What You Should Know: Breakthrough Infections
Apoorva MandavilliCoronavirus reporting
Breakthrough infections can occur more frequently with the highly contagious Delta variant than with other versions of the virus. But the dates are still unclear.
There is some evidence that people infected with the variant are walking around 1,000 times more viruses in your body than those infected with previous variants and can remain contagious longer.
If that applies even to people who have been vaccinated, some of them may be able to pass the virus on to others.