• Immunity gaps critical obstacle to eradication efforts, experts say.
• Polio vaccine refusal surged in areas like Pesahwar, parts of Karachi.
• Karachi, Quetta, Peshawar called core reservoirs of polio transmission. 

ISLAMABAD: A report by the Institute for Disease Modeling (IMD) has raised alarms about escalating wild poliovirus cases in Pakistan, fearing that the number could hit 55 to 65 by the end of 2024.

This growing threat is compounded by missed vaccinations, refusals and ongoing issues within the national polio eradication programme, according to the report.

Pakistan has so far recorded 28 wild poliovirus cases in 2024, with Balochistan leading the count at 16 cases, followed by Sindh with seven, Khyber Pakhtunkhwa with three and one each in Punjab and Islamabad.

The virus continues to circulate in environmental samples from multiple regions, signalling persistent transmission risks.

Experts point to immunity gaps as a critical obstacle to eradication efforts. Thousands of children have been missed in immunisation drives, while refusals have surged, particularly in areas like Peshawar and parts of Karachi.

In these districts, refusals by parents have reached alarming levels, driven by misinformation and mistrust in the vaccination programme. Logistical challenges, such as accessing remote areas, have also contributed to the growing number of unvaccinated children.

Moreover, experts estimate that 2-3% of children have consistently been missed during vaccination campaigns in each district of Pakistan. Although this percentage seems small, it represents hundreds of thousands of vulnerable children, particularly in densely populated and under-served areas like Karachi East and Quetta Block. Sanitation issues in these areas further exacerbate the spread of the virus.

Anwar-ul-Haq, National Coordinator for the Emergency Operations Centre (EOC), highlighted the long-standing presence of the virus in Karachi, Quetta and Peshawar, calling them core reservoirs of polio transmission.

“The virus has circulated for over 16 months in some areas,” Anwar said, adding that many children in these regions remain unvaccinated despite intensified efforts. He explained that detections of the virus elsewhere in Pakistan are genetically linked to these high-transmission zones.

Balochistan, particularly the Quetta Block, remains an area of concern due to insecurity and poor healthcare access which have severely impacted vaccination efforts. The IMD report underscores the importance of conducting high-quality vaccination campaigns in these reservoirs to prevent a surge in polio cases.

A senior government official added, “The programme has always remained transparent in reporting cases as well as issues. However, complacency hit every component of the programme, including Acute Flaccid Paralysis (AFP) surveillance. Since mid-2023, we’ve seen a serious surge in environmental detections not corresponding to the polio cases. The new management notified a ‘surveillance for eradication’ task team, which has revitalised AFP surveillance, now efficiently picking up cases.”

Further complicating the situation, the real issue began in 2021 when a non-government accountable coordinator was placed in the programme, the official said. This move weakened the government’s writ over the programme’s implementing partners, WHO and Unicef, leading to fragmented operations and poor communication efforts.

“While 2-3% of children in each district were officially recorded as missed, a much higher proportion went unreported, creating wide immunity gaps, particularly in Balochistan, Khyber Pakhtunkhwa and Sindh,” the official explained.

The official added that predicting the number of future cases depends on whether the virus finds children with significantly low immunity. “It also depends on the success of the upcoming campaigns to reach all children and give a quick immunity boost, especially to those with borderline immunity. However, at the current trajectory, more children are likely to be affected by WPV1 in clusters.”

The current leadership in Pakistan’s polio eradication initiative has adopted a more transparent approach than in previous years, openly acknowledging systemic problems. Officials admit that data manipulation and mismanagement have plagued the campaign in the past, hampering its effectiveness.

Unlike previous administrations, the current leadership reports all cases fitting the polio definition, even in cases where children test positive for the virus but do not develop paralysis.

However, as Anwar clarified, “It’s important to remember that AFP by definition involves ‘sudden onset of paralysis,’ so the surveillance is not picking up cases without paralysis but rather more atypical and mildly symptomatic cases due to improved surveillance.”

The polio eradication programme is undergoing internal accountability measures. Hundreds of personnel, including senior officials, supervisors, data operators and vaccinators, have been dismissed for irregularities such as data manipulation. This cleanup is seen as essential to restoring public trust and ensuring the programme’s integrity moving forward.

Despite the challenges, the programme remains cautiously optimistic. A “2-4-6” plan, designed to conduct high-quality vaccination campaigns in the coming months, could help contain the virus in its strongholds of Karachi, Quetta and Peshawar. However, the detection of poliovirus in environmental samples from previously unaffected areas adds a layer of complexity.

International bodies, including the Global Polio Eradication Initiative (GPEI), have urged Pakistan to urgently address its immunity gaps, refusals and missed vaccinations. The detection of the virus in environmental samples across the country underscores the risk of wider transmission, not only within Pakistan but across its borders.

Officials say that the next few months are critical. If Pakistan fails to control the virus this year, the global eradication efforts could be jeopardised. There is a real risk of the virus spreading to neighbouring countries, reversing years of progress.

Health authorities must urgently address the immunity gaps and logistical challenges that have long hindered vaccination efforts. Without immediate action, Pakistan could see a significant rise in polio cases by the end of 2024, which would be a devastating setback for the country and the global fight against polio.

— Originally published in The News