President Joe Biden’s mass coronavirus vaccination effort has taken a blow after breakthrough infections were discovered at the White House and within House Speaker Nancy Pelosi’s office.

As the delta variant spreads nationwide, Biden is still short of administering at least one COVID-19 shot to 70% of adults, a July 4 target he set for himself in May. The more dangerous and contagious version of the virus is behind the spike in cases and caused a stock market dip.