Self-reported data from nearly 1 million Americans show an 8% to 11% higher rate of mostly mild systemic adverse events after simultaneous seasonal flu vaccine and mRNA COVID-19 booster (third) doses than with the COVID-19 booster alone.In the study, published today in JAMA Network Open, the Centers for Disease Control and Prevention (CDC) COVID-19 Response Team and Emory University analyzed rates of systemic adverse events among 981,099 Americans aged 12 years and older in the week after either simultaneous flu and COVID-19 booster doses or the booster alone from Sep 22, 2021, to May 1, 2022.
Volunteers responded to at least one health survey through the CDC's smartphone-based v-safe monitoring system during the study period.The authors noted that current clinical CDC guidance states that COVID-19 vaccines may be given without regard to timing of other vaccines, including during the same vaccination visit.
Authorization of COVID-19 vaccine boosters in the United States coincided with the recommended period for flu vaccination, increasing the odds of simultaneous receipt.Fatigue, headache, muscle aches most reportedOf the 981,099 volunteers, 92,023 (9.4%) reported having received simultaneous flu and COVID-19 booster vaccination.
Of these participants, 59.7% were female, 40.6% were aged 12 to 49 years, 25.8% were 50 to 64, 27.0% were 65 to 74, and 6.6% were 75 or older.A total of 58.9% of 61,390 participants who simultaneously received the flu vaccine and the Pfizer/BioNTech COVID-19 booster and 68.6% of 30,633 of those who simultaneously received the flu vaccine and the Moderna booster reported systemic adverse reactions.Participants who simultaneously received the flu and Pfizer vaccine (aOR, 1.08; 95% CI, 1.06 to