BETHESDA, MD 30 August 2010—Starting this flu season, all Americans age six months or older without a contraindication are advised to get vaccinated against influenza annually, but the dosing schedule for young children is a complex legacy of the pandemic H1N1 influenza virus that emerged last spring.
The Centers for Disease Control and Prevention (CDC) recommends a single annual influenza vaccination for children over age 8 years and adults.
Influenza Resources For important information about influenza, visit the Stop the flu—it starts with you! resource center and the ASHP Foundation`s Pandemic Readiness and Emergency Preparedness Resource Center.
Children 6 months through 8 years of age who have never been vaccinated against seasonal influenza should receive two doses of trivalent vaccine administered at least 28 days apart, according to CDC. If only one trivalent vaccine dose was administered during the young child`s first immunization year, two doses should be given the following year and one dose annually thereafter.
But children 6 months through 8 years of age who did not receive any doses of monovalent H1N1 vaccine last season need two doses of this season`s trivalent vaccine, which contains a pandemic H1N1 strain. Thus, a child who received two doses of trivalent vaccine last year but was not vaccinated against H1N1 should receive two doses of trivalent vaccine again this season—for four vaccinations over two seasons.
A child who received one dose of monovalent H1N1 vaccine but is otherwise on schedule for influenza vaccination requires only one dose of the 2010–11 trivalent vaccine.
The World Health Organization on August 10 declared an end to the H1N1 pandemic, but the H1N1 virus is expected to continue to circulate along with seasonal influenza virus strains.
Brett Crisp, clinical pharmacy manager for pediatrics at UNC Health Care in Chapel Hill, North Carolina, said his health system will rely on its computer system and staff diligence to keep track of young patients` influenza vaccination status.
"We really take a proactive approach to make sure our kids are vaccinated the way they should be," Crisp said. "Our pharmacists here in the inpatient setting do a really good job of monitoring and making sure that kids have gotten their vaccines up to date, [and] on discharge, the nurses do a pretty good job of making sure that everything is up to date."
He said the state-owned health system`s inpatient and outpatient records are linked, which helps keep vaccinations on schedule. To ensure accuracy, vaccination records for influenza and other diseases are routinely verified with pediatricians` offices and the state health department, Crisp said.
Crisp said one of his challenges last season was obtaining influenza vaccines to cover a range of patient ages. Some available products were indicated in children up to age 3 years, and others were labeled for people age 4 years or older, limiting the options for children in the age gap.
"We felt a little bit of a supply issue about halfway through" the season, he said. "So I think this year, we`re trying to diversify the products that we have to make certain that we don`t run into that issue again."
Influenza virus vaccine manufacturers in late July and early August began shipping vaccines for the 2010–11 flu season, which may have started earlier than usual, according to CDC.
The agency on August 4 announced a small uptick in summer influenza reports, including a dozen confirmed influenza H3N2 infections in Iowa and additional reports in 11 other states.
According to CDC, the H3N2 strain responsible for cases of early illness appears to match the H3N2 component in this season`s trivalent influenza vaccines. But the virus is genetically distinct from the H3N2 strain in last season`s trivalent vaccines, so anyone vaccinated last season is not expected to have strong immunity to the new strain.
GlaxoSmithKline, MedImmune, Merck, Novartis, and Sanofi Pasteur reported this summer that they expect to supply a combined total of at least 162 million doses of influenza vaccine for the U.S. market this season.
"Perhaps the biggest challenge for this year will be anticipating what the public demand for influenza vaccine is going to be," said Tom Hall, director of pharmacy at Missouri Baptist Medical Center, which is part of the BJC health system. "Last year, there was a lot more demand on the part of the general population for influenza vaccine because of the novel H1N1."
Hall said it is simple to determine how much influenza vaccine to purchase for staff, because the BJC health system has a mandatory influenza vaccination policy for employees. The policy exempts employees with a contraindication to vaccination and allows religious objections. More than 97% of employees were vaccinated during the past two flu seasons, according to BJC.
Hall said that when the mandatory vaccination policy was implemented, managers were asked to encourage their staff to stay home if they had flu symptoms.
"We want them to stay home until their symptoms have resolved for at least 24 hours. So it`s not just the vaccination, we`re doing a lot of different things to try to prevent the nosocomial spread of influenza," Hall said.
He expects the health system to start vaccinating employees and staff in early October for the 2010–11 flu season.
Steven Kastendieck, pharmacy operations manager at Abbott Northwestern Hospital in Minneapolis, said about 60-some percent of employees in his health system get a flu vaccine each year.
"Our growth rate amongst the employee population has been small but steady from year to year," he said, acknowledging that the coverage is less than ideal. "I think there`s a lot of naiveté and miscommunication that people have allowed to become part of their permanent thinking process, that vaccines are all dangerous," Kastendiek said.
He said inpatient demand for flu vaccine is increasing because the staff is getting better at screening patients` vaccination status. But problems occur when patients are febrile or otherwise not ready to be vaccinated, and their doses are returned to the pharmacy for use the next day. Kastendiek called this process "logistically cumbersome" because the back-and-forth movement of influenza vaccine doses must be limited to minimize temperature excursion times.
"We still haven`t figured out a better way of doing that. And I think that`s going to be an ongoing challenge," he said.
Carol Rudo, associate chief of pharmacy for clinical services at the Veterans Affairs (VA) Maryland Health Care System in Baltimore, said the medical center administered trivalent influenza vaccine to about 20,500 patients last season, up from about 17,000 in 2006. She said initial staff vaccination efforts are targeted toward workers with patient care responsibilities, although VA encourages all of its employees to get vaccinated against influenza.
Rudo said the Baltimore VA Medical Center has long held a walk-up "flu lobby clinic" for patients and staff to get their annual influenza vaccination.
Last season, pharmacy staff participated in the clinic, which was formerly "a nursing initiative," Rudo said.
"They had some difficulty in trying to keep it staffed. Pharmacists were able to kind of pick up some of the slack and then extend the hours," Rudo said.
She said the health system`s clinical pharmacists administer influenza and pneumococcal vaccines in inpatient settings as well as the lobby clinic and outpatient clinics.
Rudo said the medical center was asked to order more trivalent vaccine for this season than for last season. The first shipment of influenza vaccine is expected in mid-October, and vaccination will begin immediately afterward, she said.
She said the lobby clinic will continue until demand for the vaccine wanes significantly, but vaccination will continue to be available through the health system`s clinics and pharmacies.
