Each fall and winter, a triple threat of viruses – influenza (the flu), respiratory syncytial virus (RSV), and COVID-19 – puts people at risk. A new analysis from the Evernorth Research Institute has found that since COVID emerged early in 2020, it has continued to exert a significant burden on health systems and state and local governments throughout the United States.
“All three viruses remain active across the United States,” said Urvashi Patel, Ph.D., vice president of the Evernorth Research Institute. “Overall, we’re not seeing any indication that rates of COVID, the flu, and RSV are falling, which is reflected in hospitalizations and emergency department visits.”
New vaccines and strategies can go unused
The prevention, diagnosis, and treatment of these three viruses has evolved greatly over the last few years with the introduction of new vaccines, rapid diagnostics, antiviral medications that can be taken at home, and the personalization of strategies such as mask wearing and when to miss work or school.
For example, RSV vaccines were approved in 2023 for older adults and younger children, yet large numbers of people did not receive a vaccine due to payment and supply issues or personal preference. In all, about 14% of adults 60 or older were vaccinated against RSV by the end of 2023, compared with 33% who received a COVID vaccine and 62% who received a flu shot.
A deep dive into disease prevalence, trends, and demographics
To prepare its analysis, the Evernorth Research Institute used de-identified member data from January 2021 through June 2023. The population in the analysis included 33.5 million commercially insured people of all ages.
- The highest prevalence rate of COVID (474 cases per 10,000 people) was seen in January 2022.
- The highest prevalence rates of RSV (11 per 10,000) and the flu (60 per 10,000) were seen in November 2022.
- The prevalence rate of COVID declined toward the end of 2022.
- Meanwhile, the prevalence rates of the flu and RSV were higher during the winter months (November through February) of 2022-2023 than in those months a year earlier.
Prevalence rate (per 10,000) of COVID, flu, and RSV by month: 2021
Prevalence rate (per 10,000) of COVID, flu, and RSV by month: 2022
Prevalence rate (per 10,000) of COVID, flu, and RSV by month: 2023
- Among adults, women were diagnosed more frequently with COVID or the flu, while men were diagnosed more frequently with RSV.
- Flu was most prevalent among people in the 6-17 age group, averaging 85 per 10,000.
- COVID was most prevalent among people 35-59, averaging 2,407 per 10,000.
- RSV had the highest impact among children 5 or younger, with an average prevalence of 62 per 10,000.
Average prevalence rate per 10,000 by year and gender: 2021-2023
- In 2021, the highest average prevalence of COVID was in the Northeast, while the South had the highest average prevalence of flu and RSV.
Average prevalence rate per 10,000 by year and region: 2021
- In 2022 and during the first six months of 2023, the South had the highest prevalence of all three viruses.
Average prevalence rate per 10,000 by year and region: 2022-2023
Midwest (MW), Northeast (NE), South (S), West (W)
- In 2022, the states with the highest average prevalence rates for COVID were New Mexico, Connecticut, Mississippi, New Jersey, and Illinois.
- The highest average prevalence rates of the flu in 2022 were recorded in Mississippi, Louisiana, Kentucky, Oklahoma, and Texas.
- The states with the highest average prevalence rates of RSV in 2022 were Louisiana, Texas, South Dakota, Iowa, and Illinois.
- The prevalence of emergency department utilization, office visits, and inpatient visits for COVID and the flu increased from 2021 to 2022.
- The prevalence of visits to urgent care for COVID declined from 2021 to 2022.
Where do we go from here?
Experts are concerned that high levels of the flu, RSV, and COVID may converge over the next few months, which could be overwhelming for our health care system. Employers and health plans play an important role in encouraging vaccination through strategies such as targeted educational materials, incentives that encourage vaccination, and workplace vaccine clinics for members and their families.
“The increases in cases associated with ‘waves’ of viruses are substantial and put considerable strain on local health care systems,” said Shannon Custer, chief operating officer and vice president, Evernorth Workplace Care. “The variabilities in disease prevalence and utilization identified in this analysis can be useful for facilitating effective interventions and resource allocation while anticipating and planning for surges in upcoming months.”
