Photo Credit - CDC PHIL
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Although the elderly (> 65) are considered to be the most endangered by influenza infection, they are also the group least likely to be protected by the seasonal flu vaccine (see PLoS One: Limited Effectiveness Of Flu Vaccines In The Elderly & Flu Shots And The Elderly).
That isn’t to say the flu vaccine is worthless, or not worth bothering with – only that the amount of protection for the elderly is generally less than for other age cohorts.
In 2011, NFID - the National Foundation for Infectious Diseases - convened a group of experts to address the issues of influenza and the elderly. From that panel a 5-page brief has emerged, called: Understanding the Challenges and Opportunities in Protecting Older Adults from Influenza.
This report pointed out that although the elderly generally see less protection from the flu vaccine, older individuals may still mount a robust immune response. In populations 65 and older, the brief points out that:
- Hospitalization rates for influenza and pneumonia are lower in community-dwelling adults who received the seasonal influenza vaccine.
- Immunization is associated with reduced hospitalization of older patients for cardiac, respiratory, and cerebrovascular diseases.
While the goal of vaccinating the younger population is to prevent infection, the authors point out that:
- . . . the goal in older adults is to prevent severe illness, including exacerbation of underlying conditions, hospitalization, and mortality.
Similarly, over the past couple of years, we’ve seen studies suggesting the flu vaccine may reduce the risk of heart attack and stroke (see JAMA: Flu Vaccine and Cardiovascular Outcomes & Study: Flu Vaccine May Reduce Heart Attack). .
Yesterday, the CDC announced the results of a study published in Clinical Infectious Diseases. First a link to the study, then some excerpts from the CDC statement.
Alicia M. Fry1, Inkyu K. Kim1,2, Carrie Reed1, Mark Thompson1, Sandra S. Chaves1, Lyn Finelli1, and Joseph Bresee1
Abstract
We compared influenza vaccine-prevented hospitalizations in adults aged>65 years for a range of hypothetical effectiveness estimates. During 2012-13, a vaccine with 10% effectiveness (66% coverage)would have averted ∼13,000 hospitalizations and a vaccine with 40% effectiveness would have averted ∼60,000 hospitalizations.Annual vaccination is merited in this vulnerable population.
This from the http://www.cdc.gov/flu website.
CDC Study Concludes Flu Vaccination Prevents Hospitalizations in Older People
Hospitalizations averted even when vaccine effectiveness is lower
May 9, 2014 – A new CDC study shows that flu vaccines prevent flu-associated hospitalizations in people 65 years and older, even during seasons when vaccine effectiveness is low. The study reinforces CDC’s existing recommendation for annual vaccination of adults 65 years and older who are at high risk for serious flu-related complications and often most impacted by serious flu disease each year resulting in hospitalization or death.
The study, published in Clinical Infectious Diseases online on May 6, 2014, used statistical modeling to estimate flu-vaccine-prevented hospitalizations in adults aged 65 years and older for estimates of vaccine effectiveness against medically attended influenza illness ranging from 10% to 70%. Researchers used CDC flu surveillance data collected during the 2011-12 and 2012-13 seasons. The 2011-12 season was considered to be a mild flu season, whereas the 2012-13 season was characterized as moderate to severe. Using data from these two seasons, researchers were able to determine the varying impact that flu vaccination had in terms of hospitalizations prevented.
Findings showed that during the more severe 2012-13 flu season, a flu vaccine with 10% effectiveness (and 66% coverage) would avert about 13,000 hospitalizations, whereas a vaccine with 40% effectiveness would avert about 60,000 hospitalizations. In contrast, during the more mild 2011-12 season, a flu vaccine with the same two effectiveness estimates would avert about 2,000 and 11,000 hospitalizations, respectively.
Despite disappointing VE (Vaccine Effectiveness) numbers (see CIDRAP: A Comprehensive Flu Vaccine Effectiveness Meta-Analysis) - particularly among the elderly (see BMC Infectious Diseases: Waning Flu Vaccine Protection In the Elderly) - we continue to see evidence of benefit from the shot, even if full protection isn’t conveyed to the recipient.
As addressed back in 2012 by CIDRAP: The Need For `Game Changing’ Flu Vaccines, there is obviously a great need for better, more effective, and faster to the market flu vaccines. But even with their current limitations - I certainly get one each year - and I urge others to do the same.
Not because it is guaranteed protection . . . .
But because – like wearing a seatbelt during a motor vehicle crash – it substantially improves your odds of a good outcome.
