24 July 2009

24 July 2009=

WHO Upda= tes Epidemiology and Vaccine Issues for Pandemic Flu (H1N1) 2009

Today the World Health Organization (WHO) posted on their pandemic influenza (H1N1) 2009 website a succinct update on the evolving epidemiology and risk factors for serious pandemic flu disease, as well as a synopsis on the development of pandemic (H1N1) 2009 virus vaccines. The full report can be read at: www.who.int/csr/disease/swineflu/notes/h1n1_situation_200= 90724/en/index.html

In terms of risk factors for serious pandemic (H1N1) 2009 influenza virus disease, WHO stated that the following “currently are considered risk factors”:

--existing cardiovascular disease

--respiratory dis= ease (including asthma)

--diabetes

--cancer

WHO also stated “there is accumulating evidence suggesting that pregnant women= are at higher risk for more severe disease”, and that “a recent rep= ort suggests that obesity may be another risk factor”.

In terms of the a= ges of persons at highest risk for infection with this novel pandemic flu virus, and for hospitalization and/or death, WHO noted that:

--The majority of cases” are still occurring in younger people, with the median age reported to be 12 to 17 years (based on data from Canada, Chile, Japan, UK<= /st1:country-region>, and the USA). WHO also said that some reports su= ggest patients who need to be hospitalized and those who die due to this new virus “may be slightly older”.

The terse synopsi= s on the pandemic vaccine situation did note two key points:

--“The development of new candidate vaccine viruses by the WHO network is continui= ng to improve yields (currently 25% to 50% of the normal yields for seasonal influenza for some manufacturers)”.

--“Manufact= urers are expected to have vaccines for use around September.”

This final commen= t on vaccines around September must refer to limited amounts of one or mo= re pandemic (H1N1) 2009 vaccines. The very first clinical trials to assess the safety and immunogenicity of multi= ple candidate vaccines in several places around the world are only beginning no= w in the second half of July.

In the USA it = is extremely unlikely, in this writer’s opinion as a former FDA vaccine reviewer, that there will be any FDA-licensed pandemic (H1N1) 2009i vaccine= by the end of September.

In the USA it = appears that the initial pandemic (H1N1) vaccine(s) are most likely going to= be grown in eggs, and will NOT include a vaccine adjuvant. In the past, the US FDA has NOT li= censed any influenza vaccines that were grown in cell culture (rather than eggs), = and also has NOT licensed any influenza vaccines that include an adjuvant.

Alum is the only FDA-licensed vaccine adjuvant. Alum has only been used with certain specific vaccines that have NOT been used w= ith any FDA-licensed influenza vaccines.

If a pandemic influenza vaccine is given with an adjuvant during the upcoming 2009-2010 f= all/winter, then it will most likely be given under the FDA’s “Emergency Use Authorization (EUA)” regulatory-legal framework.

The above-mention= ed issue of lower yields (25%-50%) of the hemagglutinin antigen from virus preparations of this pandemic (H1N1) 2009 virus, as well as the use or non-= use of effective vaccine adjuvants (e.g., perhaps oil-in-water adjuvant more so than alum) has major implications not only for developed nations such as the USA, but also for developing nations in terms of the total number of availa= ble vaccine doses worldwide at any given time.=

These subjects we= re discussed earlier this month by the US HHS/CDC, and at the WHO SAGE (Strategic Advisory Group of Experts) meeting on pandemic flu vaccine. A summary of this WHO meeting was posted July 13 at: www.who.int/csr/disease/swineflu/notes/h1n1_vaccine_2009071= 3/en/index.html

The next three mo= nths will bring a surge in information and data regarding candidate pandemic (H1= N1) 2009 vaccines from around the world. This surge will be accompanied by extensive interest globally among scientists, public health officials, clinicians, politicians, the media and the business world.

This pandemic will continue to be an historic time.

Daniel R. Lucey, MD, MPH

EROne Institutes, Department of Emergency Medicine<= /o:p>

Washingt= on Hospital Center

Department of Microbiology and Immunology

Georgeto= wn University Medical Center, Washington, DC

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