BALTIMORE COUNTY, Md. (WJZ) — A third confirmed case of measles in Maryland came this week as outbreak spiked nationwide.

Health officials are on high alert and encouraging those who have not had the vaccine to get it immediately.

READ MORE: Crews Battling 2-Alarm Fire At Reisterstown Apartment Building

Third Measles Case Confirmed In Maryland, Health Officials Name Two New Locations Of Exposure

The Maryland Department of Health sent 1,200 doses to a Jewish girls’ school in Baltimore, creating a pop-up free clinic Wednesday.

“I need a vaccine, just to be on the safe side,” said David Dannbaum, Baltimore resident.

“I was expecting, like, a two-hour wait. I brought all this work to do,” said Miriam Lando, Baltimore resident.

Last Friday, people did wait in line for hours to get the vaccine, at the first of the two clinics.

Health Officials Hold Vaccination Clinic Following Baltimore Co. Measles Case, Warning Public To Remain On High Alert

READ MORE: Hundreds Of Saliva Samples Expire From Ripken Stadium COVID-19 Testing Site

Not far from a Pikesville medical office, where health officials warn patients may have been exposed to measles on April 2.

Symptoms take two weeks to set in, and while they have confirmed a second case, the two patients are in some way connected to the same household- and they picked up the illness outside of Maryland in an area with an ongoing outbreak.

“You could walk into a room after someone who has been infected has left the room and still get the disease,” said Dr. Gregory W. Branch.

Branch, the director of health in Baltimore County, said it is highly contagious.

Which has become evident across the country- with another 90 cases in the last week, bringing the nationwide number of 555 patients.

Dr. Branch said the bottom line is getting the vaccination.

The second clinic shut down at 3 p.m. Wednesday. There is no word yet on if there will be another.

MORE NEWS: Marilyn Mosby’s Supporters Vow To Fight Following Federal Charges, Lawyer Asks For Quick Trial

Follow @CBSBaltimore on Twitter and like WJZ-TV | CBS Baltimore on Facebook