The last 14 months have given the world a series of public health challenges that it has never had to grapple with before.

Will people willingly disrupt their lives in order to contain the spread of a potentially lethal virus? Can drug manufacturers develop and test a vaccine in a very short period of time that is effective against COVID-19? Will those same pharmaceutical companies be able to ramp up manufacturing capabilities quickly enough to satisfy the demand for those vaccines?

In terms of vaccine creation and distribution, there’s no doubt that it’s been an unqualified success. Every estimate indicates that the United States will be awash in vaccines by May. However, the question that is looming on the very near horizon is the most important and difficult to answer: will the United States be able to vaccinate enough of the population to get to a state of herd immunity and finally put an end to this year long nightmare?

It’s not the hard sciences that are under the microscope, it’s the social sciences. To reach herd immunity, most experts believe that a country needs to get at least 75% of the population fully vaccinated as a minimum threshold. Will that even be possible? Are societal factors like religion actually making the goal of herd immunity even more difficult?

The organization Data for Progress has been putting a poll into the field since the very beginning of the pandemic in March of 2020 as a way to get a sense of what percentage of the public is engaging in risky behaviors and how they feel the government is handling the crisis. Since January they have begun to ask respondents questions about their receptiveness to the vaccine. What these results indicate is that there are some reasons for hope, but there is also ample evidence that getting shots into arms may prove to be a lot more difficult in the very near future.

The survey asked respondents if they had received at least one dose of the COVID-19 vaccine. As can be quickly inferred, those shots were in short supply in January. Just about 6% of the entire sample indicated that they had gotten the vaccine at that point. However, things improved rapidly from there and the share of Americans who had been inoculated essentially doubled every month from January through early April, when 44% of the population had gotten a dose of the vaccine.

However, when the sample is broken down into the three of the largest religious groups: White evangelicals, White Catholics and the religiously unaffiliated, some disparities begin to emerge.