How Do You Create a Vaccine for a Non-Existing Virus?

Is it possible to make a vaccination for a virus that has never been isolated and identified? Don't they need a sample of the virus or bacteria to create a vaccine for it? I mean, I am no Doctah Fauci, but it seems kind of obvious to me. The scary part is that they keep pushing these vaccines with no regard to safety and efficacy questions that continue to arise. As the most vaccinated countries on the planet - those vaccinated against a virus that hasn't been shown to exist - see the most prolific outbreaks of COVID, irresponsible authorities around the planet continue to push and push the vaccine. But what if the vaccine is causing more deadly mutations and variants!