July 8 (Reuters) - A new analysis has shown that combining the influenza vaccine and the COVID-19 vaccine at the same time was not associated with a higher likelihood of side effects compared to receiving the seasonal flu vaccine alone.

Using data collected between 2022 and 2025 from the U.S. Department of Veterans Affairs' health care system, researchers assessed the incidence rates of 46 different side effects over 90 days in more than 700,000 people who received both vaccines, and about 1.8 million people who received only the flu vaccine.

The average age was close to 70 years.

Researchers in the Annals of Internal Medicine reported that taking two vaccines against the two viruses on the same day did not increase the likelihood of cardiovascular and thrombotic complications, neurological disorders, immune disorders, or any other serious or clinically significant adverse effects.

They noted that the result did not change depending on the type of COVID-19 vaccine used or the year it was received.

The researchers concluded that "the results support the safety of concurrent vaccination in the elderly in the short term, and may help to enrich ongoing discussions about vaccine policies and individual risk-benefit assessments."

The U.S. Centers for Disease Control and Prevention and several major medical organizations have previously stated that receiving both vaccines together is a convenient way to maintain protection without the need to schedule a second appointment.

During Robert F. Kennedy Jr.’s tenure as U.S. Secretary of Health and Human Services, the Food and Drug Administration said it “cannot confirm the safety and effectiveness of receiving both vaccines at the same time.”

In April, Moderna received approval from the European Commission for its combined influenza and COVID-19 vaccine for adults aged 50 and older. The vaccine is currently undergoing regulatory review in the United States.