There are many requirements when immigrants seek to become lawful permanent residents of the United States. 
Taking a medical exam is one such requirement.
The purpose of the exam is to ensure public safety. 
On October 1, 2021, the COVID-19 vaccine was added to that list.
Objections to this action, as one might expect, quickly arose.
The vast majority assert it violates their religious freedom. 
Yet, when I question them to gauge their chances for success, the responses of most cast doubt about their sincerity.   
Recommended Links For More Information:
https://www.carlosbatara.com/give-more-than-ask-in-return/ (Immigrants Who Give More To Others Than They Ask For In Return)
https://www.bataraimmigrationlaw.com/covid-19-guidelines-immigration-interviews (COVID-19 Has Changed Immigration Interviews. What You Need To Know)