DEAR DR. ROACH: I am reading about an illness called acute flaccid myelitis that is baffling scientists. Isn’t this just polio renamed? — V.A.

ANSWER: Acute flaccid myelitis is indeed a medical mystery. The current outbreak absolutely is not caused by polio, however. Many people are referring to it as “polio-like” because it causes sudden neurological symptoms, especially weakness and especially in young children, just as polio did before the vaccine was adopted. However, the diagnosis of polio requires finding poliovirus, and the people affected in the current outbreak have been tested for, and do not have, poliovirus.

The last case of polio originating in the United States was in 1979. Vaccination for polio is still important, however, because it potentially can be brought by a traveler from one of the few areas where there is still wild polio.

There have been outbreaks of acute flaccid myelitis in the United States and Canada every fall for years; however, it seems to have be increasing in incidence since 2014. It remains a rare disease, on the order of one person per million per year.

There is a virus related to poliovirus called enterovirus D68 that is suspected to be one of several causes of acute flaccid myelitis. West Nile Virus is another suspected cause. The Centers for Disease Control and Prevention tests samples from affected children with the condition and has not consistently found a single cause.

There is no specific treatment for AFM, just as there is no treatment for polio when it affects the nerves. Supportive treatment in the early phase, and physical and occupational therapy during convalescence are the only accepted treatments. The prognosis is variable, with some children having excellent recoveries and others having more significant neurological impairment.

DEAR DR. ROACH: How effective is the flu vaccine for seniors 65 and over? — L.F.G.

ANSWER: Not as much as we’d like it to be, but still a lot better than none.

The flu vaccine is created every year based on the best available knowledge of circulating strains, and each year is a little different. The vaccine for 2017-2018 was estimated to be about 40 percent effective, meaning people who got the vaccine were 40 percent less likely to need to see a doctor for the flu. Over 900,000 people were hospitalized for the flu, 58 percent of them over 65, and the vast majority of the 80,000 people who died from the flu last year were seniors. Most of the deaths were in people who didn’t receive the vaccine.

Every year I hear people give me reasons not to take the flu shot. For those who say they have never taken the shot and never gotten the flu, I would respond that you need to get the flu only once to become seriously ill. To those who say it isn’t completely effective, I’d say reducing your risk by 40 percent is still worth a few minutes of time and a sore arm for a day, which is by far the most common adverse reaction. I’d also remind people of any age that by vaccinating themselves they are protecting others, including those who might not be able to survive an infection.

There are two special vaccines for seniors: the Fluzone high-dose and the Fluad vaccine, which contains an adjuvant, designed to increase the immune response. I recommend these if available for seniors, but you should not delay getting a flu vaccine if these are not available.

If you haven’t gotten the vaccine, it’s not too late. Please get it as soon as possible.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected] or send mail to 628 Virginia Dr., Orlando, FL 32803.

Dr. Roach