H1N1 flu activity in Salt Lake County has decreased for the third week in a row, Salt Lake Valley Health officials reported Monday.

However, despite the good news, continued caution is recommended.

"We want to continue to remind everyone to be vigilant," Salt Lake County Mayor Peter Corroon said. "There is no H1N1 crystal ball."

Dr. Dagmar Vitek of the Salt Lake Valley Health Department stressed that "seasonal influenza is unpredictable." She said examining past flu pandemics shows that some outbreaks have two waves and others had three, outlining their unpredictable nature.

H1N1's first wave in Salt Lake County went from May to July and caused 206 hospitalizations and two deaths. The current second wave of the flu, which started in September, has resulted in 212 hospitalizations and seven deaths. About 70 percent of those hospitalizations were for patients with underlying medical conditions.

"The second wave is comparable to the first," she said.

Vitek expects there will still be more hospitalizations and deaths from the flu, despite its downturn.

Gary Edwards, medical officer for the health department, said approximately 100,000 doses of the H1N1 vaccine have now been distributed in Salt Lake County. That means about 20 percent of the county is vaccinated. He said another 28,000 new doses will be available this week, and he expects 500,000 total doses to be available over time to the county.

"Even accepting the most optimistic predictions, Utahns should continue to get vaccinated as the vaccine becomes available," Corroon said.

He also recommends continued, frequent hand washing.

Edwards said that for the time being, the vaccinations will continue to be given only to the usual priority groups — pregnant women; household contacts of infants 6 months or younger; those ages 6 months to 24 years; those under age 65 with chronic medical conditions; health-care workers; and emergency-services personnel.

School absences due to the illness are also reported to be on the way down.

For more information, go to: www.slvhealth.org.

e-mail: lynn@desnews.com