Just over half of all frontline health workers in a new poll said they have received at least their first dose of a coronavirus vaccine, a figure that highlights challenges ahead as the nation drastically scales up its vaccination effort.

Health workers were the first groups of people to be prioritized for getting vaccines when the first doses began being administered. But three months in, just 52 percent of frontline health workers said they received a shot, according to the Washington Post/Kaiser Family Foundation Poll.

A large majority of unvaccinated health care workers who either have not decided if they will get vaccinated, or say they do not plan to get vaccinated, expressed worries about potential side effects as well as the newness of the vaccine.

According to the survey, two-thirds of respondents expressed a distrust in the government to ensure the safety and effectiveness of the vaccines. 

While the top concerns are consistent across key demographic groups, three-fourths of Black health care workers who have not received a COVID-19 vaccine cited distrust of the government as a major factor in their decision.

Education and partisanship also played a role in vaccine acceptance. Large shares of adults without a college degree, as well as Republican and Republican-leaning adults said they are not confident the COVID-19 vaccines have been properly tested for safety and effectiveness. 

The survey was conducted from Feb. 11 to March 7. At the start of the survey, vaccines from Pfizer-BioNTech and Moderna had been authorized. The Johnson & Johnson single dose vaccine was authorized Feb. 27.

The poll includes interviews with a nationally representative sample of 1,327 frontline health care workers representing hospitals, doctors offices, outpatient clinics, nursing homes and assisted care facilities, and those working in home health care. 

The margin of sampling error for the total frontline health care worker sample is plus or minus 3 percentage points. 

The same disparities shown among health workers mirror the national population. According to the survey, only 39 percent of Black health workers, and 44 percent of  Hispanic frontline health workers reported personally receiving a COVID-19 vaccine, compared to nearly 60 percent of white health care workers.

Part of the reason for such a relatively low vaccination rate could also be a lack of access. Only 34 percent of home health workers were offered a COVID-19 vaccine from their employer, compared to eight in ten of those working in hospitals, and majorities working in nursing homes or assisted care facilities, outpatient clinics, and doctors offices.

Across the country, vaccine supply has been the biggest obstacle to getting shots in arms, but health officials have said that will change in a matter of weeks. Already, more than 75 million people have been vaccinated and the number is growing by about 2.5 million every day.

The Biden administration is working on national education campaigns to try to counter the concerns of the vaccine-hesitant. Experts and federal health officials have acknowledged the hard work ahead to ensure enough of the country gets vaccinated in order to bring the pandemic under control.