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This has been a very mixed year for the global polio eradication campaign.
The good news is that two of the three strains of wild poliovirus have been conquered; they no longer exist except in laboratories.
The mixed news is that the remaining wild poliovirus only exists in two countries, Afghanistan and Pakistan. However, the number of cases in both countries, especially in Pakistan, has been higher than in 2018. The two countries suffered 125 cases of polio compared to just 33 last year, 101 of those in Pakistan. In both countries, strife, insecurity and anti-vacccination propaganda and rumors have enabled the virus to hold on.
The bad news is that the number of people--mostly children--sickened by poliovirus that has mutated back to a virulent form from the live-but-attenuated polio vaccine has more than doubled since 2018. This back-mutation only occurs in one person out of an estimated 2.8 million, but since 450 million children are getting the attenuated vaccine every year, a significant number of cases are inevitable as long as the oral vaccine remains in wide use--unless the surrounding population has a very high rate of "herd immunity." There were 241 such cases in 2019 vs. just 104 in 2018.
The solution is complex, but at hand. In part, it depends on the rapid release of an oral vaccine against the type 2 poliovirus, which is expected to be less likely to mutate to a virulent form. You can read about the global polio endgame strategy here. Plans and resources are in place to make this transition, and the intense, decades-long global campaign to wipe out this deadly disease once and for all will succeed, even if not quite as quickly as hoped.
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REA
What the global polio eradication campaign
wants never to happen again
The good news is that two of the three strains of wild poliovirus have been conquered; they no longer exist except in laboratories.
The mixed news is that the remaining wild poliovirus only exists in two countries, Afghanistan and Pakistan. However, the number of cases in both countries, especially in Pakistan, has been higher than in 2018. The two countries suffered 125 cases of polio compared to just 33 last year, 101 of those in Pakistan. In both countries, strife, insecurity and anti-vacccination propaganda and rumors have enabled the virus to hold on.
The bad news is that the number of people--mostly children--sickened by poliovirus that has mutated back to a virulent form from the live-but-attenuated polio vaccine has more than doubled since 2018. This back-mutation only occurs in one person out of an estimated 2.8 million, but since 450 million children are getting the attenuated vaccine every year, a significant number of cases are inevitable as long as the oral vaccine remains in wide use--unless the surrounding population has a very high rate of "herd immunity." There were 241 such cases in 2019 vs. just 104 in 2018.
The solution is complex, but at hand. In part, it depends on the rapid release of an oral vaccine against the type 2 poliovirus, which is expected to be less likely to mutate to a virulent form. You can read about the global polio endgame strategy here. Plans and resources are in place to make this transition, and the intense, decades-long global campaign to wipe out this deadly disease once and for all will succeed, even if not quite as quickly as hoped.
-----
REA
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