OSU's campus

Oregon State University's campus in Corvallis. The university held a vaccination clinic in early March following several instances of meningococcal disease.

Oregon State University hosted a two-day mass vaccination in Corvallis last week to boost immunity on campus to a strain of meningococcal disease that had sickened three students in the past four months.

Officials said Monday the clinic was a success - more than 1,800 students were vaccinated -- but OSU is still not certain how many of the estimated 7,000 students considered at the highest risk to contract the disease have received the vaccine.

"This was an excellent start in our efforts to vaccinate at-risk students and protect community health," Steve Clark, OSU's spokesman, said in a statement. "We're going to continue our communication and outreach to students who have not yet been vaccinated and make sure they, and their families understand the importance of this two-part vaccine regimen, and that there's still time to be vaccinated."

An additional 650 students were vaccinated against the type b meningococcal disease strain dating back to last fall.

Clark said the school knows for certain that some 35 percent of the 7,000 students who are at higher risk have received the vaccine. Meningitis is a potentially lethal infection of the brain and spinal cord.

Students deemed at elevated risk are younger than 25, live on campus and are members or attend fraternity or sorority groups.

OSU students are required to take a meningococcal vaccine before being admitted to the university, but that vaccine covers four different strains of the potentially deadly disease. The required vaccine does not protect students against the strain which sickened three students in separate incidents.

Meningococcal disease can be transmitted by contact with discharges of the nose and throat, including by sneezing or kissing. The disease can also be transmitted by sharing utensils and other direct physical contact.

Two students contracted the meningitis strain in November, and a third was reported two weeks ago.

In 2015, a University of Oregon student died because of meningococcemia, a blood infection. Some 10,000 UO students were subsequently vaccinated.

-- Andrew Theen

atheen@oregonian.com

503-294-4026

@andrewtheen