It's that time of year again — time to roll up your sleeve for a flu vaccine. Doctors recommend everyone 6 months and older receive an annual flu shot.

No matter what side of the vaccine debate you're on, the facts are clear: Influenza is a huge public health issue. The flu kills an estimated 23,000 to 36,000 people each year in the United States and costs the nation billions in lost productivity and hospitalizations.

Some years, the vaccine works like a charm, but in others like 2014 the vaccine is a virtual fail. The reason centers on how the vaccine is created each year.

Pinpointing the three or four strains that are included in the annual flu vaccine is currently a game of chance. Scientists, health officials and pharmaceutical representatives are tasked with determining the best formulation by analyzing data such as the geography of each strain, outbreak timing and what strains hit hardest in previous years.

But what if that guessing game could be a thing of the past?

Recently published studies in Nature Medicine and Science show promise that there may one day be a one-stop shot. This so-called "universal vaccine" could protect against all flu strains. The research teams independently said they had mimicked a small portion of the flu virus known as a hemagglutinin stem, which helped them develop experimental vaccines that protected mice and ferrets from several types of flu.

Scientists like Barney Graham, deputy director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, and senior author of the Nature Medicine research paper, caution that this development is an early, but promising step.

In the meantime, Americans who are planning to get a flu shot this year have several choices. 2015 marks the first time flu shots will protect against four strains of influenza, instead of just three.

If you have a fear of needles, you might consider MedImmunes' FluMist. This quadrivalent nasal spray is approved for people ages 2 to 49. Because it's made from a live, weakened influenza virus, it's not currently recommended for anyone with a weakened immune system; people with diabetes or heart, kidney or lung conditions; pregnant or nursing women or anyone allergic to eggs.

If you fall into one of those exclusion categories, keep the faith. New research from the Johns Hopkins Bloomberg School of Public Health shows promise that a nasal flu vaccine could one day be approved for you, too.

CSL Behring makes a trivalent vaccine called Afluria that is approved for ages 5 and up and can be administered through a needle-free injection system called Stratis. Senior citizens should also consider the extra protection offered from Sanofi's High-Dose Fluzone. This vaccine stimulates the immune system to produce more antibodies against the flu.

A recent study shows protection from influenza drops after six months, meaning early fall is the best time to get vaccinated. If you still aren't convinced a flu shot is right for you, consider this added health benefit: The University of New South Wales suggested people who receive a flu vaccine are 30 percent less likely to have a heart attack.

Keep in mind that no matter which choice you make, it takes two weeks after vaccination to build up immunity. To determine the best option for your family, talk to a doctor or visit