Fauci said, "When you look at the level of virus in the nasopharynx of a vaccinated person who gets a breakthrough infection with Delta, it is exactly the same as the level of virus in an unvaccinated person who's infected,' Fauci said."
So a vaccinated person who gets covid is going to spread covid "Exactly the same" as a non-vaccinated person with covid.
And, unfortunately, data from Israel is showing that, "Pfizer and BioNTech’s Covid-19 vaccine is just 39% effective in Israel where the delta variant is the dominant strain, according to a new report from the country’s Health Ministry."
The same CNBC article also says,
"The two-dose vaccine still works very well in preventing people from getting seriously sick, demonstrating 88% effectiveness against hospitalization and 91% effectiveness against severe illness, according to the Israeli data."
So the vaccine isn't preventing the spread of covid, it's just lessening the symptoms:
The stated goal of the covid vaccine from the beginning was to lessen the symptoms, not to prevent infection, and therefore you getting the vaccine can only provide protection for yourself by, hopefully, reducing your symptoms.