Your Guide To Adult Vaccines
En español | After decades of decline, the number of hepatitis A cases in the U.S. has exploded in recent years, increasing 1,325 percent from 2015 to 2019, according to the Centers for Disease Control and Prevention (CDC).
This highly contagious liver disease can be passed from an infected person or from contaminated food. In recent years there have been hepatitis A outbreaks linked to tainted blackberries sold in grocery stores, imported strawberries used in smoothies at Tropical Smoothie Café locations nationwide and everything from pizza to salads served at major restaurant chains.
Although children are now routinely vaccinated against hepatitis A, most older adults aren't protected, even though they are at higher risk of complications. Only 6.1 percent of adults age 50 and older have received the vaccine, according to the CDC.
Hepatitis A is found in the stool and blood of infected people. It spreads when someone unknowingly ingests even a microscopic amount through food, water or the environment, says Jeff Goad, a pharmacist and public health expert who is vice president of the National Foundation of Infectious Diseases. The illness can also be spread through sexual contact.
In 2019 alone, 31 states reported over 18,846 hepatitis A cases and more than 225 people died from the disease.
Although national numbers for 2020 aren’t yet available, the disease continued to spread in some areas during the COVID-19 pandemic. For instance, North Carolina health officials issued an alert in April 2021 about a marked increase in hepatitis A cases in 2020 and 2021, with more than 60 percent of patients requiring hospitalization.
Much of the spread happens in homeless communities, with outbreaks reported in cities including San Diego, Los Angeles, Miami and Philadelphia, and in Florida and Kentucky.
But the number of foodborne cases has also grown, Goad says, as the United States increasingly relies on imported fruits and vegetables. “For better or worse, our country is very dependent on other countries for our produce, including countries where there are outbreaks,” he says.
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Restaurant outbreaks can be caused by tainted fruits and vegetables or an infected employee who doesn’t appropriately wash his hands, Goad says.
Symptoms of hepatitis A include yellow skin or eyes, fever, loss of appetite, dark-colored urine or light-colored stools, diarrhea, nausea, stomach pain and fatigue.
If you learn that you've been exposed to hepatitis A, either through personal contact with someone or through a foodborne outbreak, you can prevent infection by getting the vaccine or an immunoglobulin injection within two weeks of exposure.
About 61 percent of infected people are hospitalized, according to the CDC. The risk of complications, liver failure and death is higher in older adults.
Who should get the shot — and side effects to know
The agency routinely recommends the vaccine for the following groups who are more susceptible to the disease or its spread, including anyone with chronic liver disease, men who have sex with other men, homeless populations and those who use illegal drugs. It's also recommended for those in group homes or day care facilities for the developmentally disabled.
But anyone can request and receive the vaccine, and doctors say there's little downside — other than a few temporary side effects of the shot, which include: swelling, tenderness, redness warmth or a hard lump at the injection site, as well as low fever, nausea, loss of appetite and headache.
Medha Munshi, M.D., director of the Joslin Geriatric Diabetes Program at Beth Israel Deaconess Medical Center and an associate professor at Harvard Medical School, says she offers the vaccine to patients but doesn't push it because there are usually other, more pressing medical concerns.
"It's a matter a priorities,” she explains. “There are other things to push. When we talk about the flu or shingles or Tdap [tetanus, diphtheria and pertussis], it's clear that everyone should have it. The risk of hep A is not as high, compared to other things.”
John Scott, M.D., an infectious disease specialist and director of the Hepatitis and Liver Clinic at Harborview Medical Center in Seattle, says getting the vaccine is especially important if you're traveling to a country with a high transmission rate.
"If you're taking a cruise down to Mexico, for example, that's a good reason to get vaccinated,” he says. “Even though the CDC recommends two doses six months apart, if you don't have time to do that, the first dose does a good job providing protection.”
What to know about the hepatitis A vaccine
Who needs it: adults who have a chronic liver condition or who plan to travel to a country where hepatitis A virus transmission is common. (To check, go to cdc.gov/travel, click on the country you're visiting and then Vaccines and Medicines.) Other groups at risk include men who have sex with other men, people who use illegal drugs, people who were recently incarcerated and those who aren't in a stable housing situation.
How often: once, but given in two doses at least six months apart. There is also a combination vaccine for both hepatitis A and B, called Twinrix, which is given in three doses over six months.
Why you need it: The number of cases in the U.S. has soared since 2014, with outbreaks in more than 30 states. While the CDC does not routinely recommend the vaccine for all adults, it says the shot can be given to “any person wishing to obtain immunity.”
Editor’s note: This article was published on Oct. 20, 2020. It was updated in September 2021 with new information.
Michelle Crouch is a contributing writer who has covered health and personal finance for some of the nation’s top consumer publications. Her work has appeared in Reader’s Digest, Real Simple, Prevention, The Washington Post and The New York Times.