discussion title:
Natural Immunity better than Vaccine
SWINE FLU VACCINE (IF IT WORKS) MAY AVOID NATURAL IMMUNITY THAT LASTS FOR MORE THAN 50 YEARS
FDA approved vaccines against influenza A (H1N1) (1) which gives support for government plans to provide mass vaccination programs for H1N1 later this year. Such plans are irrational and based on fear mongering and not on a “common sense and self control” policy (as proposed by Spanish physicians and other health professionals) (2).
We strongly disagree with mass vaccination, which is based on several false assumptions.
The first assumption is that the H1N1 pandemic will mimic the Spanish flu of 1919. This is highly unlikely as the Spanish flu was a pandemic flu in a very poor world, with no public health systems, no tap-water and no antibiotics for complications. In support of this the Spanish flu killed mainly poor people; for example, in India it killed soldiers (in warehouses, bad food, bad hygiene conditions) but not officers (good food, British style houses, etc.).
The second assumption is that H1N1 flu is severe and deadly. There is substantial evidence that that is not the case and in fact the mortality rate from H1N1 flu is much less than seasonal flu (3,4).
The third assumption is that the vaccine will work. The immunologic response is not a guarantee that the vaccine will reduce severe infections and mortality. Demonstration of that benefit requires large RCTs (randomized controlled trials), which are lacking for both H1N1 vaccines as well as for seasonal flu vaccines.
The fourth assumption is that the H1N1 vaccine will provide similar immunity to the natural infection. Immunity to viral flu has a very interesting peculiarity that is known as the "original antigenic sin" (5). This concept means that the first flu virus we are exposed to generates the strongest immune response and that immunity lasts for over 50 years. It explains the fact that people over 50 years of age appear to have some immunity to the H1N1 virus because a similar influenza A virus, circulated globally from 1918 to 1957. Thus it appears that natural infection creates immunity for 50 years at no cost as compared to influenza vaccines, which require one (or two) shots annually to achieve a lesser degree of immunity.
We therefore recommend that most if not all H1N1 vaccine be used as part of placebo controlled RCTs to establish whether the benefits outweigh the harms. Without such an approach, in September 2010 we will again be in a position of not knowing who to vaccinate. Similar RCTs are also badly needed for seasonal flu vaccine as the long-term effects of annual flu vaccination are unknown, and there is a good chance that the harms of annual flu vaccination as compared to no vaccination outweigh the benefits.
1. Influenza A (H1N1) 2009 monovalent. http://www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm181950.htm
2. Villanueva T, Gérvas A. Spain and swine flu. CMAJ. 2009. http://www.cmaj.ca/cgi/eletters/181/6-7/E102
3. Assessment of the influenza A (H1N1) pandemic on selected countries in the southern hemisphere: Argentina, Australia, Chile, New Zealand and Uruguay. Department of Health and Human Services and other USG Departments for the White House National Security Council. 26th August 2009. http://flu.gov/professional/global/final.pdf
4. Collignon PJ. Mass vaccination against swine flu: could it cause more harm than good? http://www.bmj.com/cgi/eletters/339/sep03_2/b3471#219801
5. Couch RB, Kasel JA. Immunity to influenza in man. Ann Rev Microbiol. 1983;37:529-49.
Competing interests: None declared
