Long before the covid-19 pandemic, Americans were growing increasingly distrustful of vaccines and the experts who claim they are all equally effective and important. In early 2020, as many as one-third of American parents were intentionally delaying or skipping vaccines for their children. Although easy to dismiss, such views are instructive for those who want to convince the public that a vaccine against the coronavirus is important and worth using.

It is tempting to blame conspiracy theories for a growing distrust of vaccines, because refusing a lifesaving technology, particularly during a pandemic that is poised to kill over 400,000 Americans within a year, seems irrational. Yet dismissing those who are hesitant as ignorant or anti-science ignores the complex ways in which individuals and families are weighing information and trying to make decisions that feel safe and relevant to them.

We no longer live in an era when people follow expert advice without question. Rather, the democratization of information and cultural norms that demand individuals take personal responsibility for their health, including what products they consume, have created a landscape on which each of us must decide what feels safe, ethical and scientifically sound.

In my research on why parents reject some or all vaccines for their children, parents often told me that, despite public-health claims to the contrary, they don’t see all vaccines as equally important or beneficial for all people. Smallpox, they insisted, was different from chickenpox.

Others questioned claims of efficacy by pointing out how certain vaccines, like the one against pertussis (whooping cough), don’t provide lifetime immunity. Parents with whom I spoke saw vaccines as consumer products that they could choose cafeteria-style, consenting to one should it seem useful or important, while rejecting others. These parents are notably not “anti-vaxxers.” They simply trust their own judgment about what they and their children need more than they trust expert advice that offers what they typically called “a one-size-fits-all” approach to vaccines that did not feel relevant to their family.

Public-health experts are aware of the growing vaccine hesitancy. In fact, the World Health Organization identified it as one of the top threats to public health in 2019. It blamed lack of trust underscored by misinformation, inconvenience or complacency about the seriousness of infectious diseases. Most parents today have never seen the damage caused by vaccine-preventable diseases. Vaccines, they argue, are “victims of their own success.”

My research points to something different. What I find is that decades of public-health messaging that has asked individuals to take personal responsibility for their health, read labels, examine ingredients and be diligent consumers have been successful — and vaccine hesitancy is the result.

If familiarity with the seriousness of infections was the main driver of vaccine demand, we would not being seeing almost 40 percent of Americans express uncertainty about receiving a vaccine against SARS-CoV-2, the virus that causes covid-19. As coronavirus vaccines become more widely available in the coming months, public-health experts and researchers have a long-overdue opportunity to communicate more clearly about the goals of vaccines, which vary depending on the disease and vaccine itself.

Rather than continuing to promote a narrative that all vaccines are equally effective or essential, and thus the same, it is time to offer consumers clear information about each vaccine so they can make what feels like an informed choice. Doing so should make it easy to assure the public that the coronavirus vaccines are safe, effective and necessary, even though there is much that we do not yet know.

That we have two highly effective vaccines within a year of learning of the existence of the SARS-CoV-2 virus is incredible and offers evidence that with public investment in science and the ability to leverage collaborations, great things are possible. Clinical trial data makes clear that the two mRNA vaccines, which have received emergency use authorization, are highly effective at preventing serious illness and death from covid.

Yet other information about the vaccines is imperfect, and these uncertainties have left many who are interested in getting a vaccine hesitant to be among the first to receive it. Like many of the parents I spoke to in my research, they are not anti-vaccine but say they prefer to wait and see, which feels to them to be the safer path. They are also not ignorant or victims of misinformation, with as many as one-third of health-care providers expressing hesitance.

Unfortunately, many public officials, in an effort to increase vaccine acceptance, are promising that the vaccine will help us all “get back to normal” and are failing to explain how the vaccine will facilitate this. For example, Colorado Gov. Jared Polis (D), after the first discovery of the United Kingdom variant of the coronavirus in his state, pleaded with people to continue to exercise caution. He promised that once vaccines have been given out, “in a month or two,” people can expect to return to “finally going out again, going to malls … poker nights.”

This is the wrong approach, most of all because it probably over-promises what vaccination is likely to achieve in the short term, which could ultimately increase public skepticism. Despite their enthusiasm for the vaccines, leaders must make clear what a vaccine is likely to actually accomplish. They should explain that those who receive the coronavirus vaccine will need to remain vigilant against the possibility that they could still become infected, probably without symptoms, and unwittingly spread the disease; in short, those vaccinated will still need to wear masks, and they will not see an immediate return to “normal.”

This hardly makes the vaccine unimportant; those inoculated will be protected against serious illness, hospitalization and death. Despite insisting that we are “rounding third base” or “are on the two-yard line” of the pandemic, Polis and other officials risk further diminishing public trust and allowing the public to possibly feel betrayed when they learn the vaccine is not yet a “get-out-of-home-free” card.

How long immunity lasts is also unknown, although most expect that this vaccine will probably require boosters. While this seems like a weakness, it is true for a range of other vaccines that nonetheless save lives and for which the need for boosters was discovered over time.

For example, outbreaks of measles in 1989-1991, particularly among immunized preschool children and college students, revealed the need for a booster, which became the standard of care. Federal agencies and researchers monitor the effectiveness of vaccines and revisit recommendations, sometimes adding new vaccines and sometimes revoking recommendations for a vaccine that proves ineffective, as was the case with a nasal spray flu vaccine in 2016.

Parents in my research often pointed to these shifts to explain why they don’t fully trust claims of vaccine necessity or efficacy, too often presented with certainty. These changes should actually be reassuring, but most people, including many of the health-care providers with whom I spoke, are unfamiliar with these post-licensing monitoring systems. Those promoting coronavirus vaccines should acknowledge what is known and unknown and make clear that inevitable changes in recommendations are a strength that demonstrates ongoing evaluation of safety and efficacy.

Further, even without long-term immunity, vaccines that lower the rates of infection, illness and death in a community are important. Even if it is time-limited, protection against covid-19 matters to individuals and possibly others. Making this clear could increase usage.

One of the greatest risks to the long-term success of the vaccines against the coronavirus may come from overpromising benefits and understating uncertainty. Doing so risks further undermining trust in vaccines and the experts who promote them. Those who recommend vaccines — against covid and other vaccine-preventable diseases — must offer clear information about the differences among vaccines, including their varied strengths and limitations. Doing so could be an important step in empowering consumers and reducing hesitancy. Our lives might literally depend on it.