This is the third post devoted to polio. The others I've written so far are:
- It makes sense to vaccinate against a disease that we have no more?
- Polio eradication ... and the rumors: the tsunami.
Before starting with the theme of this post, I would add a piece of news which concerns the previous posts about polio, one in which I consider the argument of the epidemic in Indonesia after the tsunami.
I wrote to Dr. David Hipgrave that at the time the epidemic was the program director for health and nutrition of the 'UNICEF Indonesia (currently the director of health, nutrition, water, environment and sanitation UNICEF China) that in the meantime I sent the material. He said that in the region of Aceh (which is most affected by the tsunami), the cover for the third dose of DPT vaccine (diphtheria, tetanus and pertussis) was 48.5%. This information was found during a survey made in September 2005, nine months after the tsunami. Dr. Hipgrave told me that the coverage of DPT vaccine and measles vaccine is also indicated for coverage OPV3 (3 doses of oral polio) because the vaccines that are part of EPI (Expanded Programme on Immunization ) are administered together. He also stressed that the region of Aceh in Indonesia was not the only one with such low vaccination coverage.
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Before you continue reading the article, I inform you that since 10.1.11, the Veneto Region has developed an online questionnaire for parents on vaccinations.
Please participate in and run the link as much as possible.
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who sent me the figures you see in the Aceh region, there were a total of six cases (the first dates back to August 31, 2005 and last until February 2006 which was also 'Last of the epidemic in Indonesia). Since then there has been no polio cases to date, thanks to mass vaccination.
I hope to be able to demonstrate that the argument of the anti-vaccination to the outbreak of polio in Indonesia after the tsunami is to be discarded.
Today I'll feature of the virus in the vaccine orally to repurchase la virulenza, attraverso una retromutazione. Questo rarissimo evento viene molto spesso riportato dagli anti-vaccinisti come esempio della "pericolosità" dei vaccini in generale.
Premetto che, come avevo già scritto negli altri post, in Italia nel giugno 2002 il vaccino orale SABIN è stato sostituito dal SALK che contiene virus inattivati e che quindi non può in nessun modo provocare la paralisi.
Parto, come al solito, dal libro "bambini super-vaccinati" del dott. Eugenio Serravalle. A pagina 106, nel capitolo sulla polio si legge:
"Un esempio di epidemia da virus vaccinico è quella verificatasi nella Repubblica Dominicana and Haiti in 2000-2001 (1). 17 cases were notified in children under the age of 6 years, of which six were fully or partially vaccinated, six were not, nothing is known of the other five. The disease was caused by a virus type 1 vaccine used in the campaign and remained in circulation in the environment by removing the faeces. Here too, it happened that the vaccine virus had changed its genetic structure, and had regained the characteristics of neurovirulence. It 's a phenomenon now well known (2): Sabin viruses can mutate and cause epidemics of virus known as "Sabin-like": it happened in the Caribbean, the Philippines, Angola, Madagascar, Indonesia, Cambodia in Niger, Myanmar and Nigeria, countries with hygienic conditions that promote the fecal-oral transmission (3) "
It 's true that in the countries listed there have been outbreaks of polio virus in which the oral vaccine had regained their virulence, making in all and for all wild poliovirus. But it does record the fact as the author of the book, without further explanation and without seeing the whole picture does not allow the reader to give due weight to information.
Note the paradox in being opposed to the vaccine, to deny his merits in the strong reduction (99% worldwide) and the eradication of polio from most countries, only to cry "wolf!" when the exact same virus appears in a population, for the mere fact that its origin is the vaccine .
Let me explain: if the poliovirus circulating in a population of non-attenuated and therefore dangerous, in the end -level management of the epidemic and danger to the public no matter where they come from, have the same mode of transmission, both of which can cause paralysis and for both there is only one way to protect children immunized with the vaccine.
According to vaccinia but the wild poliovirus has disappeared on its own (because they could never admit that the vaccine has to do in some way) but the poliovirus with the same characteristics suddenly becomes a threat as if it were somehow a supervirus. But a population that was already released by wild poliovirus with its own strengths (as they say), without the help of the vaccine as "ineffective" because now suddenly the same people is seriously threatened by the virus from the vaccine ? It should not be able to resist him as he had done - on the theory of vaccinia - with wild virus several years ago? If the population is unable to compare the virulent virus from the vaccine changed, as he had done so to free themselves from wild-type virus? Let's see what
the conditions known to give rise to an epidemic caused by a virus from the vaccine.
Mainly there are two:
1) the circulation of wild poliovirus be stopped
2) immunization coverage must be very low for a long time
So far, all outbreaks of vaccine virus c 'were these assumptions. When the coverage is very low and the wild-type virus no longer circulates, the virus vaccine that meets constantly susceptible (= non-vaccinated) has many opportunities to replicate. Over time the virus through a gradual change until a bad day, the progeny of the vaccine virus will regained full strength of the wild virus, that against which the vaccine is directed in the first place. And from that moment you begin to notice the movement of the vaccine virus, which for years was silent: it becomes evident when diagnosed the first case of paralysis. As soon as there
the first report, organize mass vaccination to protect all children from polio at the same time. In this way outbreaks are stopped. The genetic line of the mutated virus is extinguished in the absence of susceptible population with immunity to the vaccine.
has never been notified of the outbreak virus vaccine in areas with high vaccination coverage.
All these explanations for example, can read the document that Dr. Serravalle himself quotes in his book as a source for the example of the epidemic in the Dominican Republic and Haiti . Therefore be presumed to have read that document, namely:
poliomyelitis Dominican Republic and Haiti, "Weekly Epidemiolocical Record No. 2000 P. 75. 397
Instead he preferred to return to this Weekly Epidemiological Report (WER) only the information that I mentioned above. He writes a few things that do not correspond to what we read in the Weekly Epidemiological Report referenced:
In the original document is read instead:"There were 17 reported cases in children under the age of 6 years, of whom 6 were fully or partially vaccinated, 6 were not, nothing is known of the other 5."
"Between 12 July and 18 November, a total of 19 persons with acute flaccid paralysis (AFP) Have Been Identified in the Dominican Republic (Including 3 laboratoryconfirmed cases with poliovirus type 1 isolates.) Sixteen (84%) AFP cases are Less Than 6 years of age, and the age distribution ranges from 9 months to 21 years. All cases are unvaccinated Either (14) or inadequately accinated ( 5) . In Haiti, one single laboratory-confirmed poliovirus type 1 case has been reported to date, with paralysis onset on 30 August. This case is aged 2 years and was inadequately vaccinated . Despite intensive case-finding activities, no additional cases have been identified to date." [grassetto aggiunto]
Traduzione:
"Fra il 12 luglio e il 18 novembre nella Repubblica Dominicana sono stati identificati un totale di 19 persone with acute flaccid paralysis (AFP ) ( referred to in 3 were isolated poliovirus type 1). Sixteen (84 %) cases AFP have less than 6 years . The age goes from 9 months to 21 years . All cases are or unvaccinated
(14 ) o non adeguatamente vaccinati (5 ). A Haiti , ad oggi, il poliovirus del tipo 1 è stato confermato in un singolo caso, c on esordio della paralisi il 30 agosto . Si tratta di un bambino di 2 anni , non adeguatamente vaccinato . Nonostante intense ricerche, ad oggi non sono stati individuati ulteriori casi."
Quindi su 19 casi di paralisi flaccida 14 had not been vaccinated and 5 were not properly vaccinated. I have not found any trace of the "6 fully or partially vaccinated" and even the 6 "which we know nothing" . The WER say instead that among the cases of flaccid paralysis none had been completely vaccinated, ie none had completed the basic course of vaccination.
Another important sentence from that report:
The Differences in nucleotide sequences Among the virus outbreak isolates suggest That Has Been circulating for about 2 years in an area WHERE immunization coverage is very low, and the virus That HAD That's accumulated genetic changes restored the essential properties of wild poliovirus.Traduzione:
Le differenze di sequenze nucleotidiche tra i virus isolati durante l'epidemia suggeriscono che il virus sta circolando da circa 2 anni in un area con una copertura vaccinale molto bassa [grassetto aggiunto] , e che aveva accumulato mutazioni genetiche e così riacquistato le proprietà essenziali del poliovirus selvaggio.
The key factor for control of circulating OPV-derived viruses is the same as thatTraduzione:
required for control of circulating wild polioviruses: achieving and maintaining high immunization coverage. No evidence for circulation of OPV-derived virus has ever been found in any area with high coverage. The current outbreak is a powerful reminder
that even polio-free areas need to maintain high coverage with polio vaccine until global polio eradication has been achieved.
Il fattore chiave per il controllo dei virus derivati dal vaccino OPV is the same that is required for the control of wild poliovirus circulation: achieving and maintaining high immunization coverage. No evidence for the circulation of the virus from OPV vaccine has ever been found in areas with a high vaccination rate. The current outbreak is a powerful reminder that even polio-free areas should maintain high immunization coverage against polio, until you reached the goal of eradication.
This risk of OPV is still seen in the context and weighed with great advantages of oral vaccine antopolio. I quote from the WHO web site :
- Negli ultimi 10 anni in tutto il mondo ( al settembre 2007 ) , sono stati somministrati più di 10 miliardi di dosi di vaccino antipolio orale a più di 2 miliardi di bambini.
- Nello stesso periodo , in 9 paesi ci sono stati nove focolai causati da virus vaccinale (VDPV) , in comunità con bassa copertura vaccine, causing a total of 200 cases of polio.
- same time , more of 33 000 children were paralyzed by wild poliovirus while more than 6.5 million cases of polio have been avoided by the oral polio vaccine
feature of OPV to be able to mutate and become virulent again and able to move among the population when conditions are favorable (see above), is naturally reckoned by experts working for the eradication of polio and is integral part of eradication .
Main:
Polio vaccines and polio immunization in the pre-Eradication era - WHO position paper
Weekly Epidemiological Report No. 85 June 4, 2010, p. 213-228
Who - Online Q & A
What is Vaccine Derived Poliovirus
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