On 2014 Feb 12, David Keller commented:

None

On 2014 Feb 12, David Keller commented:

The “Special Article” on Influenza Vaccines by Peter Doshi, PhD. (1) casts doubts on the benefits of influenza vaccination in a way which could dangerously mislead clinicians. He states that “influenza vaccines target a disease that is, for most people, self-limiting. While unpleasant, today, tragedies are rare”. This statement ignores the role the vaccine has played in preventing tragedies such as the 1918 flu pandemic, in which influenza was seen to be a highly contagious infection capable of quickly killing untold millions of humans, including the young and healthy. Doshi further states that between 33 and 100 adults would need to be vaccinated to prevent one case of influenza. This statistic is misleading because it pertains to the U.S. population, in which tens of millions get annual flu vaccinations, providing individuals with a broad-spectrum of antibodies to influenza, and partial herd immunity at a population level. The number needed to treat to prevent one case of influenza would undoubtedly be much lower if this huge segment of the population were not immunized. To achieve the full benefits of herd immunity, at least 80% of healthy Americans must be immunized (2), which is a worthy goal. Doshi cites retrospective cohort studies showing a 48% reduction in mortality among the elderly who are vaccinated, but decries the lack of evidence from placebo-controlled trials. However, given the evidence we do have, it would seem unethical to administer placebo instead of influenza vaccine to persons over age 75, for lack of equipoise (the same reason a randomized controlled trial of smoking has never been conducted). Doshi objects that the increase in influenza vaccination rates has not been accompanied by a decrease in total winter mortality. However, the relevant statistic to examine would be age-adjusted annual mortality. Everyone dies sooner or later, but I would rather die at age 85 than at age 75, regardless of the season, even if it means I have to get a flu shot annually. The problem among the elderly of inadequate antibody titer increase after influenza vaccine has been pointed out before, and is being addressed by such measures as increasing the dose of vaccine or changing the route of administration (3); it is not a reason to abandon the benefits of immunization in this population.

1) Doshi P. Influenza Vaccines: Time for a Rethink. JAMA Intern Med.2013;173(11):1014-1016. doi:10.1001/jamainternmed.2013.490.

2) Plans-Rubió P. The vaccination coverage required to establish herd immunity against influenza viruses. Prev Med. 2012 Jul;55(1):72-7. doi: 10.1016/j.ypmed.2012.02.015. Epub 2012 Mar 4.3.

3) DiazGranados CA, Dunning AJ, Jordanov E, Landolfi V, Denis M, Talbot HK. High-dose trivalent influenza vaccine compared to standard dose vaccine in elderly adults: safety, immunogenicity and relative efficacy during the 2009-2010 season. Vaccine. 2013 Jan 30;31(6):861-6. doi: 10.1016/j.vaccine.2012.12.013.

On 2014 Feb 12, David Keller commented:

The “Special Article” on Influenza Vaccines by Peter Doshi, PhD. (1) casts doubts on the benefits of influenza vaccination in a way which could dangerously mislead clinicians. He states that “influenza vaccines target a disease that is, for most people, self-limiting. While unpleasant, today, tragedies are rare”. This statement ignores the role the vaccine has played in preventing tragedies such as the 1918 flu pandemic, in which influenza was seen to be a highly contagious infection capable of quickly killing untold millions of humans, including the young and healthy. Doshi further states that between 33 and 100 adults would need to be vaccinated to prevent one case of influenza. This statistic is misleading because it pertains to the U.S. population, in which tens of millions get annual flu vaccinations, providing individuals with a broad-spectrum of antibodies to influenza, and partial herd immunity at a population level. The number needed to treat to prevent one case of influenza would undoubtedly be much lower if this huge segment of the population were not immunized. To achieve the full benefits of herd immunity, at least 80% of healthy Americans must be immunized (2), which is a worthy goal. Doshi cites retrospective cohort studies showing a 48% reduction in mortality among the elderly who are vaccinated, but decries the lack of evidence from placebo-controlled trials. However, given the evidence we do have, it would seem unethical to administer placebo instead of influenza vaccine to persons over age 75, for lack of equipoise (the same reason a randomized controlled trial of smoking has never been conducted). Doshi objects that the increase in influenza vaccination rates has not been accompanied by a decrease in total winter mortality. However, the relevant statistic to examine would be age-adjusted annual mortality. Everyone dies sooner or later, but I would rather die at age 85 than at age 75, regardless of the season, even if it means I have to get a flu shot annually. The problem among the elderly of inadequate antibody titer increase after influenza vaccine has been pointed out before, and is being addressed by such measures as increasing the dose of vaccine or changing the route of administration (3); it is not a reason to abandon the benefits of immunization in this population.

1) Doshi P. Influenza Vaccines: Time for a Rethink. JAMA Intern Med.2013;173(11):1014-1016. doi:10.1001/jamainternmed.2013.490.

2) Plans-Rubió P. The vaccination coverage required to establish herd immunity against influenza viruses. Prev Med. 2012 Jul;55(1):72-7. doi: 10.1016/j.ypmed.2012.02.015. Epub 2012 Mar 4.3.

3) DiazGranados CA, Dunning AJ, Jordanov E, Landolfi V, Denis M, Talbot HK. High-dose trivalent influenza vaccine compared to standard dose vaccine in elderly adults: safety, immunogenicity and relative efficacy during the 2009-2010 season. Vaccine. 2013 Jan 30;31(6):861-6. doi: 10.1016/j.vaccine.2012.12.013.