THOUSANDS of Tanzanian children remain vulnerable to a number of life-threatening diseases due to incomplete immunisation with the recommended pentavalent vaccine, a new study has confirmed.

Dr Robert Tillya, a senior researcher at Ifakara Health Institute made this assertion when profiling a new study conducted by IHI experts in partnership with the World Health Organization (WHO).

The research leading to the study focuses on the pentavalent vaccine, which provides protection against diphtheria, pertussis (whooping cough), tetanus, hepatitis B and Haemophilus influenza type B, a bacterium that can cause severe infections such as meningitis, he stated.

Recently published in the journal Vaccines, the study exposes a concerning shortfall in vaccine completion that compromises child health across the country, he explained, noting that the findings show that while most children begin the vaccination process, not all complete it.

That leaves them vulnerable to entirely preventable diseases, he said, pointing out with his colleague Dr Abdallah Mkopi, said that the research surveyed 4,403 caregivers of children aged 12 to 23 months in 2019.

The study found that 91.5 percent of children received the first dose of the pentavalent vaccine, but while 89.4 percent completed the full three-dose schedule, there was a national dropout rate of 2.3 percent, he said.

“While this figure may appear small, it represents a significant number of children unprotected against serious illness when scaled across the population,’ he said.

The study also revealed notable regional differences, as in Zanzibar the dropout rate was just 0.9percent, compared to 2.4 percent on the Mainland. “These figures suggest disparities in access, healthcare delivery or awareness between the regions,” he further noted.

The research identified several factors behind the failure to complete vaccination schedules, as children from poorer households were significantly less likely to complete all three doses, he pointed out, noting that this is often due to indirect costs such as transportation to health centres.

Additionally, whether the primary caregiver was male or female influenced vaccine completion rates, although the study did not explore the reasons in depth. Caregivers with limited formal education were also less likely to complete the vaccination schedule, possibly due to a lack of awareness about the importance of receiving all three doses, the study noted.

The 2.3 percent dropout rate, though seemingly minor, leaves thousands of children exposed to vaccine-preventable diseases and risks reversing hard-won gains in child health, it cautioned.

The study calls for targeted health education particularly for expectant mothers during antenatal and postnatal visits, alongside improved access to vaccination services for low-income families.

Dr Tillya and his colleagues advocate for stronger outreach and community engagement, particularly in marginalised areas, as well as support for caregivers to understand and complete vaccination schedules.

With sustained support from WHO and the health authorities, the country has a clear path to closing the immunisation gap and ensuring all children are protected from these five deadly diseases, the lead author underlined.