Studies: More US adults roll up sleeves for flu than COVID, RSV vaccines

Band-Aid after vaccination

CDC / Lauren Bishop

A trio of new studies provide a snapshot of US adult vaccine uptake and views, with two showing the highest coverage for flu, followed by COVID-19 and respiratory syncytial virus (RSV), and one confirming greater willingness to get a flu shot than a COVID-19 shot.

RSV vaccine uptake low in nursing home residents

Late last week in Morbidity and Mortality Weekly Report (MMWR), researchers from the Centers for Disease Control and Prevention (CDC) probed national uptake of the three vaccines among residents of nursing homes that reported data to the National Healthcare Safety Network in fall 2023.

"Nursing home residents are at risk for becoming infected with and experiencing severe complications from respiratory viruses, including SARS-CoV-2, influenza, and respiratory syncytial virus (RSV)," the investigators wrote.

"In 2023, the Food and Drug Administration approved the first two RSV vaccines for adults aged ≥60 years, making the 2023–2024 respiratory virus season the first in which vaccines against SARS-CoV-2, influenza, and RSV are simultaneously available in the United States," they added.

As of December 10, 33.1% of nursing home residents had received the updated COVID-19 vaccine, and 72.0% and 9.8% living at facilities that report flu and RSV uptake, respectively, had received those vaccines.

COVID-19 vaccine coverage ranged from 22.5% in Arkansas, Louisiana, New Mexico, Oklahoma, and Texas to 42.9% in Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming. Rates were highest (38.5%) in the least socially vulnerable counties and lowest (29.1%) in the most vulnerable. They were also higher in small nursing homes (37.3%) than in medium (32.3%) and large homes (32.2%).

Flu vaccine uptake ranged from 64.3% in Alaska, Idaho, Oregon, and Washington to 79.9% in Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming. Flu vaccine coverage was greatest in the least socially vulnerable counties (73.7%) and lowest in the most socially vulnerable (70.9%). Rates were also higher in small nursing homes (77.4%) than in medium (72.2%) and large facilities (69.8%).

RSV vaccination rates ranged from 5.9% in Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee to 24.8% in Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming. Uptake was highest in the least socially vulnerable counties (10.7%) and lowest in the most socially vulnerable counties (8.7%). Coverage was highest in small nursing homes (15.3%) and lowest in large homes (8.0%).

Possible reasons for low vaccine demand include "vaccine fatigue," inaccurate health information, and vaccine hesitancy, especially in socially vulnerable areas, the authors said. "Lower coverage in areas with higher social vulnerability might be related to challenges to vaccine access and cost and payment barriers associated with COVID-19 vaccine commercialization," they wrote.

Ongoing surveillance of vaccination coverage among nursing home residents remains essential to help guide timely efforts to increase vaccination in this population at high risk and address inequities.

The low RSV vaccine uptake could be a result of its relative newness, implementation challenges, limited time to train providers and develop protocols, and less staff familiarity with the risk of outbreaks and severe disease.

"Because vaccination coverage varied by vaccine type, region, SVI [Social Vulnerability Index], and facility size, ongoing surveillance of vaccination coverage among nursing home residents remains essential to help guide timely efforts to increase vaccination in this population at high risk and address inequities," the researchers concluded.

Variations by race, region

For a second study in MMWR, CDC researchers parsed fall 2023 data from the National Immunization Survey-Adult COVID Module, a random phone survey of US adults used to track COVID-19, flu, and RSV coverage.

By December 9, about 42.2% and 18.3% of adults reporting receiving a flu and COVID-19 shot, respectively, while 17.0% of older adults and 21.4% of those with chronic conditions said they were vaccinated against RSV. About 27% and 41% of adults and 53% of older adults said they would definitely, probably, or were unsure whether they would receive the three vaccines.

The proportion of unvaccinated adults who said they definitely would get vaccinated fell as uptake rose, from 33.2% to 9.4% for flu, and 28.2% to 14.1% for COVID-19. The decline was less for RSV vaccine, from 20.9% to 14.1%.

The percentage of unvaccinated adults who reported they probably or definitely wouldn't get vaccinated was lowest for RSV, while the proportion of those who were unvaccinated and said they probably would get vaccinated or were unsure was highest for RSV.

"Immunization programs and vaccination partners are encouraged to use these data to understand vaccination patterns and attitudes toward vaccination in their jurisdictions to guide planning, implementation, strengthening, and evaluation of vaccination activities," the researchers wrote.

Immunization rates for all vaccines was lowest among uninsured respondents, while uptake and intent to be vaccinated climbed with age and were higher among those living in urban and suburban areas than in rural areas.

Flu vaccine uptake was higher among White and Asian adults than among most other racial groups, but the proportion reporting that they probably or definitely wouldn't get vaccinated against flu was comparable among White and Black adults (both 32.2%) and lower among Hispanic respondents (24.0%).

Updated COVID-19 and RSV vaccine uptake was higher among White people than among most other racial groups, but a higher proportion of White adults said they probably or definitely wouldn't receive a COVID-19 vaccine (43.2%) than Black (31.3%) and Hispanic (34.7%) adults.

Immunization programs and vaccination partners are encouraged to use these data to understand vaccination patterns and attitudes toward vaccination in their jurisdictions to guide planning, implementation, strengthening, and evaluation of vaccination activities.

Likewise, a higher percentage of White respondents reported that they probably or definitely wouldn't get vaccinated against RSV (32.5%) than Black (15.3%) and Hispanic (19.3%) adults. Uptake of all vaccines varied by region, from 15.6% to 54.8% for flu, 2.4% to 35.6% for COVID-19, and 1.9% to 32.4% for RSV.

"Immunization programs and vaccination partners are encouraged to use CDC developed dashboards and tools, as well as other data sources available to them, such as immunization information systems, to identify undervaccinated populations and better understand vaccination patterns, attitudes and behaviors, and systemic barriers to vaccination in their jurisdiction to help tailor vaccination activities to improve coverage and health equity," the investigators wrote.

More respondents say flu vaccine safer

Last week in JAMA Network Open, a team led by Harvard researchers described the results of a probability-based survey of US adults conducted from July 7 to 16, 2023. The survey asked about perceptions of COVID-19 and flu vaccine effectiveness and safety, vaccination intentions, and reasons for hesitancy.

"As the viral landscape shifts, there is new urgency to understand US adults’ views on relevant vaccines, including whether they perceive annual vaccines similarly, or whether there are differences that may impact coadministration and communications," they wrote.

In total, 42% and 40% of adults said that COVID-19 and flu vaccines, respectively, are very effective at preventing severe illness and hospitalization. A higher proportion indicated that flu vaccines are very safe (55%), compared with 41% for COVID-19 vaccines. Nearly half (49%) said they were very likely to get vaccinated against flu, compared with 36% who said they would receive a COVID-19 shot. Findings were similar among adults aged 50 and older.

Where coadministration [of both vaccines] is offered, communications should lead with the more popular influenza vaccine, provide consistent messaging on safety and effectiveness of both vaccines, and address vaccine-specific beliefs, such as the limits of protection from prior COVID-19 infection.

Relative to flu vaccine-hesitant adults, a larger share of COVID-19 vaccine–hesitant adults cited insufficient research, concerns about vaccine safety and effectiveness, the belief they were already protected through previous vaccination or infection, and distrust of government agencies and drug companies. Findings were similar among older adults.

"Where coadministration [of both vaccines] is offered, communications should lead with the more popular influenza vaccine, provide consistent messaging on safety and effectiveness of both vaccines, and address vaccine-specific beliefs, such as the limits of protection from prior COVID-19 infection," the authors wrote. "Public health agencies should also work with trusted messengers to build trust."

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