Flu vaccine goes unused even by high-risk groups

HCWs report lower vaccination rates this year

With only one-third of priority groups receiving the influenza vaccine, the Centers for Disease Control and Prevention (CDC) urged midseason vaccination and expanded the groups eligible for vaccination.

The shortage kept many people from getting their annual flu vaccine — apparently including many who are at risk for complications from influenza.

The CDC reported that 75% of the vaccine supply went to those in priority groups, even taking into account the 33 million doses that were released before the suspension of Chiron’s license — and loss of 48 million doses — was announced in October.

But by mid-December, only 34% of high priority groups had been vaccinated, said CDC director Julie L. Gerberding, MD. The low coverage of vaccination included health care workers. In a survey reported in the CDC’s Morbidity and Mortality Weekly Report, 49% of health care workers reported receiving the vaccine last year, while only 34% received it this year.1

"That coverage is lower than we would have seen at midflu season last year," she said in a press conference.

"About 50% of people in high-risk groups have not gone out to get vaccinated. They’re stepping aside, and that is not what we want them to be doing," Gerberding explained.

Vaccine not needed?

The most common reason health care workers said they did not receive the vaccine: They felt it wasn’t needed (27%). Another 18.5% of health care workers said they tried but could not get the vaccine.

The survey included a variety of hospital personnel, including nurses, physicians, laboratory workers, and office receptionists. Health care workers with direct patient care are in the priority group for the vaccine.

Health care workers need a focused message that stresses the importance of the vaccine in preventing spread to high-risk patients, notes William Schaffner, MD, chair of the department of preventive medicine at Vanderbilt University in Nashville, TN. "It’s only this year that we have begun a sustained educational campaign to let them know the main reason we are asking health care providers to become immunized is so they won’t infect their patients," he says. "In the past, we have assumed health care workers know this, and they don’t."

With additional vaccine available, the Advisory Committee on Immunization Practices (ACIP) voted to broaden the priority groups to include people ages 50 to 64 and out-of-home caregivers and household contacts of people in high-risk groups.

The high-risk groups include people 65 or older, children younger than 2 years of age, pregnant women, and people of any age who have certain underlying health conditions such as heart or lung disease, transplant recipients, or people with AIDS. ACIP is an advisory panel to CDC.

As of mid-December, Aventis still had 2.6 million doses available. CDC purchased an additional 1.2 million doses of vaccine from GlaxoSmithKline, which was manufactured in Europe and will be available under an investigation new drug status. People receiving the vaccine will need to sign a consent. An additional 2.8 million doses may be available from that same source, if necessary, Gerberding said.

"If a worst-case scenario occurs and we have a dramatic up tick in the influenza late in the season, then we’ve got some extra doses there that we can utilize to protect the people who need it the most," she noted.

Meanwhile, it still is unclear whether Chiron will be able to produce vaccine for next year’s supply. Restrictions on who can receive the vaccine may need to be extended.

"If the worst case happens and we don’t have the Chiron vaccine, we’ll be working with the other international suppliers to try to get licensure of their product," Gerberding added. "We’ll be working with domestic suppliers to see what, if anything, we as a government can do to scale up their production. And we’ll be planning on our immunization programs to take under consideration whatever contingencies are necessary to meet the demands of the high-priority populations."

Reference

1. Centers for Disease Control and Prevention. Estimated influenza vaccination coverage among adults and children — United States, September 1-November 30, 2004. MMWR 2004; 53:1,147-1,153.