UPDATE 6:59 P.M.: Measles has spread to Oregon.

Another five children have been diagnosed Friday with measles -- one of the largest jumps this week.

Nine other people are suspected of being infected, according to Clark County Public Health.

Of the 30 people with measles, 26 are unvaccinated. The remaining four are unsure whether they have been vaccinated or not.

The measles vaccine is 97 percent effective, and can reduce the risk of infection if gotten within 72 hours after exposure to the virus.

The majority of the confirmed cases are 10 years old or younger. The rest are between 11 and 18 years old, with only one adult.

The public health department also added one more location to a long list of places people might have been exposed to the measles virus: God Will Provide Church, 7321 NE 110th St. in Vancouver from 7 to 11 p.m. Friday, Jan. 18.

The highly contagious virus spreads through the air and can linger for up to two hours in an isolated space. People who have never received a measles vaccine are susceptible to the disease, which can be deadly.

State public health officials are urging people who have not received the vaccine to get it now -- as well as people who received the first dose but never the second, both of which are recommended in the first 10 years of life.

Clark County health officials are keeping both students and staff who cannot prove they have been vaccinated from the schools linked to the outbreak, most of which are in the Evergreen School District. Those who are excluded are also not supposed to enter other schools, child care centers or places with lots of people.

Even friends and families of students and staff at Evergreen High School and Orchards, Hearthwood and Image elementary schools are asked not to attend any events or games at the schools unless immunized. The Clark County health department has placed this restriction until Jan. 30 for most schools and Feb. 5 for Orchards.

To further limit the spread of the virus, health officials ask that people who think they might have measles call their doctor or health care provider before visiting a hospital or doctor’s office.

Washington State Department of Health keeps track of residents’ immunization status so people can see if they need shots.

Clark County Public Health also now maintains a daily call center for questions about the outbreak at 360-397-8021.