“The first day of the drive required parents to bring their kids to the booth to administer polio drops, while health volunteer themselves go from house to house to administer the vaccine on days 2 and 3. So usually we see parents not turn up for the first day as they can get their children vaccinated at home itself on the remaining days. This does not mean that they are resistant to vaccines. I have personally had fathers call me up saying that their child had been left out or that the booth had run out of vaccines. This is a pattern we have been seeing in the last few years,” DMO Dr Sakeena told TNM.

On 20 January, 77,467 kids received immunisation and 75,169 children received the immunisation on 21 January.

By 22 January, 4,09,159 kids were immunised. All other districts of Kerala, however, recorded more than 94 percent immunisation in this drive, with at least five districts recording 100 percent immunisation.

Malappuram's demographic pattern and the health department’s limited human resources too contribute to the additional mop-up days that the district sees.

“While in other districts, each volunteer may have to administer drops to 5,000 to 7,000 children, in Malappuram this ratio is very high. In some areas, the ratio of target population per volunteer is as high as 13,000 and this is a difficult target to achieve within 3 days, as these volunteers also have to update the data and ensure that all eligible children have been covered,” she added.