Poliovirus can cause crippling disease with devastating consequences. Thanks to global polio eradication efforts, more than 17 million people are able to walk today who would have otherwise been paralyzed for life by this virus. Since 1988, there has been a 99% decline in polio cases. However, according to the World Health Organization (WHO), as many as 200,000 new cases a year could emerge over the next decade if we fail to eradicate the disease.
Even if a single polio case remains anywhere, children all over the world are at risk. Failure to stop transmission of poliovirus in endemic areas threatens a re-emergence of this vaccine-preventable disease.
Pakistan, Afghanistan and Nigeria are the last remaining strongholds of endemic poliovirus transmission. According to the Global Polio Eradication Initiative (GPEI), Pakistan had reported a total of 24 new cases of polio this year as of June 19. This number is twice as high as the total number of cases reported in 2018.
New cases of polio were reported recently in Khyber Pakhtunkhwa province. Positive environmental samples for poliovirus were also found in Quetta, Balochistan, on May 20. Experts are concerned that the increase in polio cases in Pakistan could lead to the export of the disease to other countries and threaten the three-decade-long efforts to eradicate polio.
The wild-type poliovirus was also found in environmental samples in Sistan and Baluchestan province in Iran, which borders Pakistan and Afghanistan; these samples were collected on May 20. The reappearance of poliovirus in Iran, where routine vaccination coverage is very high, shows the threat of the international spread of polio virus beyond Pakistan and Afghanistan. The threat of importation of polio into countries where the disease has been eradicated is real. This was seen from 2002 to 2005 when a specific strain of poliovirus traveled from country to country, causing many outbreaks.
The threat of importation of polio into countries where the disease has been eradicated is real. This was seen from 2002 to 2005 when a specific strain of poliovirus traveled from country to country, causing many outbreaks
In the recent past, Pakistan has faced several attacks on polio vaccination workers after rumors spread by Taliban and religious conservative leaders. In 2012 and 2013 several polio workers were targeted in Pakistan by Taliban forces, killing 16 workers. One of the worst attacks came in April this year when a video was circulated in social media spreading rumors about reactions to the polio vaccine while an inoculation campaign was ongoing.
According to reports, 25,000 kids were taken to hospital because of fear and panic in Khyber Pakhtunkhwa province on April 22. Several polio workers were attacked, and polio eradication campaign had to cease. Since then, polio vaccination has been restarted, but many believe significant damage has already been done. According to reports, rumors were further fueled by the broadcasting of anti-vaccine video on local media.
There is overwhelming scientific evidence that vaccines are extremely safe and are the most effective intervention to prevent diseases. Anti-vaccine campaigns are damaging efforts to control and eradicate diseases all over the world. In the United States, the re-emergence of measles is a prime example. The re-emergence of vaccine-preventable diseases is threatening communities all around the world. Social media provide a platform for anti-vaccine campaigners to present and disseminate inaccurate and misleading information. In the era of social media, rumors can spread very rapidly and can cause mass panic, as seen in the recent incidents in Pakistan.
To combat this issue globally, health-care professionals and public health officials need to partner with the social media platforms. Removing anti-vaccine material from Google, Facebook, YouTube and Twitter would be an important step.
In March, the American Medical Association issued a letter to Amazon, Facebook, Google, Pinterest, Twitter and YouTube, urging them to ensure their users have accurate and scientifically sound information about vaccines. Facebook, Pinterest, Twitter, Amazon and YouTube all have released statements to stop the spread of misinformation on their platforms, and efforts are ongoing. Similar efforts are needed in areas where polio vaccination programs are being targeted. Local governments need to partner with local media, conservative leaders, and social media to make sure people have access to scientifically sound information.
This year, a weaker form of polio (vaccine-derived poliovirus) was reported in Nigeria, Niger, Ethiopia and the Democratic Republic of Congo. The US Centers for Disease Control and Prevention (CDC) recommends that for the eradication of this form of polio, oral polio vaccine (OPV) should be replaced with an inactivated polio vaccine (IPV) for routine inoculations in countries where wild-type poliovirus has been eradicated. These recommendations have not been fully implemented yet because of the global shortage of IPV.
The World Health Assembly has called for the development of a more affordable and safer IPV. Because of the shortage of this type of vaccine, experts have suggested the use of a fractional (one-fifth) dose of IPV. This expert recommendation is supported by a recent study done in two clinics in Dhaka showing that two such fractional doses of were more immunogenic (16% to 36% higher response compared with regular IPV). Fractional polio vaccine is an excellent alternative in countries facing an IPV shortage, allowing them to use their IPV supplies most effectively.
Once the last case of polio is eradicated, aggressive surveillance and continued vaccination in endemic areas will be needed for years. To ensure that the transmission of polio is completely stopped, we will have to continue intensive environment surveillance for years after the last known case of the poliovirus. The job of polio eradication is not even close to complete until the last case of this crippling disease is seen.