This requirement applies both in cases of adjustment of status (for those already within the US) and for applicants applying at US embassies and consulates. As far as the Indian diaspora is concerned, majority of the green card applications relate to adjustment of status. Applications are filed by those already within the country, say on H-1B extensions.
Proof of full Covid-19 vaccination with a vaccine authorised for use in the US or listed for emergency use by the World Health Organization is required to be submitted when attending the medical examination. Applicants must receive the vaccine regardless of evidence of immunity or prior Covid-19 infection.
This vaccination requirement does not cover those applicants who are not eligible owing to the age-limit for vaccines in their jurisdiction or those who can document a medical contraindication. If an applicant objects to the vaccine on religious or moral grounds, a waiver request has to be made to the US Citizenship and Immigration Services (USCIS).