# 7222
The road to creating, producing, and deploying an emergency pandemic vaccine can be long and fraught with many unexpected twists and turns. Under the best of circumstances it takes several months before the first commercial batches can roll off the production line.
So it pays to start the development process as early as possible, even before you know for certain a vaccine will be needed.
We’ve seen the precautionary selection of CVVs (Candidate Vaccine Viruses) before, with the H5N1, H3N2v and H9N2 viruses (see H3N2v Vaccine Trials & Bangladesh To Share H9N2 Bird Flu Virus).
While no nation, health organization, or pharmaceutical company has decided to proceed with the mass production of an H7N9 vaccine, the preliminary – and prudent – steps of identifying, growing, and testing potential vaccine candidate strains is underway.
Yesterday, the World Health Organization released a document (02 May 2013 Candidate vaccine viruses of A(H7N9) pdf, 103kb) outlining the process.
A few excerpts, then I’ll return with a little more.
2 May 2013
Influenza vaccination is the most important intervention in reducing the impact of influenza, and a key component of the WHO response and preparedness efforts for influenza of pandemic potential, including avian influenza A(H5N1), A(H9N2) and A(H7N9).
Development of candidate vaccine viruses
The first step in the long cycle of vaccine development and production is vaccine virus selection and the development of high-growth reassortants (candidate vaccine viruses (CVVs)). This is a well-established process and has been in place since the 1970s. It was further strengthened during the response to A(H5N1) and pandemic A(H1N1) 2009, mainly through the WHO Global Influenza Surveillance and Response System (GISRS) which currently comprises 150 laboratories in 111 countries.
Since the detection of avian influenza A(H7N9) virus in China, GISRS has been on alert. Through the excellent work undertaken by the WHO Collaborating Centre (WHO CC) in Beijing, viruses have been isolated and shipped to other WHO CCs and Essential Regulatory Laboratories (ERLs) of GISRS for joint virus characterization, development of diagnostic tests, risk assessment and candidate vaccine virus development for pandemic preparedness purposes.
Using the two available technologies, classical reassortment and reverse genetics, the WHO CCs and ERLs are developing high-growth reassortants that are suitable for vaccine development and production. The status of development of CVVs will be updated routinely by WHO for influenza vaccine manufacturers, national/regional regulatory agencies and other interested parties.
While emergency vaccines certainly have value – particularly for the second or third wave of a pandemic - it would be highly unlikely that one could be produced, and deployed in sufficient quantity, to have much effect on the initial wave of any pandemic.
Last month, in Branswell On The Challenges Of Producing An H7N9 Vaccine, we looked at some of the problems inherent in developing an emergency avian flu vaccine.
And a month ago, in H7N9 Vaccine Realities, we looked at the gap between predicted vaccine supplies during the 2009 pandemic, and actual vaccine deliveries.
At the time I wrote:
In a world of 7 billion, the reality is that our ability to manufacture and (just as importantly) distribute a pandemic vaccine in a short amount of time remains severely limited.
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It is likely that relatively few people could expect to see any novel pandemic vaccine in less than six months from the time production started.
And most of the world would probably still be waiting after a year.
The truth is, our first line of defense in any pandemic is not a shot or a pill, it is a range of steps collectively called NPIs, or Non Pharmaceutical Interventions.
The CDC’s Nonpharmaceutical Interventions (NPIs) webpage defines NPIs as:
Nonpharmaceutical interventions (NPIs) are actions, apart from getting vaccinated and taking medicine, that people and communities can take to help slow the spread of illnesses like influenza (flu). NPIs are also known as community mitigation strategies.
NPIs are geared to the virulence and spread of the virus, and may range from simple advice to `wash your hands and cover your coughs’ to mandatory school and business closings.
Should the H7N9 virus, novel coronavirus, or any other novel virus threaten, we’ll be talking a lot about NPIs, and their efficacy, impact, and practicality in the blog.
Admittedly, H7N9 remains a distant threat and may never spark a pandemic.
But H7N9 isn’t the only pathogenic contender capable of sparking the next global health crisis.
H5N1 circulates in Asia and the Middle East, several varieties of swine variant H1 and H3 viruses have jumped to humans in recent years, and the novel coronavirus emerging on the Arabian peninsula has many scientists visibly concerned.
All of which makes now a very good time for governments, agencies, businesses and organizations to dust off, update, and test their pandemic preparedness plans.
Because history has taught us that pandemics happen.
We just don’t know when, and from where, the next one will come.
