POST 01354E: POLIO ERADICATION—LET’S FINISH THE JOB FOLLOW UP ON POSTS: 01339E
, 01345E, 01346E
20 NOVEMBER 2008
NEED TO JUDICIOUSLY USE THE DIFFERENT OPVS
There is no single oral poliovirus vaccine (OPV) presentation that is equally effective for each currently circulating wild poliovirus type (WPV1 & WPV3). Monovalent type 1 OPV (mOPV1) is many-fold times more effective per dose against WPV1 than trivalent vaccine (tOPV). 
mOPV1 was used preferentially in supplementary immunization activities (SIAs) in 2006-2008, particularly in India and Nigeria, to focus on interruption of WPV1 transmission.
Mogens Munck’s observations on total case numbers of WPV1 and WPV3 in 2007 and 2008 to date reflect what happened in those two countries.
WPV3 trends in India in 2007 and 2008 indicate that yes, Mogens, mOPV1 does not protect against WPV3. The WPV3 outbreak reached its peak late in 2007 and is being controlled with SIAs with monovalent type 3 OPV while mOPV1 is still predominantly being used. Nigeria is responsible for more than ¾ of reported WPV1 cases in 2008 to date despite continued mOPV1 SIAs and routine immunization (RI) with tOPV – both of which nonetheless left a large residual proportion of unvaccinated and undervaccinated children in core areas of the country.
Authorities in each polio-affected country will need to judiciously use the different OPVs subnationally in SIAs. The global priority remains the elimination of WPV1 as soon as possible. A bivalent type 1 & 3 vaccine is under evaluation, which may provide another tool that will ease the balancing act, if appropriately effective in combination.
All would agree with the position paper from the Indian Academy of Paediatrics (IAP) shared by Robert Steinglass on the need for a strong, sustainable RI program throughout India. The areas globally now experiencing WPV circulation are among the worst in RI coverage historically and currently and deserve earnest investment. But polio eradication cannot wait for substantial changes in RI coverage. IAP affirms the indication that the mOPVs may succeed in the interruption of both types of WPV. There is one issue stated in the paper with which I disagree: basically only some few northern European countries -- with a very different WPV epidemiology -- achieved polio elimination using IPV alone; all the rest of the world used OPV before elimination was reached and only gradually have some of these countries stopped use of OPV for exclusive use of IPV, mostly after 2000.
Steven Wassilak ([[email protected]
Global Immunization Division
Centers for Disease Control and Prevention
LET’S FINISH THE JOB
I was following the interesting discussions over the last several correspondences concerning polio eradication (stop or continue!). I totally agree with Hans' point of view and I would like to mention the experience of Sudan when the NIDs were stopped in 2003 because the wild poliovirus circulation has been interrupted for around 3 years. MOH focused on routine immunization, but with sub-optimum coverage. In the following year, an importation of a wild poliovirus into Sudan caused a massive outbreak of poliomyelitis in the country and further the virus was exported to the neighbouring countries on the eastern/southern sides of Sudan (Ethiopia, Eritrea, Somalia, Yemen, Saudi Arabia and Indonesia). Around 18 months without SIAs resulted in crippling over 150 children in Sudan only and costed the global programme several millions of US$. Therefore, let's believe in it and work together to finish the job.
Salah Haithami ([[email protected]
Congratulations to Dr Hans Everts for his article.
Dra. Lucia Linares ([[email protected]
WHO EPI NPO
WHO Mozambique Country Office 
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