“Flu is a serious illness,” she said. “Most people are going to feel very ill for a time and will get better without any bad things happening, but we can’t predict who is going to get super sick.”
Grohskopf said that those who are likely to get very sick and run the risk of complications, including hospitalization and death, are people 65 and older, very young children and people with chronic health problems such as asthma, heart disease, diabetes and those with weakened immune systems.
“But even younger, healthy people can get seriously ill,” she said.
The most common complication from flu is pneumonia, Grohskopf said.
In a typical flu season, flu complications — including pneumonia — send more than 200,000 people to the hospital. Death rates linked to flu vary from year-to-year, but have gone as high as 49,000 deaths in a year, the CDC says.
Pregnant women are also at increased risk from the flu, Grohskopf warned. And it’s vital that women with newborns get their flu shot to help protect their infants who can’t be vaccinated until they are at least 6 months old, she said.
How effective the vaccine is in preventing the flu depends on how good a match it is to the strains of flu virus circulating that year. Most years, the vaccine is between 40 to 60 percent effective, according to the CDC.
Last year, the vaccine offered little protection against the most common flu strain that circulated, an H3N2 virus, Grohskopf said.
That happened because the virus that experts predicted to be the predominate one changed, and the new H3N2 virus was not included in the vaccine, she explained.
This mismatch caused a severe flu season, especially for the very old and very young, and led to a record number of hospitalizations for flu among the elderly, Grohskopf said.
This year’s vaccine contains the new H3N2 strain. And although it’s too early to tell which strains will be predominant, Grohskopf added, it’s likely that last year’s H3N2 strain will still be the most common one around.
This year’s vaccine also includes two other strains that are expected to be around as well.
Plenty of vaccine should be available, Grohskopf said. Manufacturers are expected to produce 170 million to 179 million doses.
The vaccine is available in a variety of forms, including a shot, a nasal spray and an ultra-thin needle, called an intradermal flu vaccine. People allergic to eggs can get an egg-free vaccine, and seniors can get a high-dose vaccine, Grohskopf said.
The vaccine is safe, she said. “You can’t get the flu from a flu shot,” Grohskopf said. However, side effects from the flu vaccine may include fever and muscle aches, according to the CDC.
People can get their flu shot at their doctor’s office, at many pharmacies and even at work. It takes about two weeks after vaccination for the body to develop protection from the flu, according to the CDC.
October is the ideal time to get vaccinated, Grohskopf said. But it’s never too late, even after the flu season starts, she added.
“The important thing is to get the flu shot,” Grohskopf said.
Dr. Marc Siegel, an associate professor of medicine at NYU Langone Medical Center in New York City, called flu a community disease.
“It’s not all about you,” he said. “You want to create a ring of immunity, so don’t just do it for yourself, do it for other people around you.”
To help prevent flu, Siegel also advises staying home when you have the flu, washing your hands often and covering your cough.