How do we conquer vaccine skeptics? We listen.

ASK on the street in Hong Kong if passersby will get the COVID-19 vaccine, and you may hear what I did: “Sometime.” “Maybe.” “No.”

Combating this hesitancy here and elsewhere will take more than opprobrium and exhortation. It requires tuning in.

A combination of deep-seated distrust in government, ignorance and lack of urgency — in a territory that has kept coronavirus cases low — means Hong Kong is now struggling to get enough residents inoculated. This week, when appointments opened for people over 30, tens of thousands of us rushed to book, picking between Chinese-made Sinovac Biotech Ltd. and the Pfizer-BioNTech vaccine. Many more, out of 5.5 million eligible in a population of 7.5 million, did not.

Hong Kong is a perfect storm of problematic factors, from political tumult to reports of seven deaths among more than 160,000 people given the Sinovac shot that have caused unease, though the incidents haven’t been linked to the vaccine. Even before the shots were made widely available, many indicated they would delay. But the city is hardly alone. Skepticism and anxiety are as old as vaccines themselves, haunting even inoculation pioneer Edward Jenner, and run from the backstreets of Lahore to high-end Paris neighborhoods.

It’s not a problem that can be brushed off. There’s little hope of life returning to normal, much less of conquering a virus that has killed 2.7 million and paralyzed economies, until enough people step up to achieve herd immunity — probably upwards of 70%. Even a small shortfall could be enough to cost lives and livelihoods.

The good news is that experience has taught us plenty about campaigns and resistance. Plus, while COVID-19 has been a catastrophe, it’s also an unprecedented opportunity, given the visible public health ravages, to change minds and prove the value of vaccines.

The less positive news is that the causes of skepticism are manifold and complex. Misinformation is one problem: We know that from episodes like the Nigeria polio vaccine boycott in 2003-04, or the scare around the diphtheria, pertussis and tetanus vaccination in the 1970s and 1980s. Today, social media means even very modest numbers of militant anti-vaxxers move fast through online chatrooms to conquer the hesitant, sometimes just by sowing doubt. A Facebook study showed a small subset of users was responsible for most of the skeptical content posted. But there are plenty more sources, from lack of trust in authorities to healthcare barriers to simple racism. Episodes like the 40-year Tuskegee syphilis study that denied Black men in the US state of Alabama diagnosis and treatment cast a long shadow.

It’s a far lengthier list for COVID-19, where disinformation was present from the start, fed by geopolitical tensions and polarized domestic agendas as in the US, where President Donald Trump minimized the threat and fed conspiracy theories. There was outright denial in places like Turkmenistan, reporting no confirmed cases, and Tanzania, which stopped publishing data last April.

The swift appearance of vaccines unsettled even more people, unclear where time was saved or how risks balance against rewards. Europe’s suspension of AstraZeneca’s COVID-19 vaccine over reports of blood clotting may be understandable as a show of caution, but real-world evidence suggests the shots are safe. Once sown, doubts are very hard to clear.

In a way, it’s odd that vaccines spark so much debate. Far fewer people feel so strongly about allergy medication or cough syrup. Heidi Larson, who runs the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine and studies rumors, connects it to the involvement of government and big business — institutions in which distrust runs high. In a recent address, she said it’s less an information problem than a relationship one. Low faith in authorities, as in Hong Kong or Lebanon, another skeptical hotspot, means few will take risks. It’s no accident that vaccine skepticism so often overlaps with poor governance and populist politics.

It’s clearly necessary to block anti-vaccine disinformation on social media platforms, but it’s not a solution on its own, any more than mandating the injection — a move that would further antagonize and polarize, damaging future efforts. Simply shutting down skeptics is a poor tactic when exclusion is half the problem.

For a long time, distrust in lifesaving shots seemed to me a fringe position stemming from ignorance. Then I had a child on the autism spectrum, and found myself interrogated far too frequently and too publicly on his vaccine schedule: Had he had the shot against measles, mumps and rubella, the MMR? It’s a reference to a long-discredited study that links autism and the inoculation that has done untold harm, turbo-charging the anti-vaccine movement. These were not uneducated people or conspiracy theorists, but they had questions.

That’s where we need to start.

Pictures of vaccinated celebrities, simple booking mechanisms, and basic access to injections are all important. But it’s vital to listen to the doubters and understand where the problems are coming from. The Philippines, for example, is still feeling the impact of a dengue vaccine that could worsen symptoms in people not previously infected. Some Hong Kongers will need to be reassured on the provenance and safety of vaccines. Elsewhere, it may be a question of explaining why it is a priority, when other health threats loom large, too. Tailoring the response matters, as does providing it from a locally respected source — whether doctors, priests or elders.

One option is what one US public health specialist described to me: Focus groups that connect peers and seek to answer questions and educate without preaching. His experience among Hispanic and other communities suggests naysayers are brought around after evidence from a friend or relative, or when an acquaintance has been vaccinated without adverse consequences. Behavioral science in areas like climate change shows similar results: We’re happier to change our views if someone we can relate to does the convincing.

Such efforts are possible almost everywhere. Community discussions won’t fix deep-seated distrust in government and may not reconcile everyone with science. It’s late — the push should have started months ago. But we can still reach enough people to make a difference.

BLOOMBERG OPINION