OPINION: How can we get people to trust the AstraZeneca and other vaccines?

News Update: A U.S. trial found that AstraZeneca’s vaccine was 79 percent effective with no serious side effects, according to results released on Monday.

The European Medicines Agency, Europe’s top drug regulator, confirmed last Thursday that the Oxford-AstraZeneca Covid-19 vaccine is safe. In some ways, that shouldn’t be news: It had previously received approval by the E.M.A. and some 20 million people in Europe have already received doses, largely without issue. But earlier in the week, several European countries temporarily halted inoculations out of concern that it caused blood clots.

Now that regulators have reaffirmed the AstraZeneca vaccine’s safety, we need to address the next key challenge: confidence and trust in it. Although the vaccine has been given the official green light, the reported risks and the temporary suspensions have heightened anxieties and increased hesitancy.

Among the 20 million people who have received the AstraZeneca vaccine in Europe, 25 people developed blood clots following vaccination. The rate of blood clots that would normally occur among unvaccinated people is in fact much higher. But given the newness of the vaccine, every reported side effect is being carefully considered. This is a good thing. Instead of being scared, we should be reassured that the safety system is working.

That isn’t how last week’s developments were received, though.

When multiple European countries temporarily suspended distribution, it triggered anxieties around the world. ...

This month, the World Bank issued a report on countries’ Covid-19 vaccine readiness. The findings were concerning when it comes to the human side of vaccination: In the 128 countries reviewed, only 30 percent had plans to train the vaccinators needed to administer the new vaccines and only 27 percent had developed public engagement and social mobilization strategies to motivate people to get vaccinated.

This is a shocking finding, given how long we have known that these new vaccines were on the way. Planning for — and investment in — communication and engagement should have started the day governments began making advance purchases. ...