You will need a public interest group to (financially) back that play. The people who could afford to personally bankroll that case wouldn't be interested and aren't going to be vaccine-carded anywayHell, if the damn shot wanes after 6 months, you probably have longer lasting natural immunity anyway.
I think that people who have natural immunity from overcoming the disease, and they’re denied access to public accommodations because of vax status, they should sue the **** out of whoever denied them. They should sue the government for whatever rile they had in it. The day in court should force both sides to bring their best evidence to settle this issue. People who have overcome the disease don’t need the ***damn shot.