The worst may be over for the flu season that hit earlier than expected this season. Influenza levels in Illinois are no longer “widespread,” according to the Centers for Disease Control and Prevention’s most recent data.
Illinois has experienced a high level of influenza activity for the last six weeks, but the CDC reported Friday that numbers have been gradually decreasing over the last month. The decrease has moved Illinois out of the widespread category.
The CDC reported that depending on the severity of the season, between 3,000 and 50,000 people die in the United States each year from influenza-related illnesses. Melaney Arnold from the Illinois Department of Public Health said that there have been 98 flu-related deaths in Illinois this year, with 651 total hospitalizations.
According to the department’s most recent data released last week, outpatient visits for influenza-like illness is now 2.6 percent, which is a huge decrease from the 3.3 percent the previous week. In addition, Illinois’ influenza activity is now being monitored and reported on a regional scale, instead of a widespread basis.
This flu season started in early December, which is earlier than previous years, according to the CDC. Despite the early start, Dr. Thomas Frieden, the CDC's director, said in a congressional hearing that this season did not reach "pandemic proportions."
Curtis Allen, a spokesman for the CDC, said 22 states are still reporting a widespread influenza activity level — a decrease from 31 states in the previous week and 38 states the week before.
“Overall it’s been a moderate-to-severe season,” Allen said. “Currently the influenza activity still persists but it’s going down at a steady pace.”
He said the number of deaths and hospitalizations are similar to the results of previous years that had a H3N2 strain circulating. The H3N2 strain, which is also known as influenza A, tends to be more severe. The CDC reported that as of Tuesday, there have been 78 pediatric deaths this season. Typically this number averages about 100 each year and Allen said unfortunately this was not a surprising result. He added that there was one thing the CDC did not expect this season: The vaccine’s effectiveness in different age groups.
Overall the vaccine was 56 percent effective, Allen said. The CDC reported that it was less effective against the influenza A strain — protecting 47 percent — and it protected 67 percent of those who received the vaccine from influenza B.
“Those are the typical numbers we’re going to see when the vaccine is well-matched with the strains being circulated,” he said. “But we did experience the biggest change in those 65 and older.”
According to the CDC, only 9 percent of people 65 years or older were protected from influenza A after receiving the vaccine, and about 90 percent of flu-related deaths this year were those in this same age range.
Allen said there are two important factors that determine the vaccine’s effectiveness: One is whether or not the vaccination is a close enough match to the strains circulating. The second is the age of the person receiving the vaccine and any chronic health problems they may have. He said that studies have shown that both age and health can diminish the body’s response to the vaccine and make someone more vulnerable for infection or further complications.
Even though the benefits for the vaccine vary for different age groups, Allen said it does not mean the public should lose faith in its overall effectiveness. It can still help to prevent the illness from spreading to others.
“It’s the best we have at the moment,” he said. “And because it’s the best we have, the best thing you can do is get vaccinated if you’re living with someone that’s very young or over 65.
“Bottom line is we need to advance the research on influenza vaccinations but we’re just not there yet.”