Tackling the flu is tricky.
Influenza is widespread across the U.S. right now, according to data from the Centers for Disease Control and Prevention. The main culprit this season is the H3N2 flu, though others are also circulating.
H3N2 viruses are often linked to more severe illness and hospitalizations and more deaths, according to the CDC. It can hit children and adults over 65 especially hard, though stories of even healthy people falling sick and dying from influenza have sprouted up across the country.
Whenever a bad flu season hits, people condemn the shot and wonder if it's even worth getting. In good years, the vaccine can be about 40 to 60 percent effective. This year, the CDC estimates the vaccine will be in the range of 30 percent effective against the predominant H3 viruses.
Nonetheless, doctors and public health officials urge people to remember that some protection is better than none.
"This vaccine provides probably your best chance of protecting yourself against the flu, even though it's imperfect," said Dr. Paul Offit, professor of pediatrics at the Children's Hospital of Philadelphia. "There's no downside to the vaccine. It's a safe vaccine."
Creating a vaccine that matches the flu strains that eventually circulate can be challenging.
The U.S. Food and Drug Administration meets every February to choose what to put into the year's flu shot based on recommendations from the World Health Organization. They include three or four strains since multiple viral strains can circulate throughout the season.
The FDA may pick a good match, but the influenza virus often mutates, sometimes so much that the vaccine elicits immune responses that do not recognize it and therefore struggle to fight it.
Researchers and drug companies hope to one day create a vaccine that's more effective and lasts longer. Until then, doctors urge people to remember that flu can kill and that getting a flu shot is better than nothing, even at this point in the season.
Everyday practices can also help prevent the flu from spreading. Doctors recommend sneezing in one's elbow as opposed to hand. It may sound redundant, but they stress it's imperative to frequently wash one's hands.
"Every year, the flu is dangerous because of the ease of transmission," said Dr. Christopher Freer, director of emergency services for the Robert Wood Johnson Barnabas Health system, and chairman at the Saint Barnabas Medical Center in Livingston, New Jersey. "That's why we stress (hand-washing) over and over."