Well-Being Prevention & Cures

Flu and COVID-19 vaccine uptake remain low

Less than 13 percent of eligible people have gotten the bivalent coronavirus booster.
older adult getting a shot in the upper arm from a medical professional
iStock

Story at a glance


  • Flu is hitting heavy in many states.

  • Flu shot coverage among adults is as low as 19 percent in some states.

  • What people believe about their health and what information they have access to, officially or through their circles, affects decisions they make.

Although this year’s flu season started early and is tracking to be a difficult one, flu shot uptake is below what it was at the same time of year in previous seasons. And despite warnings of a possible winter coronavirus surge, uptake for the bivalent COVID-19 vaccine also remains low nearly three months after it became available in early September.

Flu shot uptake has been trailing rates from previous years since early October, according to data from the Centers for Disease Control and Prevention (CDC). 

According to data through mid-November, child flu vaccination rates are similar to last year’s at 40 percent, but some state coverage rates are lower than the 2020-2021 and 2019-2020 seasons. Adult coverage across all 50 states and Washington, D.C., ranges from 18.9 to 35.6 percent, according to the CDC — a decrease from recent years, when flu shot coverage has ranged from 45 to 50 percent in adults 18 and over.

In a typical year, at best around 50 percent of eligible people could be expected to get a flu shot over the course of the season. This is considered good preparation for any influenza season, since it may prevent enough people from getting severely sick and going to the hospital to lessen the burden on health systems and prevent deaths in vulnerable populations, as public health officials aim to do.

In regard to COVID-19, as of Nov. 15 a little over 39.7 million people in the U.S. had received the updated bivalent booster shot, according to the CDC. This represents about 12.7 percent of people eligible for the shot, which includes everyone aged 5 and older. 

The 65 and older population are getting the bivalent shot at a higher rate than other age groups, with 32.6 percent, about 17.8 million people, having done so. 

This is still falls short of the uptake seen in the original campaigns for coronavirus vaccination. In the U.S., about 80 percent of eligible people have received at least one dose, and just under 69 percent have completed the primary series (i.e. two doses of an mRNA vaccine). 

Why is uptake low?

These numbers may in part reflect how people are thinking about their health and the potential benefits of a flu shot or coronavirus booster, experts suggest.

In a study published in 2021 in Research in Social and Administrative Pharmacy, researchers found that people ages 18 to 49 showed more vaccine hesitancy, as well as people in lower income populations. They asked respondents questions like whether they believe the shots would help, whether they know how it works and if they think it’s important to protect others. Among people who responded that they would not get the flu shot, about 20 percent said they believed the shot gave them flu — though vaccination does not do that — and about 38 percent said that they do not believe it helps. 

The researchers wrote about how the Health Belief Model could affect flu and COVID-19 vaccine uptake. This model “proposes that the perception of a personal health behavior threat is influenced by at least three factors, general health values, which include interest and concern about health; specific health beliefs about vulnerability to a particular health threat; and beliefs about the consequences of the health problem,” according to a book from the Academic Press

There are a few ways that this thought process could influence choices. For example, each person could essentially be conducting a clinical trial with a sample size of one. They may consider their own past experiences on whether they normally get very sick from the flu and draw conclusions about how beneficial the shot could be to them personally. 

In this way, each person is acting like an individual investigator, gathering data points through their networks. This effect could be exacerbated when real world data is lagged or incomplete. 

Data on COVID-19 is also not as reliable or accessible as it used to be, and this can negatively affect risk calculations and perception of risk. The first part of risk assessment is assessing personal risk, and the second part is assessing risk to others around you. When data is fragmented or unreliable, that calculation becomes much more complicated because “your risk is a function of how well we understand the force of transmission and how much the virus is hanging around,” says epidemiologist Delivette Castor at Columbia University.  

Misinformation may influence how people think about the flu vaccines as well. “There’s a whole social structure to that in terms of access to information education,” says study author Anandi Law at Western University of Health Sciences. “And then there are cues to action, which is what kind of information are you getting from elsewhere. And that could be media, could be a friend, could be anywhere.” 

There may also be cognitive biases at play. A person might only remember cases that confirm their belief on whether the flu shot is helpful or not. Or they may believe they always get sick after getting the shot, and that may lead them to think that the shot isn’t working or made them get the flu.

The flu shot does not make recipients sick, although a person’s immune system may become active in response. 

Another possible reason that the initial COVID-19 vaccination campaigns were more successful than the current push for the bivalent booster is that there was still urgency in fighting the pandemic when the first shots were rolled out.

“No matter where you were, as you saw people around you suffering, getting in the hospital, dying from it,” says Law. “Eventually, self-preservation, wanting to live, overpowers any other kind of conviction, whether it’s political, whether it’s faith.” 

Now however, the general feeling of urgency has faded for many people which may be why vaccine uptake is low. After nearly three years of living in a pandemic, there is a lot of fatigue around COVID-19 communications and vaccinations. Even the tens of thousands of new cases and hospitalizations and hundreds of new deaths each day may not be triggering the same reactions as earlier in the pandemic. 

There’s a lot more work to be done to understand how people process information, how long a kind of information remains sticky with people and then how public health officials can evolve their communication so that it remains factual and ethical for people who are making judgements based on that information, says Castor. 

There are many reasons and pieces of information that someone might consider in deciding whether to get a vaccine. “We’ve learned a really key lesson in COVID which is that everyone doesn’t make decisions the same way,” Castor continues. “The work that we have to do is to actually understand what those constellation of factors are at any point in time, in order to address them.” They also may not be static and may change for any one person or population over time. 

It’s still unknown what could be the optimal goal for coronavirus booster coverage. For influenza, even with annual campaign efforts, the country still sees an average of up to 60,000 deaths each year. “There is still some hesitancy, and I don’t think we’ll ever be at zero hesitancy,” says Law.