AUSTIN (Nexstar) — Texas is among several states suing the Biden administration over COVID-19 vaccination rules taking center stage in the U.S. Supreme Court in a special session Friday. 

In a special session, the high court will hear arguments about the White House’s vaccine-or-test rule for large employers and a separate vaccine mandate for some healthcare workers — both matters that Texas has sued the federal government over. 

Attorney General Ken Paxton has filed at least five lawsuits against the Biden administration and federal government over its vaccination mandates. Here’s a timeline from the five lawsuits and where those stand:

Oct. 29, 2021Paxton sued the Biden administration over requirements for federal contractors to be vaccinated against COVID-19. A federal judge blocked this rule from being enforced on Dec. 7 in a lawsuit brought by other states.

Nov. 5, 2021 — Paxton joined several other states in a lawsuit against the Biden administration over its vaccine-or-test policy for private companies with more than 100 employees. This OSHA rule covers nearly 84 million workers. After being temporarily blocked, the 6th Circuit Court of Appeals reinstated the rule. That could change depending on how the U.S. Supreme Court rules; it will hear this case on Friday.

Nov. 15, 2021 — Paxton sued the Biden administration for COVID-19 vaccination requirements of healthcare workers at facilities receiving Medicare or Medicaid funding. This policy from the Centers for Medicare and Medicaid Services covers more than 17 million health-care workers at 76,000 facilities. A federal court in Texas granted a preliminary injunction on Dec. 26, blocking its enforcement. This case is also up before the U.S. Supreme Court on Friday.

Dec. 10, 2021 — Paxton sued the Biden administration for its vaccine requirements for all staff and volunteers of the Head Start school readiness program and mask mandate for children attending it. On Tuesday, a federal district court grants a preliminary injunction blocking its enforcement in Texas.

Jan. 4, 2022 — Paxon and Gov. Greg Abbott sued the Biden administration for its vaccine mandate for members of the Texas National Guard.

The Republican AG has consistently said these challenges are to correct what he views as “unconstitutional” federal government overreach.

In a Dec. 22 statement, the White House vowed to defend its initiatives.

“Especially as the U.S. faces the highly transmissible Omicron variant, it is critical to protect workers with vaccination requirements and testing protocols that are urgently needed,” said Jen Psaki, the White House press secretary. “We are confident in the legal authority for both policies.”

Randy Erben, an adjunct professor of law at the University of Texas, said it’s difficult for those affected by this to know what to do while everything pends in the courts.

“The landscape is changing not only every week, but every day and sometimes hourly,” he said. “Until you get that final order out of that highest court, you’re never going to have any resolution.”