LITTLE ROCK, Ark. (AP) — The Arkansas Department of Health is studying whether the mumps vaccine is less effective against the type of mumps contracted by hundreds of people during the past three months of an outbreak first announced in August.
The department had counted nearly 1,600 confirmed or suspected cases of the mumps as of Nov. 22. Many of the cases have been in the northwestern part of the state, according to the Northwest Arkansas Democrat-Gazette (http://bit.ly/2gbfv7R ).
The U.S. Centers for Disease Control and Prevention said two doses of the mumps vaccine protect about 88 percent of people exposed to the virus. Arkansas epidemiologist Dr. Dirk Haselow said the type of mumps seen in Arkansas and other recent outbreaks in the country is genetically distinct from the type used to make the vaccine, but he said the vaccine is still helpful.
Mumps can often cause flu-like symptoms, such as fever and aches, along with swollen salivary glands on the side of the face, according to the CDC. A person can have the virus for close to a month before showing symptoms. Mumps is commonly spread by contact with an already infected person.
"What we've seen between 30 and 10 years ago is very low levels of mumps, just a few hundred cases in the United States per year," Haselow said. "But starting 10 years ago, there's been a resurgence, and we're seeing higher numbers and larger outbreaks, and more difficult to control outbreaks around the world but also within the United States."
Haselow said the state health department's study won't be finished until the current outbreak ends.