Following the relentless increase in H1N1 influenza in King County since late August, cases of H1N1 influenza are now decreasing – at least temporarily – from a peak in late October. Although the future course of the epidemic remains uncertain, based on the experience of the H1N1 outbreak during the southern hemisphere’s flu season, illness would be expected to continue to spread locally among those who are not immune during the coming weeks.

“The break in the rising rate of infection gives us more time to vaccinate people who don’t yet have immunity, especially given the slow start to vaccinations because of the national vaccine shortage,” Dr. David Fleming said, director of Public Health – Seattle & King County. “Availability of vaccine will continue to improve in coming weeks, and we encourage people who are recommended to receive vaccine to seek it out. Eventually, everyone who wants vaccine will have an opportunity to get it.”

While down from the previous two weeks, emergency departments continue to see an elevated number of visits for flu-like illness similar to spring outbreak levels. Recent hospitalizations for H1N1, while lower in number than in October, still remain above the levels seen in the spring.

An estimated 190,000 people in King County who are at high-risk for complications have already been vaccinated for H1N1 influenza. Additionally, an estimated 132,000 people have had H1N1 influenza between April and Oct. 17, 2009. These factors may be contributing to the slowing of infection rates overall, yet more vaccination will help to protect the community and those most at risk.

People who are recommended to receive H1N1 vaccine should continue to seek it. Vaccine supply is gradually improving each week, and it is expected that eventually there will be enough vaccine in King County for anyone who wants it.

Given delays in supply, H1N1 vaccine is presently reserved for people in priority groups:

• pregnant women;

• people who live with or care for children younger than 6 months of age;

• people between the ages of 6 months and 24 years old;

• people between 25 through 64 years of age with chronic health conditions or weakened immune systems and

• healthcare and emergency workers

Given the limited supply, Public Health’s current focus is on getting most of the available vaccine to health care providers, so that they can vaccinate patients who are most at risk. To provide another option for people prioritized to receive H1N1 vaccine, Public Health is allocating a limited portion of vaccine supplies for distribution more widely through pharmacies.

Visit the Public Health H1N1 influenza Web site

for updates on vaccine availability in the community or call the Flu Hotline at 877-903-KING (5464), which is staffed with operators to answer questions from King County residents about H1N1 influenza. Hours of operation with operators are 9 a.m. to 5 p.m. weekdays, with special 24-hour nurse line service extended over this weekend for people with flu seeking medical care advice. Recorded information is available 24 hours a day.

Flu illness activity

• The approximate daily numbers of visits for flu-like illness to King County emergency departments have fallen by half from a high of over 250 visits per day, but remain significantly elevated and are now in a range similar to that seen during the spring H1N1 outbreak. Similarly, the proportion of patients seen in emergency departments with flu-like illness has decreased from a peak of 10 percent to 5 percent this week.

* Hospitalizations for H1N1 have been decreasing for the past few weeks, but they are still above the peak of the spring outbreak.