Donation of 3 million treatments of oseltamivir to WHO will help early response to an emerging influenza pandemic

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>Donation of 3 million treatments of oseltamivir to WHO will help

>early response to an emerging influenza pandemic

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Donation of 3 million treatments of oseltamivir to WHO will help

early response to an emerging influenza pandemic

25 Aug 2005

 

Today, the World Health Organization (WHO) welcomes Roche's donation

of three million treatment courses of the antiviral oseltamivir to a

WHO international antiviral stockpile. WHO would use this stockpile

to respond quickly to an emerging influenza pandemic.

 

As part of its work to prepare for, detect and mitigate the impact

of an influenza pandemic, WHO is creating an international stockpile

of antiviral drugs for rapid response at the start of a pandemic. In

an agreement signed today, Roche has committed to providing three

million treatment courses (30 million capsules) of oseltamivir

(Tamiflu) to WHO, which would be dispatched to people in greatest

need at the site of an emerging influenza pandemic.

 

Oseltamivir could help to reduce illness and death, and when

combined with other measures, could potentially contain an emerging

pandemic virus or slow its national and international spread. If it

reaches the site of an outbreak quickly, an antiviral stockpile could

especially help people in poorer countries.

 

" Right now, many wealthy countries are creating their own stockpiles

of antivirals. However poor countries simply cannot afford to do

this. If a flu pandemic were to emerge in a poor country for example,

these drugs could be flown quickly to the centre of a potential

pandemic, " said Dr LEE Jong-wook, Director-General of WHO, during an

influenza news conference today in Geneva. " We urge other countries

to help us build up the international stockpile. "

 

The WHO stockpile is meant to complement other measures of

international and national preparedness, including any national

stockpiles.

 

WHO is carefully monitoring the ongoing avian influenza outbreaks in

parts of Asia, Russia and Kazakhstan. WHO warns that these and other

outbreaks could evolve into a global influenza pandemic if the avian

influenza virus changes into a form which could transmit easily

between people. The longer the current avian influenza strain (H5N1)

continues to circulate, the greater the possibility that people will

be infected with H5N1, and therefore the greater the risk that the

virus will adapt to people and trigger a pandemic.

 

Should a pandemic strain emerge, slowing its spread will be vital as

this could buy valuable time to produce vaccines against the virus

and introduce other emergency measures. Antivirals, used intensively

in an area where a pandemic is emerging, combined with other measures

such as quarantine and isolation, could help to delay spread.

 

Roche has agreed to reserve three million treatment courses (30

million capsules) for up to five years. The first one million

treatment courses (10 million capsules) will be ready early next

year, with the remaining two million (20 million capsules) ready

before mid-2006.

 

The timing and severity of a flu pandemic is uncertain, but experts

predict a pandemic will occur. Therefore WHO continues to urge

countries to develop preparedness plans. Planning must include

international cooperation between wealthy and poor countries to

reduce the opportunity for national and international spread, and to

reduce the death, illness and social disruption which have been a

feature of all previous influenza pandemics.

 

Overview of the present situation

 

Outbreaks of highly pathogenic H5N1 avian influenza in poultry are

now known to have begun in parts of South-east Asia in mid-2003.

These outbreaks have been historically unprecedented in their

geographical size and the number of birds affected. So far, around

150 million birds have died during the outbreaks or been destroyed as

part of the containment effort.

 

While some of the initially affected countries have successfully

contained the disease in poultry, the virus is now considered

entrenched in many parts of Viet Nam and Indonesia and in some parts

of Cambodia, China, Thailand, and possibly also Laos.

 

To date, human cases have been confirmed in four countries: Viet

Nam, Thailand, Cambodia, and Indonesia.

 

During early August 2005, highly pathogenic H5N1 avian influenza was

confirmed in poultry in parts of Siberia, Russia and in adjacent

parts of Kazakhstan. Both countries have reported deaths of migratory

birds in the vicinity of poultry outbreaks. These events mark the

first detection of highly pathogenic H5N1 avian influenza in the two

countries. Last week, avian influenza of the H5 subtype was confirmed

in dead migratory birds in Mongolia. No human cases have been

reported in conjunction with any of these newer outbreaks.

 

Assessment of the pandemic threat

 

WHO considers the present risk of a pandemic great, but

unpredictable in terms of its timing and severity. All conditions for

the start of a pandemic have been met save one: changes in the virus

that would make it contagious among humans, thus allowing easy and

sustainable human-to-human transmission. The likelihood that this

will happen is a matter of opportunity and probability.

 

The expanding geographical range of the virus increases

opportunities for human cases to occur and these, in turn, increase

opportunities for the virus to improve its transmissibility. The fact

that the virus is now endemic in poultry populations in several

countries increases the probability that this will occur.

 

In response to the pandemic threat, WHO has recommended a series of

strategic actions to be undertaken by affected and at-risk countries,

by WHO, and by the international community. These actions are

phase-wise according to escalating levels of risk, and pertain to the

present pre-pandemic situation, the first emergence of a contagious

virus, and the declaration of a pandemic and subsequent international

spread. In the present situation, recommended strategic actions aim

to reduce opportunities for human infection (by controlling the

outbreaks in poultry and avoiding contact between humans and infected

birds), and to strengthen the early warning system.

 

Experts anticipate that a virus with improved transmissibility will

announce itself in the form of clusters of human cases, closely

related in time and space. Surveillance and reporting systems in all

countries experiencing outbreaks in birds need to be strong enough to

detect such clusters of human cases.

 

Internal stockpile of antiviral drugs

 

If the first signs of improved transmissibility are picked up

quickly, there is a chance that rapid intervention, involving mass

prophylactic administration of antiviral drugs, might contain the

pandemic at its source or at least delay international spread,

gaining time to intensify preparedness. An international stockpile of

antiviral drugs is needed for this purpose. The prospect of halting a

pandemic at its source or delaying its international spread is

attractive, but untested, as no attempt has ever been made to alter

the natural course of a pandemic. Successful intervention requires

that at least 5 conditions be met:

 

-- The first viruses that show an ability to sustain transmission

among humans will not yet be highly contagious.

 

-- The emergence of such viruses will be limited to a small geographical area.

 

-- The first clusters of human cases caused by the virus will be

rapidly detected and reported.

 

-- Antiviral drugs will be rapidly mobilized from the stockpile,

made available to the affected population, and administered to

sufficiently large numbers of people.

 

-- Movement of people in and out of the area will be effectively restricted.

 

Given the unpredictable nature of influenza viruses, it is

impossible to know in advance if the first two conditions will be

borne out in reality when a pandemic virus emerges. The remaining

conditions require excellent surveillance and logistics capacity in

the initially affected area, combined with an ability to enforce

movement restrictions.

 

While mass intervention with antiviral drugs has no guarantee of

success, it nonetheless needs to be undertaken as it represents one

of the few preventive options for an event with predictably severe

consequences for every country in the world. As drugs in the

stockpile can also be used for treatment purposes, having such a

stockpile provides the best guarantee that populations affected at

the start of a pandemic and thus in greatest need will have drugs

available for treatment.

 

Once the virus has become fully contagious, its spread to all parts

of the world is considered unstoppable. However, some non-medical

interventions, such as quarantine, movement restrictions, and the

banning of public gatherings, could potentially delay introduction of

the virus to new areas.

 

Vaccines, if available early enough and in sufficient quantities,

can reduce the high morbidity and mortality typically experienced

during influenza pandemics.

 

http://www.who.int

 

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