Do you remember the 2009 flu season?
H1N1 was the primary strain of this influenza, commonly referred to as “swine flu.” It was a unique combination virus that had never before been documented in people.
In an interesting twist of good news after a dramatic season, the Centers for Disease Control and Prevention said that fear of the pandemic-level flu helped to boost vaccination rates to record levels across the country.
This flu season, the H1N1 virus is back, but it’s not exactly causing a line for flu shots at the pharmacy.
“This year’s flu activity has predominantly been H1N1, the same strain that caused pandemic in 2009, and it hasn’t mutated substantially,” said Dr. Tom Frieden, director of the CDC in a press call Thursday. “It’s back this year and hitting younger people hard.”
Dr. Anne Schuchat, the assistant U.S. surgeon general and director of the National Center for Immunization and Respiratory Disease, said in the same press call that this year they don’t want people to wait for a tragic flu-related death story to incentivize them to get vaccinated.
Only one-third of adults ages 18 to 64 had been vaccinated by November, a month into the 2013-2014 flu season. This population, which is least likely to be vaccinated, has had the majority (61 percent) of flu-related hospitalizations so far, a figure that’s climbing from previous years, according to the CDC report released this week.
The 2012-2013 flu season, which caused hundreds of thousands of hospitalizations nationwide and resulted in a public health emergency in the city of Boston, had 35 percent of hospitalizations from this age group. During the 2009-2010 H1N1 flu pandemic, 56 percent of hospitalizations were from the 18 to 64-year-old population.
Dr. Frieden said that low vaccination rates is one of the reasons we’re seeing a much higher proportion of hospitalizations and deaths among 18 to 64 year olds than usual. “We’re particularly seeing hospitalizations and deaths with people with underlying medical conditions such as obesity, diabetes, lung cancer, and asthma,” he said.
The good news is that the influenza vaccine for the 2013-2014 flu season is a strong match for the 2009 flu strain. The CDC report says this year’s flu vaccine reduced the percentage of people visiting the doctor to get a tested confirmation of the flu by 61 percent.
“This year the vaccine gave significant protection to all age groups,” said Dr. Schuchat. “This season is not over though and things could change.”
Somewhat predictably, we are taking better care of our children than we take care of ourselves. Children are vaccinated at the highest rate in decades, at around 60 percent annually. The vaccination rate for people ages 18 to 64 is around 30 percent. CDC officials said that they attribute this to a more effective public health campaign that enlists pediatricians and parents in the vaccination effort.
For children under two years old, the flu vaccination rate now hovers around 80 percent, according to the CDC officials.
“Parents got a wake up call in 2009,” said Dr. Schuchat, referring to the 2009 H1N1 pandemic that caused 477 pediatric deaths. “We’ve seen tremendous progress in influenza vaccinations for children since then. But it’s a new recommendation that every adult get a vaccine every year.”
There is no exact tally of the deaths caused by the flu so far this year. Boston reported its first flu-related death of the 2013-2014 flu season in January.
Dr. Anita Barry, director of the Infectious Disease Bureau at the Boston Public Health Commission, said in an interview that the national statistics reflect what we’re seeing in the 713 confirmed flu cases so far in Boston.
CDC officials continue to emphasize that for people of any age, vaccination is the single most important thing to protect yourself against the flu.
Chelsea Rice is a health content producer for Boston.com. Email her at email@example.com. Follow her on Twitter @ChelseaRice.