AVIAN INFLUENZA – MIGHT NATURAL PRODUCTS HAVE A ROLE TO PLAY IN A PANDEMIC?
Dr Robert Verkerk and Julia Pendower, of the Alliance for Natural Health, review the current threat posed by avian flu and discuss the potential of natural products to minimize and alleviate the symptoms of avian flu during the critical time when no vaccine will be available and for the 75 percent of the population who may be unable to get it even when one is.
"The 1918 has gone: a year momentous as the termination of the most cruel war in the annals of the human race; a year which marked, the end at least for a time, of man’s destruction of man; unfortunately a year in which developed a most fatal infectious disease causing the death of hundreds of thousands of human beings. Medical science for four and one-half years devoted itself to putting men on the firing line and keeping them there. Now it must turn with its whole might to combating the greatest enemy of all – infectious disease."
The timeline for the spread of the deadly H5N1 virus, as published by the World Health Organization (WHO)1, makes one thing very clear: the virus has, since being identified in 1997, become endemic among wild bird populations in many parts of the world and has subsequently infected a wide range of domestic and wild animals including poultry, pigs, horses, cats and civets.
While anthropocentricity has caused many to ignore the implications of this, humans have increasingly become susceptible to the rapidly mutating virus. The first cases of human infection were detected in 2003, in humans exposed to sick birds. The number of WHO-confirmed human cases approximately doubled between 2004 and 2005 (46 and 95 respectively), whereas the number of cases in the first five weeks of 2006 has more than doubled when compared with the average over the same time period in 2005. The proportion of infected individuals dying has hovered, disconcertingly, at a little over 50% since 2003.(2)
As yet, the crucial mutations or genetic re-assortment required to create sustained human-to-human transmission have not occurred – and this is the final prerequisite for the initiation of a pandemic. Experts estimate that the pandemic might lead to the death of some 70 million people worldwide.
The cause of mortality in H5N1 avian influenza infection appears to be primarily from what is termed a ‘cytokine storm’ in the immune system, which leads to viral pneumonia. This is a condition in which the immune system massively over-responds and becomes imbalanced, resulting in an overproduction of IL-6, IL-10, RANTES and interferon-beta cytokines.
The big questions in the minds of many people are: will the virus continue to spread slowly into human populations, will it initiate a pandemic and, if so, will it give rise to great loss of life and distress and precipitate social disorder and economic recession on a scale unprecedented in recent history? Some feel that the risks are over-exaggerated and, like SARS and the 1957 and 1968 influenza pandemics, should an H5N1 pandemic arise in the near future, it will be comparatively mild.
What does the World Health Organization say?
The WHO, which has been monitoring the H5N1 virus for the last eight years, is certainly not understating the potential risks.
On its website, the WHO provides summary information on ‘10 things you need to know about pandemic influenza’. (3) These are:
- Pandemic influenza is different from avian influenza
- Influenza pandemics are recurring events
- The world may be on the brink of another pandemic
- All countries will be affected
- Widespread illness will occur
- Medical supplies will be inadequate
- Large numbers of deaths will occur
- Economic and social disruption will be great
- Every country must be prepared
- WHO will alert the world when the pandemic threat increases.
The WHO and other experts variously describe a pandemic as ‘inevitable’, ‘possibly imminent’ and ‘one of the greatest threats to humanity’.
No-one, not even the WHO and the experts within its Global Influenza Programme are in a position to know just when the necessary adaptation of the H5N1 virus to humans will occur, but there is scientific consensus that this is the sole remaining pre-requisite to initiate a devastating pandemic. Since Influenza A viruses are so labile, it seems that probability might suggest these genetic changes will occur sooner rather than later. In essence, we are talking about a high risk of a pandemic this year or at least in the next three or so years. In terms of historical precedent, it seems a pandemic is overdue.
Strategies for mitigation
Pandemic preparedness plans are placing great weight on the need to reduce transmission of the virus, as well as the use of vaccines and anti-viral drugs. While any prevention strategy designed to reduce transmission as far as possible is admirable and should be supported in every way, there are widespread concerns with the use of vaccines and anti-viral drugs. These are the key weapons being offered by the pharmaceutical industry – and demand for these products in a pandemic would be so great that supply would likely be limited, costs would be very high (prohibitive for many) and efficacy might be low.
It is widely accepted that vaccines will be broadly unavailable during a pandemic. Not only does the pandemic strain have to emerge before an effective vaccine can be developed, it is also estimated that it will take approximately six months before such a vaccine can be developed. A November, 2004, WHO consultation reached the stark conclusion that, on present trends, the majority of developing countries would have no access to a vaccine during the first wave of a pandemic and possibly throughout its duration.(4)
Once a vaccine is available it will only be effective against a single strain of H5N1. The experience of 1918 showed at least three distinct waves of infection: each of these was probably caused by different subtypes of the H1N1 pandemic virus and infection in an early wave did not appear to confer immunity to a re-infection by a later variant. It is highly probable that H5N1 will follow a similar path.
Even at maximum manufacturing capacity, a combination of problems associated with production (requirement to grow vaccine on chicken eggs), the possibility of requiring two vaccinations to acquire immunity, plus severe limitations in production capacity are likely to mean that vaccines developed against a specific subtype will only be available for a small proportion of the population and are likely to arrive too late to be of benefit.
Some 23 governments have ordered Tamiflu for national stockpiles as the primary drug intervention and the UK will have sufficient supplies to cover 25 percent of the population with a single course of Tamiflu at label dosage by August, 2006.
A study led by Dr Thomas Jefferson of the Rome-based Cochrane Vaccines Field, published on 19th January, 2006, in The Lancet, identified that 16 percent of cases of human H5N1 avian influenza infection already had a viral type with Tamiflu resistance.5 The same authors also showed that both Tamiflu and Relenza would not prevent infection, but may reduce the severity of symptoms. In the opinion of many experts, widespread use of either drug in a pandemic is likely to lead relatively rapidly to viral drug resistance.
Tamiflu has been demonstrated to be of benefit if used prophylactically or within 18 hours of infection. However, it has also been demonstrated that a course at double the label dosage and for double the duration (ie. 10 days) is required for the drug to be effective. This means that, used in this manner, the UK stockpile would only cover a little over 6 percent of the population, excluding any provision for prophylactic use in key workers and their families.
Given that both the UK Pandemic Plan, the WHO plan and others all estimate an infection rate of 25 percent of populations at any single point of time, it is clear that there will be insufficient drug supplies to cover needs, always assuming that this drug remains beneficial.
The potential use of natural products
In view of a very likely widespread shortage of prescription medications in the event of a pandemic, it is to be expected that a significant proportion of individuals will use natural products and herbal medicinal approaches to help prevent or treat the disease.
Interestingly, natural product trade associations have already begun to take a stand on this issue and are upholding that companies selling natural products should not associate them with avian influenza as this is a serious disease requiring licensed medicinal products for treatment.
This is indicative of the food-medicine conundrum that has existed in Europe, the USA and many other parts of the world for more than 40 years: poor diet has been amply demonstrated to be associated with a wide range of chronic diseases and compromised immunity, yet it remains illegal to make any claims as to the role of food products in reducing the risk of disease. This status quo actually creates a situation in which foods or food products cannot be actively promoted for health promotion or disease prevention. We are left with a situation in which people take medicinal products only when they are sick, while the law restricts information which would encourage use of health-promoting food products in disease prevention.
Irrespective of the law, during a pandemic it is highly likely that large sectors of the population would anyway utilize food supplements and herbal products to help protect themselves. However, inappropriate use of some natural products, such as Echinacea, which creates a generalized boost of the immune response, could actually further stimulate cytokine responses that would exacerbate a potentially lethal ‘cytokine storm’.
However, other appropriate interventions with natural products could be of benefit in immune system modulation. It is therefore imperative that the public are properly informed and educated about which approaches they can take to strengthen and effectively modulate their immune system.
Based on the available evidence, it is entirely possible that natural products, used appropriately, might be able to offer more in the way of prevention and treatment than pharmaceutical drugs.
Given that recent developments in Turkey have seen the H5N1 acquire two key mutations that bring the probability of a pandemic very much closer, the need to address these issues and determine appropriate and effective approaches that utilize natural and nutritional approaches which could be used in prevention is pressing and urgent. The appearance of the PB2 667K mutation has provided the virus with the ability to replicate efficiently at human body temperatures and the acquisition by the virus of the 223N mutation now means that a strain of the virus exists that prefers human to avian epithelia for initial infection. According to a press announcement by Dr Cheng of the WHO on the 19th January, 2006, a further mutation has also been observed but its significance is presently uncertain. All of these factors indicate that the world could be at the cusp of a pandemic.
The Alliance for Natural Health has established an Avian Flu Expert Committee to deal specifically with the issues of natural product usage during a pandemic. Critical to its work is the compilation of a report containing a detailed review of the peer-reviewed research on natural products that might be beneficial or detrimental in the event of an avian influenza pandemic. The report will be submitted to national and international health authorities, as well as being made available to the public.
For further information, please contact: Alliance for Natural Health, +44 (0)1252 371 275; firstname.lastname@example.org; www.alliance-natural-health.org .
1. WHO website: http://www.who.int/csr/disease/influenza/pandemic10things/en/.
2. World Health Organization. Responding to the avian influenza pandemic threat: Recommended strategic actions, 2005 (http://www.who.int/csr/resources/publications/influenza/WHO_CDS_CSR_GIP_05_8-EN.pdf).
3. WHO website: http://www.who.int/csr/disease/influenza/pandemic10things/en/.
4. World Health Organization. Responding to the avian influenza pandemic threat: Recommended strategic actions, 2005 (http://www.who.int/csr/resources/publications/influenza/WHO_CDS_CSR_GIP_05_8-EN.pdf).
5. Jefferson T, Demicheli V, Rivetti D, Jones M, Di Pietrantonj C, Rivetti A. Antivirals for influenza in healthy adults: systematic review. Lancet Early Online Publication, 19 January, 2006.