies including the elderly or individuals with specific medical conditions. Additionally, vaccine efficacy and its impact on adverse event frequency have not been adequately explored.
To address this gap in knowledge, researchers conducted a retrospective cohort study between December 2020 and July 2021. They compared the risks of adverse events among individuals aged 65 and older who received either the BNT162b2 or mRNA-1273 vaccine as their initial SARS-CoV-2 vaccine.
The study utilized an innovative linked database that included information from Medicare claims and community pharmacies, covering over 50% of the Medicare population in the US. The researchers identified over 28 million individuals who received either vaccine and stratified them into three categories based on frailty status: pre-frail, non-frail, and frail.
The study analyzed twelve serious adverse events potentially related to COVID-19 mRNA vaccination, such as facial nerve palsy, myocarditis, myocardial infarction, thrombocytopenia purpura, pulmonary embolism, and deep vein thrombosis. The researchers monitored participants from the day they received their first vaccine dose until death, occurrence of adverse events, or the end of the 28-day follow-up period.
The findings of the study revealed that both the BNT162b2 and mRNA-1273 vaccines had low risks of adverse events in the elderly population. The most common events were pulmonary embolism and deep vein thrombosis, affecting a small percentage of participants.
Interestingly, the mRNA-1273 vaccine showed a reduced risk of adverse events compared to the BNT162b2 vaccine. It was associated with an 11% lower risk of thrombocytopenia purpura in non-frail individuals and a 6% lower risk of pulmonary embolism in non-frail subjects. The Moderna vaccine also appeared to offer better protection against subsequent COVID-19 diagnosis.
Although both vaccines were found to be safe for frail individuals, differences in adverse event risks were more significant among non-frail individuals. The mRNA-1273 vaccine demonstrated a 14% reduced risk of facial nerve palsy and an 11% reduced risk of thrombocytopenia purpura in non-frail participants.
Notably, individuals who received the mRNA-1273 vaccine without a history of deep vein thrombosis had a lower incident risk of developing the condition compared to BNT162b2 recipients.
In conclusion, this study suggests that the mRNA-1273 vaccine may be associated with lower rates of adverse events in the elderly population compared to the BNT162b2 vaccine. It highlights the importance of evaluating COVID-19 vaccine safety in different patient populations, including the elderly and those at higher risk of adverse events. Further research is needed to fully understand the variations in vaccine efficacy and safety and to consider factors such as frailty when evaluating vaccine performance.
