Vaccine derived polio outbreak a week after WHO announce wild polio had been eradicated

[Amity Island]

A new polio outbreak in Sudan has been linked to the oral polio vaccine that uses a weakened form of the virus.
News of the outbreak comes a week after the World Health Organization (WHO) announced that wild polio had been eradicated in Africa.
The WHO linked the cases to a strain of the virus that had been noted circulating in Chad last year and warned that the risk of spread to other parts of the Horn of Africa was high.

In a statement on the new cases, the WHO said two children in Sudan, one from South Darfur state and the other from Gadarif state, close to the border with Ethiopia and Eritrea, were paralysed in March and April. Both had been recently vaccinated against polio.
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The WHO said initial outbreak investigations showed the cases were linked to a continuing vaccine-derived outbreak in Chad that was first detected last year and is now spreading in Chad and Cameroon.

Vaccine-derived polio spreads in Africa after defeat of wild virus

Fresh cases of disease linked to oral vaccine seen in Sudan, following outbreak in Chad

www.theguardian.com

Circulating vaccine-derived poliovirus type 2 – Sudan

On 9 August 2020, the Federal Ministry of Health, Sudan notified WHO of the detection of a

www.who.int

 

[trophywench]

Well is it summat up with the 'vaccine' eg virus not modified sufficiently (can one call it a vaccine if they don't vaccinate with it??) or has the virus changed?

 

[Robin]

Well is it summat up with the 'vaccine' eg virus not modified sufficiently (can one call it a vaccine if they don't vaccinate with it??) or has the virus changed?

Babies given the 'live' vaccine excrete it in their nappies. In places with poor sanitation, and where the parents may not have been vaccinated, they can catch polio from the dirty nappies. Then,( as the Guardian article explains, and this was the bit I didn’t realise), as the modified strain gets passed on again, it can mutate into a fuller strength one.
I think this is why there are conspiracy theories in some developing countries that Western governments are trying to repress them all by killing them with the vaccines.

 

[trophywench]

Oh. Heck.

 

[Amity Island]

Babies given the 'live' vaccine excrete it in their nappies. In places with poor sanitation, and where the parents may not have been vaccinated, they can catch polio from the dirty nappies. Then,( as the Guardian article explains, and this was the bit I didn’t realise), as the modified strain gets passed on again, it can mutate into a fuller strength one.
I think this is why there are conspiracy theories in some developing countries that Western governments are trying to repress them all by killing them with the vaccines.

Robin,
I take it that this means that the vaccine shouldn't be given in places with poor sanitation and/or where the parents haven't already got immunity? If so, why is it been given in those circumstances?

 

[Robin]

Robin,
I take it that this means that the vaccine shouldn't be given in places with poor sanitation and/or where the parents haven't already got immunity? If so, why is it been given in those circumstances?

If you read the Guardian article in the original post, it explains that whilst it’s preferable now to give the dead vaccine by injection, which solves the problem, in some places where sanitation is questionable, it’s safer to give the oral vaccine, where syringes and needles can’t be sterilised. And giving any sort of vaccine is better than not vaccinating at all, presumably.

 

[Bruce Stephens]

And giving any sort of vaccine is better than not vaccinating at all, presumably.

So as is common, it's a balance. I'm reminded of the most recent episode of Cautionary Tales https://timharford.com/etc/more-or-less/ which talks (mostly) about smallpox. The early vaccines (and similar) were horribly dangerous, but still often a major advantage compared to risking smallpox.

 

[Amity Island]

If you read the Guardian article in the original post, it explains that whilst it’s preferable now to give the dead vaccine by injection, which solves the problem, in some places where sanitation is questionable, it’s safer to give the oral vaccine, where syringes and needles can’t be sterilised. And giving any sort of vaccine is better than not vaccinating at all, presumably.

Thanks for your reply Robin