"The most prevalent strain going around matches the vaccine very well," Ratard said.
Some people will get ill even after getting the vaccine because they were exposed before the vaccine could create an immune response, they got a strain of flu not covered by the shot or another virus or germ entirely, or because their bodies don't respond as strongly to the vaccine.
"For people 65 years and older, there's a high-dose flu vaccine that may be more effective," Dodds said.
People who become ill after vaccination are likely to have a less severe illness than they would have without the shot.
In any case, try to avoid spreading whatever you have. "If you're sick, stay home," Dodds said. "Try to give yourself at least 24 hours from the end of fever before you get back to work or around other individuals. And also remember to see your doctor if you get sick, because there are antiviral medicines that can help lessen the severity and shorten the disease."
In each state about 600 people die each year from flu-like illnesses.