St. Louis County health officials say less than 1% of those who have received the COVID-19 vaccine have contracted the coronavirus.
The St. Louis County Department of Public Health has recorded 212 coronavirus cases among the more than 350,000 county residents who have received the vaccine, according to a recent advisory.
Public health experts say the small number shows the vaccine is significantly effective at preventing people from getting sick and dying.
“We want the community to be aware that the vaccine is terrifically effective when you look at the small number of people who have these breakthrough infections,” said Dr. Jim Hinrichs, the department’s infectious disease adviser.
Put in other terms, if the Fox Theatre in St. Louis' Grand Center neighborhood had all of its 4,500 seats filled with vaccinated patrons, just two or three of them would test positive for the virus.
Most of the 212 vaccinated people who contracted the virus had minor symptoms or no symptoms at all. Thirteen were hospitalized, and one person died.
“Even if you do get an infection with COVID, you’re probably going to get a cold or a bad cold,” said Dr. Michael Kinch, Washington University vice chancellor.
So-called “breakthrough cases” are inevitable with any vaccine, he said.
“That’s a natural consequence of the fact that no vaccine has been 100% protective unfortunately, so it’s normal,” said Kinch, who studies drug development. “There are going to be rare occasions where someone can still be infectious even if you get vaccinated, and that’s why everyone needs to get vaccinated.”
Tracking cases in vaccinated people can give clues to how effective the vaccine works over time — particularly against newly emerging variants, county health officials say.
“Those are some questions that are still unanswered as to how effective the vaccine will continue to be,” Hinrichs said.
“We interview those people, try to come up with some common denominators that could help us educate the community that it is important to still be aware,” he said.
For example, one-third of vaccinated St. Louis County residents who tested positive for the virus are health care workers who were among the first people to receive the vaccine in Missouri.
That could indicate that prolonged contact with sick people could increase the risk of reinfection. It could also mean that the vaccine could lose some effectiveness over time, Hinrichs said.
Many people in that group contracted the virus from family members at home who had not been vaccinated, he said.
Hinrich said vaccinated people should continue to be cautious, especially around family and friends who haven’t yet received their shot or who are old or have compromised immune systems.
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