Fully vaccinated people continue to be well protected against severe disease and death, even with Delta, but so-called breakthrough cases, where a person gets infected despite being fully vaccinated, are on the rise. Because of that, many experts continue to advise caution, even if fully vaccinated.
Keep your mask on in public and otherwise act as if you're unvaccinated. This is especially true if you're removed from the population mean in age, health, comorbidities by a standard deviation or two or three.
The unvaccinated typhoid Mary's are spreading hugely infectious doses of the Delta variant through the air.