Significantly more people who are vaccinated against COVID-19 ended up in the hospital with the virus in September than in previous months, according to the Pennsylvania Department of Health.
These so-called “breakthrough” hospitalizations are caused by a number of factors, including the decrease in antibodies from vaccination over time and an increase in the percentage of vaccinated people, the health department said.
“Vaccines are not 100%. So there always will be some people who will get an infection after being vaccinated. And if 100% of people [in the state] are vaccinated, we're still going to have some cases, and then those cases will be 100% of the vaccinated,” said Pennsylvania Department of Health Acting Physician General Dr. Denise Johnson.
In September, 26% of the nearly 5,000 people hospitalized with COVID-19 were vaccinated, the department said.
That’s up from prior estimates from health systems, which stated about 10% of people hospitalized with COVID-19 had gotten the vaccine.
State data show that since January, about 7% of COVID-19 patients hospitalized were fully vaccinated; however, a very small percentage of Pennsylvanians were fully vaccinated at the beginning of the year. Combining recent data with that from the winter and spring makes it appear that the vaccine is more effective than it is.
Additionally, the more infectious Delta variant was not detected in the U.S. until March of this year. Johnson said that it now comprises “probably 99%” of current cases.
Average daily COVID-19 cases are up 37% since early September, according to an analysis of state data. Over the past week, an average of 4,862 people have tested positive for the virus each day.
Data from the Centers for Disease Control and Prevention show that 59% of all Pennsylvanians, including kids, are fully vaccinated. Children under 12 are not eligible for the vaccine.
Researchers estimate that COVID-19 vaccines lose some of their effectiveness after about five months — a window of time that has passed for Pennsylvanians who were inoculated early this year. Some higher-risk people are eligible for booster shots.
“The great news is the vaccines are still working and working very well in preventing severe illness and hospitalization,” said Johnson. “That's what we expected to see.”
