The difference I see with abortion is that the SCOTUS held in Roe v Wade that women have an affirmative right to an abortion under substantive due process of the 14th amendment. If the government coerced healthcare providers to stop providing abortions, this would be a direct infringement on a right protected by the constitution. Conversely, there is no constitutional right to /not/ get a vaccine. Of course, the demographics of the court has changed, so it's very possible the SC will rule that not getting vaccinated is also a constitutional right conferred by substantive due process.