Of the nearly 3.2 million people completely vaccinated against COVID-19 in Illinois, 771 suffered from the disease anyway and 13 died, Illinois Department of Public Health officials report.
The number represents a small part of the total number of the disease, which is 1,296,381 known cases and 21,630 deaths among Illinois residents since the pandemic began.
Invoking privacy reasons, IDPH officials did not comment on whether the 13 who died had anything in common or had health problems that could have made the vaccine less effective.
Recently, researchers found that people who already had compromised immune systems or were taking strong immunosuppressive drugs were more susceptible to severe virus outcomes, even if they had been completely vaccinated.
“What we don’t know is the effectiveness of these vaccines in immunocompromised people,” said Dr. Jonathan Pinsky, medical director of infection control and prevention at Edward Hospital in Naperville. “We need to learn from these numbers and learn more about these cases to determine what the threat is.”
Nationwide, about 5,800 cases called “vaccine discoveries” have been reported to the US Centers for Disease Control and Prevention, according to data from a recent NPR report last week. Among these discovery cases, federal officials reported 74 deaths.
People are considered fully vaccinated when they exceed the final dose of vaccine by two weeks. In Illinois, 3,182,010 people meet this standard, nearly a quarter of the population, according to IDPH figures.
Those who became ill after being fully vaccinated represent less than 0.03% of that population, or one in 4,127 people who are completely vaccinated.
Of those vaccinated who became infected, 29 were sick enough to be hospitalized. This is a rate of one in 109,724 fully vaccinated people. Those who died were one in 244,770 people who were completely vaccinated.
Clinical trials of COVID-19 vaccines in the United States have shown at least 94% efficacy in preventing severe disease and death and approximately 80% efficacy in preventing COVID-19 infection.
Pinsky was concerned about how some of the cases found in fully vaccinated people were counted. Because the onset of symptoms usually occurs a few days after infection, someone who is diagnosed after two weeks may have been infected before the vaccine is fully effective.
“There is potential for fewer cases of discovery the further away you are from the second dose,” he said.
Overall, 166,885 additional doses of COVID-19 vaccines entered the arms of Illinois residents and workers on Thursday, IDPH officials reported. It is the second largest number of vaccines Illinois providers have administered in a single day.
Vaccine doses administered in Illinois are 7,779,290, with 3,453,704 in the suburban counties of Cook, DuPage, Kane, Lake, McHenry and Will.
IDPH reported 3,866 new cases of COVID-19 on Friday and another 21 deaths from respiratory disease.
Illinois hospitals treated 2,058 patients for COVID-19 on Thursday, of whom 468 were in intensive care.
The average positivity rate of the state’s seven-day case is 4.2%. He remained at that level for three consecutive days. A key indicator used to measure infection levels, case positivity tracks the percentage of new cases derived from a batch of tests.