PENNSYLVANIA — The proportion of COVID-19 infections and hospitalizations among vaccinated Pennsylvania residents rose sharply last month, though the shot remained broadly protective, according to new statewide health data released Friday. The latest Department of Health data on so-called “breakthrough” infections shows that between Sept. 5 and Oct. 4, vaccinated people represented just over a quarter — 26% — of more than 135,000 new infections and nearly 5,000 hospital admissions across the state. Death statistics for the last 30 days were not available because of lags in reporting and verification. When the Health Department released its initial set of data on breakthrough cases Sept. 14, just 6% of cases and 5% of hospitalizations since January were among vaccinated residents. State health officials attributed COVID-19’s increased impact on vaccinated people to the rise of the highly transmissible delta variant of the coronavirus, along with waning immunity among some populations that have received the vaccine, among other factors.