comparison of full-dose flu vaccine to half-dose flu vaccine

Conditions: Influenza

Summary: this study compared full-dose flu vaccine to half-dose flu-vaccine during the 2004-2005 flu season.

this was a phase ii prospective, single-blind to dose, randomized study that compared the immunogenicity of subjects receiving half-dose fluzone® compared to full-dose fluzone®, 2004-2005 formulation. 1440 healthy subjects, ages 18-64 years old and not currently indicated for influenza vaccination under the interim acip guidelines, were divided into 8 strata based on age, gender, and previous exposure to influenza vaccine, and randomized to receive either half-dose (0.25ml) fluzone® or full-dose (0.5ml) fluzone® by intramuscular injection into the deltoid muscle.

Eligibility criteria:
inclusion criteria: * able to understand and comply with all study procedures including availability for all study visits and follow up surveys within 6 months following study enrollment. * deers eligible beneficiaries eligible for influenza vaccination and able to give informed consent. * age 18-49 * patients presenting to travel clinic with no exclusion criteria; * household contacts and out-of-home caretakers of infants from 6-23 months of age; * hospital and/or employees providing service to the public who are not eligible for the post-october 5th recommendations for priority immunization; * dod employees eligible for influenza vaccination prior to october 5th but excluded in the post october 5th guidelines; * people living in dormitories or under other crowded conditions, to prevent outbreaks; * ages 50-64 years of age who are not eligible for the post-october 5th recommendations for priority immunization and with no standard of care contraindications to vaccination. * eligible in the department of defense for influenza vaccination exclusion criteria: * all children aged \< 18 years (includes children aged 6 months-18 years on chronic aspirin therapy); * adults aged \>65 years; * persons aged 2-64 years with underlying chronic medical conditions: * includes persons with chronic cardiac or pulmonary disease, diabetes mellitus, hemoglobinopathy, or immunosuppressive illness; * any acute or chronic condition that, in the opinion of the investigator, would render vaccination unsafe or interfere with the evaluation of response. * use of experimental vaccines or medications within 30 days of study entry; * receipt of parenteral immunoglobulin within 60 days of study entry; * all women who will be pregnant during the influenza season; * residents of nursing homes and long-term care facilities; * health-care workers involved in direct patient care and included in dod priority 1; and; * military recruits; * out-of-home caregivers and household contacts of children aged \<6 months. * anyone with clinical contraindications for receiving the inactivated influenza vaccine such as a history of severe allergic reaction to prior influenza vaccinations, severe allergy to egg and/or egg proteins and gelatin. * dod priority 1: deployed or deploying (with orders) service members and others designated as critical to national defense. * dod priority 2: medically high risk in accordance with acip guidelines (includes health-care workers with direct patient contact) * any acute or chronic condition that, in the opinion of the investigator or her provider designee would render vaccination unsafe or interfere with the evaluation of the response.

Keywords: influenza