WHO announces level 6 influenza pandemic
11 June 2009
This afternoon the World Health Organisation announced a move from level 5 to level 6 on the scale of pandemic alert in response to the spread of Influenza A (H1N1).
Level 6 indicates that a global pandemic of the flu virus is underway, which means that the infection is spreading in communities in two or more regions of the world. It does not mean that the flu infection has become more severe.
Scientists at the WHO World Influenza Centre at the MRC National Institute for Medical Research in London are collaborating with other WHO centres to learn more about the Influenza A (H1N1) virus.
The following news articles and Q&A provide information about the MRC’s involvement in tackling the current pandemic.
- Pandemic potential of influenza A (H1N1) justifies warnings - 11 May 2009
- Influenza A (H1N1) - Q&A - updated 10 June 2009
- MRC involvement in influenza research - 11 May 2009
- NIMR scientist discuss swine-like human influenza A (H1N1) - 1 May 2009
- Influenza A (H1N1) virus samples on their way to MRC flu centre - 28 April 2009
- Leading MRC scientists join in global fight against influenza A (H1N1) - 27 April 2009
What is the National Institute for Medical Research’s role?
The MRC’s National Institute for Medical Research (NIMR) in Mill Hill, north London, houses the World Influenza Centre, one of five World Health Organization (WHO) Collaborating Centres for Reference and Research on Influenza. The Collaborating Centres on Influenza, together with many WHO National Influenza Centres around the world, comprise a global network coordinated by the WHO to monitor the progress of the epidemic and analyse virus samples from patients in countries around the world including the UK. Scientists at NIMR are also working closely with colleagues in the UK, notably at the Health Protection Agency to understand the nature of the epidemic, and at the National Institute for Biological Standards and Control in developing a vaccine.
What is NIMR doing with samples?
Scientists at NIMR grow viruses from the samples in a Containment Level 3 laboratory (see question ‘How is the virus being contained at NIMR?’). These viruses are characterised to identify changes in the genetic make-up of the viruses isolated in different parts of the world. They are used to prepare antisera to study the antigenic relationships among the viruses and to monitor antigenic drift – changes in the virus that could have an impact on the suitability of different vaccines. This work on the structure and evolution of the virus thus feeds into the development of vaccines. The viruses are also examined for their susceptibility to antiviral drugs to monitor their likely effectiveness. Information on the viruses is also used to prepare reagents to assist other laboratories in detecting and diagnosing virus infection.
How does the WHO centre fit in with NIMR?
The WHO Collaborating Centre for Reference and Research on Influenza at NIMR has been part of the WHO Global Influenza Surveillance Network since it was established 50 years ago. With the other four Collaborating Centres in Atlanta, Memphis, Melbourne and Tokyo, the team is responsible for monitoring changes in the influenza type A and B viruses which cause recurrent annual epidemics. It also identifies human infection by other novel influenza A subtypes, such as A (H1N1), that may be spreading within the human population towards pandemic levels, and H5N1 viruses that still pose a pandemic threat - though H5N1 infection is largely limited to direct bird to human transmission. The centre also monitors antiviral resistance among the 2000 influenza virus isolates and clinical specimens that are received each year from more than 40 countries worldwide.
What is the process for developing a vaccine?
A vaccine for the influenza A (H1N1) virus will be produced by growing the vaccine virus in either eggs or cells. One of the initial influenza A (H1N1) viruses, identified by the WHO Collaborating Centre for Research and Reference on Influenza in Atlanta, has been recommended by the WHO for development of a vaccine. The virus strain has now been received by the other WHO Collaborating Centres, including NIMR, as well as other laboratories for preparation of candidate vaccine viruses. Once developed, these strains will be distributed to vaccine manufacturers.
How quickly will vaccines be available?
The first doses of a vaccine could be available in five to six months from initial identification of the candidate vaccine virus. Regulatory approval of the vaccine will be conducted in parallel with manufacturing. Regulatory authorities have put expedited processes into place to speed up approval timelines without compromising the quality or safety of the vaccine.
How is the virus being contained at NIMR?
Work with biological agents is legislated to ensure health and safety and control of hazardous substances. Organisms are classified from Hazard Group 1 to
Hazard Group 4 as follows:
- Hazard Group 1:Unlikely to cause human disease
- Hazard Group 2:Can cause human disease and may be hazardous to employees
- Hazard Group 3: Can cause severe human disease and may be a serious hazard to employees
- Hazard Group 4: Causes severe human disease and is a serious hazard to employees
Seasonal influenza viruses are usually classified as Hazard Group 2. However if the virus becomes potentially pandemic and there is a risk of spread to the community, the hazard level is raised to Hazard Group 3 or 4. Work on the virus at NIMR is being carried out in a Containment level 3 laboratory.
Air is controlled and filtered within the laboratory. It has restricted access, safe storage for biological agents and its own equipment. The lab is sealable to allow disinfection and decontamination if necessary. Processes are in place for safe transport, collection, storage and disposal of biological agents and contaminated waste. Good occupational hygiene measures are also in place to reduce the risk of contamination. These measures are aimed at protecting both the workers and the general public.
Are antivirals effective against influenza A (H1N1) and how do they work?
Two groups of antiviral medicines are effective against influenza viruses. The newly developed sialidase inhibitors act by suppressing sialidase, a viral enzyme that plays a key role in the influenza life cycle. An older group of drugs inhibits the activity of the M2-ion channel protein of the virus, preventing the virus from infecting target cells in the host.
The new virus, influenza A (H1N1) is sensitive to both of the sialidase inhibitors Oseltamivir and Zanamivir (Tamiflu and Relenza). The UK has built up a stockpile of Tamiflu and Relenza to provide cover for 33 million people, with steps being taken to increase this to provide cover for 50 million people. These antivirals have the greatest benefit when given within two days of the onset of symptoms.
Do face masks offer protection against flu?
The Health Protection Agency is not recommending the wearing of face masks for the general public. Available scientific evidence does not suggest that this is an effective preventative measure and there are a number of practical issues to consider:
- if masks are not worn properly they may not provide any protection
- they may discourage people from carrying out good hand hygiene practices
- failure to dispose of a mask properly might pose a risk to other people and increase the risk of self-contamination and reusing a mask will render it ineffective.
For more details visit: www.hpa.org.uk
If the virus changes into something much more transmissible in 6 months time, will the vaccines being developed now still be effective?
It is too early to predict how the virus might change as it continues to circulate in the population or how similar a mutated virus might be to the current virus. Careful surveillance for changes in the virus is ongoing. This close and constant monitoring will support a quick response should important changes in the virus be detected which may have an impact on vaccine effectiveness.
Press contact: 020 7637 6011
press.office@headoffice.mrc.ac.uk
