Vaccinated people as the only survivors could still carry a sufficient reservoir to ensure the demise of anti-vaxers... maybe cut down the global human population by 60-70 percent* and give the environment/biosphere some time to heal.
As God intended !
* I know that some "vaccine resistors" will call that cold, harsh, inhumane etc, which is supremely ironic considering their "they were going to die anyway" attitude toward people with co-morbidities like asthma, diabetes, heart conditions, hangnails...
Those 4-5 billion people who would die under my optimized scenario "were going to die anyway".