As an adult, do you skip vaccines because you don’t think you still need them? According to a 2018 report from the Centers for Disease Control and Prevention (CDC), "many adults in the United States have not received recommended vaccinations."

“Each year, at least 30,000 people die from complications related to vaccine-preventable diseases,” says Marvin M. Lipman, M.D., Consumer Reports’ chief medical adviser. “Getting the right shots doesn’t guarantee that you won’t get sick, but it will significantly improve your odds.”

Here, answers to four common questions about adult vaccines.

I Was Fully Vaccinated as a Child. Why Do I Need More Vaccines Now?

Over time you may lose the ability to fend off diseases you were vaccinated against earlier. Some adult vaccines, such as those for mumps and tetanus, are boosters, building your immunity against those illnesses. Others protect against diseases that are more common in adulthood, such as shingles.

MORE ON VACCINES

According to the CDC, all adults should have an annual flu shot; a Td booster every 10 years to ward off tetanus and diphtheria; two shots of the Shingrix vaccine (with two to six months between doses) at age 50 to guard against shingles; and two pneumococcal vaccines, one year apart beginning at age 65, to protect against pneumonia.

“If you’re unsure if your shots are up to date, it’s best to get vaccinated,” Lipman says. “It’s better to get revaccinated than go without protection.”

Are Vaccines Less Effective for Me Now That I’m Older?

Probably. Vaccines work by tricking the immune system into producing disease-fighting proteins called antibodies.

“Older people don’t form antibodies as well as younger people, so the older you are, the less effective that vaccine is going to be,” Lipman explains.

But even if the adult vaccines you get are only 50 percent effective in preventing disease, he says, “you will likely have a milder case if you do get sick.” That’s important because as we age, illnesses can hit harder and lead to more complications

Every Time I Have a Flu Shot I Feel Lousy Afterward. Is the Shot Giving Me the Flu?

No. A flu shot might cause mild side effects such as a sore arm, redness and swelling at the injection site, and even a slight fever, but it’s unlikely that any vaccine will really make you sick.

“To put to rest an old myth,” says William Schaffner, M.D., a professor at the Vanderbilt University School of Medicine and consultant to the CDC’s Advisory Committee on Immunization Practices, “you cannot get flu from the flu vaccine.”

If you do get sick after being vaccinated, it’s probably a coincidence, Schaffner says. Most flu shots are given from September to December to prepare you for peak flu season in the winter and early spring.

Once in a while, though, a vaccine does cause serious side effects. For example, according to the CDC, about one in a million people develops Guillain-Barré syndrome after a flu shot. That can cause temporary muscle weakness and tingling, breathing difficulties, and in rare cases, permanent paralysis. But a large 2013 study found that the flu itself is linked to a higher risk of Guillain-Barré syndrome than the vaccine.

Do I Really Need a Shingles Vaccine? If So, When?

If you're 50 or older, it's smart to get vaccinated against shingles unless you have a medical reason not to get the shot.

A shingles infection, which occurs when a dormant chickenpox virus “wakes up,” can cause a burning, stinging rash and nerve pain (postherpetic neuralgia, or PHN) that can linger long after the rash subsides.

In January 2018 the CDC recommended that all adults age 50 and over get a new vaccine (Shingrix) that has been shown to prevent shingles and its complications more effectively than an older vaccine known as Zostavax.

The new vaccine, which requires two doses to be given two to six months apart, appears to offer 97 percent protection against shingles in people in their 50s and 60s, and roughly 91 percent for those in their 70s and 80s.

Editor's Note: This article first appeared in the September 2015 issue of Consumer Reports On Health. It was updated in 2017 and 2018.