Behavior Remains the Barrier to Defeating COVID-19

 

This week, the White House announced that the United States will not meet the target of vaccinating 70% of American adults by July 4th. Back in April, many people here in Denver were driving a hundred miles to get their vaccine doses in rural areas the minute they became available. What gives? As usual, human behavior rather than medical expertise is the limiting factor in addressing health challenges.

A recent national survey identified four main reasons that people weren't yet vaccinated. Together they add up to around 35% of adults, or about the number who haven't yet gotten a COVID-19 vaccine.

1. Watchful Waiting (about 8%) - these people aren't yet convinced that the vaccines are efficacious or safe. An often-cited argument that might tell you someone is in this group is the fact that the vaccine hasn't yet been FDA-approved, but is still in an "emergency authorization" phase. That's of course true. Normally, the FDA approval process involves multiple phases of scientific study and takes years. Even then, sometimes a drug has unexpected side effects or contributes to unanticipated long-term health problems. The FDA process is designed to reduce those chances as much as humanly possible, but the only real way to know the risks is to release the drug to everyone and monitor what happens. Because COVID-19 was such an immediate and serious threat, the agency used an "emergency authorization" method where the regular steps were still followed (Phase 1, 2, and 3 clinical trials, with thousands of people receiving vaccines in placebo-controlled studies), but where there is more attention to benefit and speed rather than making sure every possible safety question was answered. In short, the Watchful-Waiting group is not wrong that the COVID-19 vaccine is a little riskier than ordinary vaccines or drugs, or at least it was back in January. With hundreds of millions of people now vaccinated, we know a great deal more than we did 6 months ago about the vaccines' safety and efficacy. Despite a few well-publicized risks such as rare blood clots in younger women with the J&J one-dose vaccine, all of the vaccines have proven to be quite safe and highly efficacious, providing robust resistance to different strains of the coronavirus and under different conditions of exposure. Some commentators have said that the vaccines actually work much better than we have any right to expect, given the accelerated timeframe for development and the virulence of the SARS-CoV-2 virus. Still, it's a well-documented fact that people have different levels of risk tolerance under conditions of uncertainty, and the long-term effects of the COVID-19 vaccine may remain unknown for years. (Most of us just evaluate that risk in relation to the long-term effects of COVID-19 itself, which are known and quite disturbing). One might expect that the Watchful-Waiting group will gradually become more accepting of COVID-19 vaccines as more people around them get the vaccine without being harmed. Eventual full FDA authorization of vaccines might also help to persuade this group to get vaccinated.

2. Cost-Anxious (9%) - these people may not be aware that COVID-19 vaccines are free, or more likely can't afford the "cost" in terms of time away from work, childcare, or other responsibilities. Young adults have been the group least likely to get COVID-19 vaccines so far, and for them the "cost" may be inconvenience, or else a fear of vaccine symptoms that is disproportional to their fear of the disease itself. They may (erroneously) believe themselves not to be vulnerable to COVID-19 because it's true that most deaths have been in older adults, but of course some deaths have been in young people and the debilitating symptoms associated with "long COVID syndrome" appear to be distributed relatively equally across age groups. Access to health care was a barrier early on when vaccines were available in limited doses, competition for vaccine appointments was fierce, and people had to go to large-scale vaccination sites to get their first and second dose. The addition of many retail pharmacies to the list of COVID-19 vaccine distribution sites increased convenience this spring, and vaccine appointments are now much easier to get, so the barriers to receiving a vaccine have decreased. This group may further benefit from on-site COVID-19 vaccine distribution at schools, workplaces, or primary care physicians' offices as we move toward fall and more normal work/life patterns resume. Financial incentives to get vaccinated might also change the cost-benefit calculation for this group. One additional "cost" for young adults in particular may be the psychological challenge of feeling vulnerable to a disease; people sometimes insulate themselves from this cost by not thinking about potential health risks. The early limitation of COVID-19 vaccines to older and sicker people might have fueled this association in people's minds. The antidote is to make vaccination normal and expected, and workplace or school policies that require vaccination are also likely to help in this regard.

3. System Distrusters (4%) - these people are who we often mean when we talk about "vaccine hesitancy"; they have a basic lack of trust in the health care system, often because of legitimate grievances about how they have been treated in the past. People in minority groups and in economically or socially vulnerable areas are unfortunately less likely to have received a COVID-19 vaccine, either because of access problems as in group #2, or because they don't believe the health care system has their interests at heart. The healthcare system overall needs to do a better job of providing culturally competent care; COVID-19 is just one example of lingering health disparities that affect people in almost every type of medical condition. The System-Distruster group unfortunately is a symptom of a long-term problem, and addressing their needs won't be easy. Some current efforts involve outreach by community members, such as engaging Native American elders to increase vaccine acceptance in members of their tribes. Culturally tailored public health messages are another strategy that CDC and others are pursuing to increase vaccine acceptance among groups that traditionally have less trust for medical science. COVID-19 is also a striking example of health disparities, with minority and disadvantaged people being more likely to contract the virus, as well as more likely to experience severe health problems or die; reminding people of these risks, and framing vaccination efforts as a form of advocacy to protect them, may also help to increase vaccine acceptance. Making progress with System Distrusters will certainly take extra time and effort, but as a beneficial side effect it may lead to progress in addressing inequalities that our health care system has struggled with for decades.

4. COVID Skeptics (14%) - this group is the largest, and unfortunately also the most difficult to reach. For them, COVID-19 has become a matter of politics or identity, and they are likely to refuse vaccination in the name of "freedom" or because of various conspiracy theories. Younger and less educated people are more vulnerable to believing in conspiracies, as are people with symptoms of depression. Ideally one could correct the false beliefs involved in people's COVID-19 skepticism, but in practice this is much harder than just providing information. Strategies like motivational interviewing are most likely to have an effect, listening to people's concerns or beliefs and repeatedly emphasizing that it's their own choice whether or not to be vaccinated. This is true even in the face of employer or school mandates -- people are free to make a cost-benefit decision about whether to comply or whether to face the consequences of noncompliance. It's important to remind people in this group that they may not like the choice, but that it is still theirs to make. And for policy-makers, it's also important to hold the line on vaccination mandates in the face of almost certain (and vehement) opposition. Ultimately some of the people in this group are likely to grudgingly accept vaccination, although others never will.

All of this of course applies only to adults. So far the vaccination rates for adolescents 12-17 have been encouraging, although there are some regional differences. When thinking about vaccinations overall, parents tend to over-weight the risks of vaccine side effects and to under-weight the risks of the diseases the vaccines are designed to protect against. This may be because the anticipated regret of "doing something" that turns out to harm a child feels very risky, while the consequences of "doing nothing" can be viewed as chance or fate rather than being the parent's fault. Additionally, many groups have presented the notion that "COVID is not harmful to children," often at a level that is out of alignment with the actual evidence. Presenting realistic information about children's COVID-19 risk may be important to encourage parents to vaccinate, especially when vaccine availability is (hopefully) extended to children under 12 later this year. In general, parents' perception of disease risk is the strongest predictor of whether they accept vaccinations for their children. Additionally, schools could certainly mandate COVID-19 vaccination just as they mandate other vaccines; some parents will opt out, although public health data suggest that the vast majority will comply with the requirement. 

With about two-thirds of the U.S. adult population now vaccinated, we seem to have hit a ceiling. Making further progress will require a detailed understanding of who is not yet vaccinated, and the use of different messaging strategies that are tailored to the needs of different groups. People always behave the way they do for some reason (all behavior is "functional," in other words). To move forward we need to address the underlying concerns or problems that have made people reluctant to accept vaccines even in the face of those vaccines' remarkable success at COVID-19 prevention.