Vaccinations: Myth vs. reality

Published: August, 2013

Don't let misinformation prevent you from getting the protection you need.

Vaccinations are a ritual of childhood, but they aren't just for kids. Even older adults need to arm themselves against preventable diseases, particularly ones like influenza and pneumonia. However, many adults aren't following the government's recommended vaccination schedule. A CDC report released in January found that vaccination rates are dangerously low among adults ages 65 and over. Only 62% of seniors received the pneumococcal vaccination, just over 50% got their tetanus vaccine, and a mere 15% were vaccinated against shingles.

Why are older adults so behind on their vaccinations? "First and foremost, I think vaccinations are not always on the top of the list of what to discuss at an office visit, both for the patient and for the health care provider," says Dr. Elisa Choi, an internal medicine and infectious disease specialist at Harvard Vanguard Medical Center. "I think there's also a lack of awareness about the need for vaccinations and how important they are," she adds. Also, some adults believe there are risks from vaccines.

Vaccine myth vs. truth

Harvard Women's Health Watch asked Dr. Choi to clear up some of the misconceptions about vaccine safety and effectiveness.

Myth: I'll catch the flu from the influenza vaccine.

Fact: "The injectable intramuscular flu vaccine is not a live vaccine, so it cannot, in any way, transmit the flu virus," stresses Dr. Choi. If you come down with a respiratory infection after getting the flu shot, it is likely caused by one of many other circulating viruses during flu season. Any minor fever or aches and pains after the shot are probably just a mild vaccine side effect.

Myth: The flu vaccine isn't effective in older adults.

Fact: You might have heard this from a CDC report out earlier this year, which found that last season's influenza A (H3N2) vaccine was only 9% effective in adults ages 65 and older. Yet the numbers don't tell the whole story. Each year, the flu vaccine formulation is based on predictions of which strains are most likely to circulate that coming season. Sometimes you may be exposed to a flu strain that doesn't match what you received in the vaccine, Dr. Choi says. Yet even if the strains don't match, you may get some benefit out of it. "It could make the infection less severe," she says. Because it is true that your immune response can wane with age, if you're 65 or older, you might want to ask your doctor about getting the high-dose flu vaccine (Fluzone high dose). Research suggests it produces a stronger immune response to the flu virus—although side effects such as injection site pain, fever, and muscle aches can be more pronounced.

Myth: Vaccines contain mercury, which could make me sick.

Fact: There have been some claims that the mercury-containing preservative, thimerosal, found in some vaccines is harmful. According to the CDC, there is no evidence that the low doses of thimerosal used in vaccines cause any harm. However, if you're still concerned, you can ask your doctor for a thimerosal-free flu vaccine.

Myth: Vaccines overload the immune system.

Fact: Most vaccines contain weakened or killed germs, which aren't strong enough to overwhelm the immune system. Considering that our immune system faces constant bombardment from germs in the environment, the small amount of bacteria and viruses we're exposed to in one vaccination can barely be considered an assault. In fact, vaccines strengthen the immune system by arming it against infectious agents.

Myth: Older adults no longer need to be vaccinated.

Fact: The opposite is actually true. With age, our immune system loses some of its protective ability. Meanwhile, we face an increasing number of chronic health conditions that can leave us more susceptible to infections. If you still aren't convinced that you need to get vaccinated, just look at the statistics. Eighty-five percent of all flu and pneumonia deaths in 2010 occurred among people ages 65 and older. Up to half of untreated people ages 60 and older with the shingles virus develop a painful complication called postherpetic neuralgia. "Vaccines really are one of the most effective and likely cost-effective ways to prevent these and other illnesses," Dr. Choi says.

Your vaccine checklist


How often you need it


Every year (in the fall)


(PPSV 23) pneumonia

Once for most people; you may need a second dose if you received your first dose before age 65, or if it has been five or more years since your last dose

Td and Tdap

Tetanus, diphtheria, and pertussis (whooping cough)

Get a tetanus booster dose every 10 years; get Tdap once in adulthood

Get a tetanus booster dose every 10 years; get Tdap once in adulthood

One dose (age 60 or older)

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