PHA-Exchange> Polio "could be eradicated" by end of decade

[Claudio]

From: "Vern Weitzel" <vern at coombs.anu.edu.au>
> http://www.alertnet.org/thenews/newsdesk/L16859093.htm
>
> Polio "could be eradicated" by end of decade
>
> LONDON, Nov 16 (Reuters) - New vaccine strategies could wipe out lingering 
> reservoirs of polio in northern India and lead to global eradication of 
> the crippling disease by the end of the decade, scientists said on 
> Thursday.
>
> The infectious illness has been eliminated in developed nations but 
> persists in Uttar Pradesh and Bihar in India and in parts of Nigeria, 
> Afghanistan and Pakistan.
>
> Now experts have identified a simple change in the way people are 
> vaccinated that could help wipe it out.
>
> "We won't go into the next decade with polio," said Dr Bruce Aylward, 
> director of the Global Polio Eradication Initiative at the World Health 
> Organisation (WHO).
>
> Aylward, Dr Nicholas Grassly and Dr Christophe Fraser of Imperial College 
> London told reporters that switching to a monovalent vaccine against the 
> dominant strain in India from the standard trivalent vaccine that protects 
> against three types of polio virus is the key.
>
> In a study published in the journal Science they said the virus has been 
> so persistent, despite good immunisation coverage in northern India, 
> because of overcrowded living conditions and poor sanitation.
>
> Those conditions in Uttar Pradesh and Bihar made the oral poliovirus 
> vaccine less effective than in other parts of India and immunised children 
> were still being infected.
>
> The three strains in the trivalent vaccine can interfere with each other 
> inside the body, producing immunity to one strain but not another.
>
> "We were able to confirm there is a relatively easy fix by means of a 
> monovalent vaccine," said Fraser.
>
> FINAL PUSH
>
> Aylward believes the new vaccine strategy, along with improved vaccination 
> coverage, political will and surveillance, will help eliminate the 
> remaining reservoirs in the four nations and achieve the goal of the 
> Global Polio Eradication Initiative that was launched by the WHO in 1988.
>
> Polio, which is incurable, leads to irreversible paralysis. Death occurs 
> in about 5-10 percent of paralysed patients when their breathing muscles 
> are immobilised.
>
> Since the WHO eradication drive, cases have dropped from 350,000 in more 
> than 125 endemic countries in 1951 to about 1,500 cases so far this 
> year -- the lowest number ever.
>
> But as long as reservoirs of the virus exist, there is a danger of 
> transmission to other countries. Twenty-five previously polio-free 
> countries were reinfected between 2003-2005, according to the WHO.
>
> "This study has been extremely helpful in showing this disease can be 
> eradicated," Aylward said.
>
> He added that there will be a major effort in the first part of 2007, 
> despite a $100 million funding gap, to knock out the type 1 strain of the 
> virus, which is the most prevalent worldwide, and then a mopping up of the 
> type 3 strain.
>