The evidence is in: a high-dose flu shot is more effective for seniors than the standard shot. The evidence comes from a large randomized trial presented at a meeting of the Advisory Committee on Immunization Practices (ACIP).
The improvement albeit slight, is highly welcomed, given the fact that flu shots have been SHOWN to save lives, but the immune response to the standard-dose vaccine among older folks is attenuated compared to younger recipients.
The study, conducted over two flu seasons, found Fluzone High-Dose had an increased efficacy of slightly more than 24 percent compared with the standard Fluzone shot.
The Food and Drug Administration approved the higher-dose vaccine in 2009, based on previous studies that confirmed the vaccine s higher levels of flu-fighting antibodies attained by seniors a month after vaccination. The vaccine has four times the antigen dose of the standard vaccine. But to become an accepted part of the vaccine armamentarium, it needed to be approved as well by the CDC s ACIP.
The long-awaited study could shift the current statistic that only one in five seniors has received the high-dose formulation in the past three flu seasons. Experts say that was largely due to the fact that medical groups were awaiting results of this study.
The study included more than 31,000 participants 65 and older. Participants were randomly assigned to either the high-dose formulation or the standard dose of Fluzone. During the course of the study, the researchers confirmed 277 cases of the flu among the half of the participants (15, 892) who received the high-dose formulation, a rate of 1.43 percent. There were 300 confirmed cases of the flu among those seniors (15, 911) who received the standard dose, a rate of 1.83 percent. The numbers favored Fluzone High-Dose, with a 24.2 percent increased protection rate.
There was a slightly lower on-site reaction to the shot in the high-dose group compared to the standard group, and a somewhat higher price tag.
ACSH s Dr. Elizabeth Whelan had this comment: Since it has been long known that those over 65 have a significantly diminished immune response to the standard-dose flu vaccine, this clearly represents a step forward in protecting seniors from a preventable and potentially lethal infection. Since influenza kills thousands of older Americans each winter, many lives will be saved if seniors AND their doctors are made aware of this new vaccine dosage.
