Polio was once among the most-feared diseases in the nation, capable of causing paralysis and even death. However, the very last polio case originating in the U.S. was documented in 1979—an achievement won through a sweeping vaccination program that began in 1955. Now, many people are wondering if they’re protected against the disease, or if they need to get an inactivated poliovirus vaccine (IVP) booster to ensure their safety. Read on to learn the four reasons why you might need a polio vaccine now, according to the Centers for Disease Control and Prevention (CDC).ae0fcc31ae342fd3a1346ebb1f342fcb READ THIS NEXT: Boosters Won’t Protect You Against Omicron If You’ve Done This, Study Finds. These days, most babies are given the polio vaccine soon after birth. The CDC recommends that children get four doses of polio vaccine. “They should get one dose at each of the following ages: 2 months old, 4 months old, 6 through 18 months old, and 4 through 6 years old,” their experts say. However, if you are an adult who has never been vaccinated against polio, it’s important to get vaccinated now. “Adults who have never been vaccinated against polio should get three doses of IPV: The first dose at any time, the second dose 1 to 2 months later; the third dose 6 to 12 months after the second,” says the CDC. Being partially vaccinated against polio also leaves you vulnerable. “Adults who have had one or two doses of polio vaccine in the past should get the remaining one or two doses,” the organization says. If you plan on traveling to an area where polio transmission poses a greater risk, you should ask your doctor if a booster shot is necessary, the CDC says. The organization points out that “five out of six World Health Organization regions are now certified wild poliovirus free: the African Region, the Americas, Europe, South East Asia and the Western Pacific,” however, there have been various reports of outbreaks which may be behind the CDC’s concern. (Pakistan and Afghanistan are the only two countries which have not yet eliminated indigenous wild polio.) “Travelers going to certain parts of Africa and Asia may be at risk for polio,” the CDC says. “Everyone should be up-to-date with their routine polio vaccination series. In addition, a one-time adult polio vaccine booster dose is recommended for previously vaccinated travelers to certain countries,” their experts advise. Not sure whether your particular destination is considered high risk? Use this handy tool from the CDC to find out, and discuss any questions you may have with your doctor. The CDC further adds that people who “are completely vaccinated but are at higher risk for contact with poliovirus should receive polio vaccination.” This specifically pertains to individuals who are “working in a laboratory or healthcare setting and handling specimens that might contain polioviruses.” For more health news sent directly to your inbox, sign up for our daily newsletter. Finally, the CDC says you should get a booster if “you are a healthcare worker treating patients who could have polio or have close contact with a person who could be infected with poliovirus.” While polio still remains exceedingly rare, it is very contagious and spreads through person-to-person contact. In particular, it is most often transmitted through direct oral contact with trace feces of an infected person (for instance, by touching a surface infected with fecal bacteria and then touching one’s mouth), or less often through the coughs or sneezes of an infected person. Since these two occurrences are more likely for those working in close proximity with healthcare patients, healthcare workers may benefit from getting an IPV booster.