Healthy Living

Flu Shots: What, Why and When

Oct. 2, 2018

person getting ready to get a flu shotFlu season is rapidly approaching and ads for flu shots are popping up everywhere. Should you get one? Will it work? UR Medicine vaccine expert Dr. Ann Falsey explains what's new this year and why it's important to get a flu shot every year.

Health Matters: Will this year's flu shot be effective? Should I get it this year?

Falsey: Flu shots aren't perfectly effective for every person every year, but they're our best chance to fight and prevent the spread of illness. The vaccine is essentially risk free; some people may get a sore arm from the shot or feel achy afterwards, but that is much better than coming down with the flu.

Health Matters: When is the ideal time to get a flu shot?

Falsey: The best time to get the flu shot is when it becomes available. The flu usually peaks in December, January and February, so you might think it's best to wait until the beginning of November to get vaccinated so that you'll have the best protection in the height of flu season. In reality, you don't want to pass up a chance to get vaccinated and then never get around to getting a flu shot. Bottom line: Don't wait because you think it is better to get the shot later.

Health Matters: How many different types of flu vaccines are there? Which one should I get?

Falsey: There are several types of vaccines available this year. What's most important is that you get a vaccine; the specific type is less important.

  • Quadrivalent vaccine: This is the regular flu shot that protects against four strains of flu—two strains of A virus and two of the B virus. Most manufacturers are now making this form to maximize protection.
  • Trivalent vaccine: This is the regular flu shot that protects against three strains of flu. This has been the gold standard for flu prevention but it will likely fall out of favor compared to the quadrivalent version.
  • High-dose vaccine: This is available for people over the age of 65, whose immune systems might need an extra boost to produce antibodies against the flu. 
  • Egg-free vaccine: For people who are allergic to eggs, there are two different kinds of vaccines that aren’t made in eggs; one is made in insect cells and another is made in cell culture.
  • Adjuvanted vaccine: This is a “juiced up” version of the vaccine and stimulates antibodies for people 65 and older.
  • Nasal spray vaccine: Flu Mist, a favorite option for kids, is back this year after a two-season hiatus. It was taken off the market after studies showed it provided limited protection. But, changes were made to the vaccine and new research suggests it should be an effective option this year.

Vaccine experts in the Infectious Diseases Division are always looking for healthy volunteers to participate in clinical studies of flu vaccines. If you are interested, call 585-273-3990 or email


Infectious disease specialist Dr. Ann Falsey


Ann R. Falsey, M.D., is a professor of Medicine, Infectious Diseases who conducts research and treats patients at the University of Rochester Medical Center and Rochester General Hospital.