H1N1 Influenza (“swine flu”) Vaccine Safety

Originally posted November 10, 2009

Some medical professionals are confused about the safety of the H1N1 influenza vaccine, commonly called the swine flu vaccine.  Based on the newness of this particular strain of the flu, some doctors believe the vaccine is untested and therefore unsafe.  Some of the patients most at risk for severe influenza complications are not receiving a vaccine that could help them.  
In short, the vaccine is no more “untested” than the seasonal flu vaccine released every year.  Counseling patients to avoid the vaccine might be as irresponsible as the parents who have “swine flu parties” to infect their children in much the same tradition as “chicken pox parties.”
While new technologies are being researched and developed, influenza vaccine production has changed very little since its discovery.  In 1931, viral growth in embryonated hens’ eggs was discovered, and in the 1940s, the US military developed the first approved inactivated vaccines for influenza, which were used in the Second World War. [1]  The current egg-based technology for producing influenza vaccine was created in the 1950s. [2] 
In the U.S. swine flu scare of 1976, President Gerald Ford was confronted with a potential swine flu pandemic.  The vaccination program was rushed, yet plagued by delays and public relations problems.  Meanwhile, maximum military containment efforts succeeded unexpectedly in confining the new strain to the single army base where it had originated.  On that base a number of soldiers fell severely ill, but only one died.  The program was canceled, after about 24% of the population had received vaccinations. An excess in deaths of twenty-five over normal annual levels as well as 400 excess hospitalizations, both from Guillain-Barré syndrome, were estimated to have occurred from the vaccination program itself, illustrating that vaccine itself is not free of risks.  The result has been cited to stoke lingering doubts about vaccination. [3]
While the substrate for all injectable influenza vaccines is the same, the inactivated virus used in the vaccine changes from season to season depending on what strain is present or anticipated in the population.   The safety and efficacy of the H1N1 vaccine is statistically the same as the trivalent seasonal influenza vaccine.  In layman’s terms, the swine flu vaccine is the same as the regular seaonal flu vaccine.  Your chances of avoiding flu-realted complications are better with the vaccine than without it.
Mindy Allport-Settle is the CEO of PharmaLogika, Inc. and is a consultant to the life sciences industry.  She has worked extensively with the manufacturing development of traditional and non-traditional vaccine platforms.[1]  Influenza Report article Vaccines by Stephen Korsman
[2]  NEJM Volume 352:1839-1842 May 5, 2005 Number 18 articlePreparing for the Next Pandemic by Michael T. Osterholm
[3]  The Sky is Falling: An Analysis of the Swine Flu Affair of 1976 by Joel Warner