It’s that time of year again – when flu shot signs begin decorating the windows of schools, pharmacies and hospitals as reliably as holiday sale advertisements. For passers-by asking, “Should I get one?” medical experts again have a definitive answer: “Yes!”
This month, officials at the Centers for Disease Control and Prevention are spreading the word about the current flu vaccine, meant to be the most effective protection against the messy, exhausting and often debilitating illness caused by the influenza virus.
Their job is slightly more difficult this year, given the relative ineffectiveness of last year’s flu shot and the growing public hesitance around vaccination. While some parents fear vaccinations cause autism spectrum disorder and other developmental conditions, there is no scientific evidence to support those theories.
Last year, the U.S. saw the highest flu-related hospitalization rate among seniors ever documented. Also, 145 children were documented to have died from influenza last year, compared with 105 the year before. Seniors, children, pregnant women and individuals with weak immune systems are the most likely to contract influenza virus.
In a recent press conference, CDC Director Tom Frieden urged everyone, regardless of age, health status or views on vaccination in general, to get the flu vaccine.
Here are the basics on this year’s shot:
How does the CDC design the flu vaccine?
Each year, CDC officials track which strains of influenza virus are spreading around the world, particularly in the Southern Hemisphere, as those are typically the same strains that show up in the United States the following winter. Working from global data, they create a live virus using weakened forms of the most prevalent strains.
Sometimes, as was the case last year, new influenza strains emerge after the U.S. vaccine has been created. In 2014, officials designed a vaccine against H1N1, which they believed would be the predominant strain. The virus that actually infected most individuals was an H3N2, which the flu vaccine did not protect against.
How effective was the flu vaccine last year?
In a typical year, the flu vaccine prevents flu in 50 to 60 percent of individuals who get vaccinated. That’s much less effective than vaccines for other viruses, but much more effective than any other existing method of preventing the flu, Frieden said.
Last year, the flu vaccine was only 13 percent effective against the H3N2 strain, though it was 50 to 60 percent effective against H1N1 and B strains that were also circulating but in smaller quantities.
This year’s vaccine has been updated to better match the H3N2 strain, which officials have predicted will return this year.
What type of vaccine is appropriate?
The CDC recommends that everyone over 6 months of age get vaccinated for influenza. While most people need only one dose of flu vaccine each season, children under the age of 9 may require two doses.
There are two main types of flu vaccine: the injection and the FluMist nasal spray.
The injection: May be given to healthy people over 6 months of age. It can safely be given at the same time as other vaccines. It’s made from a killed form of the flu virus and doesn’t cause flu, although it may provoke mild symptoms such as arm soreness, fatigue or fever. It is not recommended for people with life-threatening allergies or Guillain-Barré syndrome.
The nasal spray: May be given to healthy, non-pregnant people ages 2 through 49, and is recommended for children ages 2 through 8 when available. Made from weakened flu virus, it may cause runny nose, headache or sore throat. It is not recommended for people with severe allergies, weakened immune systems or numerous other conditions.
Are we meeting public health goals for influenza immunization?
Last year, about half of the U.S. population got vaccinated, according to the CDC. There were increases in vaccination coverage among adults, pregnant women, and among health care providers, particularly pharmacists, doctors and nurses.
Still, some trends concern the experts, Frieden said. Vaccination rates among young adults and middle-aged people are low, and only half of pregnant women got vaccinated last year. It’s especially important that people who work in long-term care facilities, such as nursing homes, receive vaccinations so they don’t infect vulnerable residents.