By Treezer Michelle Atieno
Immunization is recognized as one of the most successful and cost-effective public health interventions in history, saving approximately two to three million lives each year. The polio vaccine is one such intervention.
“Polio is a highly contagious viral disease that affects the nervous system and can lead to complete paralysis within a short period. The virus is transmitted primarily through person-to-person contact, with the most common route being ingesting contaminated food or water. It multiplies in the intestines,” explains Dr. Samuel Usman, the Global Senior Technical Advisor at the CORE Group Partners Project (CGPP) in Nigeria.
He adds that the initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and limb pain.
Africa was declared free of wild poliovirus (WPV) in August 2020. This remarkable accomplishment was the result of decades of collaboration between international health organizations, national and local governments, civil society, and community volunteers.
However, Africa continues to face outbreaks of the non-wild variant of poliovirus, known as circulating vaccine-derived poliovirus (cVDPV), in 25 countries. Additionally, in 2022, two countries that had been polio-free for over three decades, Malawi and Mozambique, reported imported cases of WPV.
In Nigeria, cVDPV2 was detected in 18 states in 2021. Since then, the World Health Organization (WHO) and partners of the Global Polio Eradication Initiative (GPEI) have been collaborating to strengthen immunization coverage by using both the fractional Inactivated Polio Vaccine (fIPV) and the novel oral polio vaccine type 2 (nOPV2).
“The oral polio vaccine which a child takes in two drops stimulates the body’s immune system. When the vaccine reaches the blood in the form of low components of the polio virus, the antigens in the vaccine for all the three types of the virus stimulates the body’s system to produce antibodies that remain in the body,” says Dr. Usman, adding that these antibodies are responsible for fighting the real polio virus when a child is exposed to it.
The polio vaccine should however be administered while still potent (able to protect against polio) as Dr.Ado Muhammad, the Global Director of D-8 Health and Social Protection Programme notes.
“Vaccine Vial Monitors (VVMs) on the polio vaccine indicate the potency stage of the vaccine. Stages one and two are good to use while stages three and four are spoilt and should not be used. Usually, when the vaccine reaches the third stage, it means the cold chain is broken,” says Dr. Muhammad.
Throughout Africa, governments and donors have made progress in ensuring life-saving vaccines are available. However, the challenge lies in maintaining the proper conditions for vaccines as they make their way to the most remote areas.
Cold chain management is a crucial component of an effective immunization program, ensuring the potency of vaccines throughout the supply chain. It involves various storage and transport measures like cold rooms, freezers, refrigerators, cold boxes, and carriers that maintain vaccines at the appropriate temperature throughout their journey from manufacturing to administration.
The United Nations Children’s Fund (UNICEF) emphasizes the importance of maintaining a high-quality cold chain to ensure that vaccines remain potent and effective in protecting against diseases. Vaccines must be stored within a specific temperature range from the time they are manufactured until they are administered. Deviating from this range can permanently reduce the potency of the vaccines.
In this regard, UNICEF has invested over $56 million in providing solar-powered vaccine cold-chain systems in Nigeria. This investment covers the cost of solar-powered refrigerators in all 37 states of Nigeria.
Unlike others, the Solar Direct Drive (SDD) refrigerators are wired directly to the photovoltaic generator and use solar energy to directly freeze water or other cold storage material and then use the energy stored in the frozen bank to keep the refrigerator cold during the night and cloudy days.
These refrigerators eliminate the need for batteries and therefore have the potential to resolve battery-powered vaccine refrigerator problems and help extend the cold chain into areas that might otherwise be underserved.
In Northern Nigeria, particularly, solar-powered refrigerators have come in handy for preserving the polio vaccines and ensuring that routine immunization is uninterrupted.
The region has a total of 19 states and uptake of routine immunization (RI) has been hampered by several challenges, including poor cold chain systems.
Hajia Abaji is a community nurse at the Dutse Alhaji Primary Healthcare Centre (PHC) in the Dutse Alhaji community, situated in the Bwari Local Government Area (LGA) of the Federal Capital Territory (FCT). The community is predominantly made up of Hausa and Fulani people and is located about 30 kilometers away from Abuja’s Central Business District.
The PHC lacks the typical appearance of a health facility with no basic amenities such as water, good roads, electricity, and a telecommunications network.
Hajia’s role involves ensuring that vaccines are properly stored and available for use on immunization days at the centre. This used to be a challenging task due to irregular power supply and inadequate storage facilities. However, UNICEF donated a solar-powered refrigerator to the centre, which has greatly improved the situation.
Before receiving the solar-powered refrigerator, Hajia had to travel kilometres to the Township Primary Health Centre to collect the required vaccines for the PHC, and then return any unused ones after each day of the three-times-a-week immunization exercise.
“Even though this place is in the FCT, it is very remote and faces many socio-economic challenges. We collect routine vaccines from the Bwari Local Government secretariat during polio immunization sessions and store them in the solar-powered vaccine freezer,” explains Hajia.
The vaccination team at the Dutse Alhaji PHC only collects vaccines for the number of children to be immunized keeping in mind the monthly target population.
“Vaccines are stored in cold boxes and must be administered within 48 hours. Any leftover vaccines are stored in the solar-powered freezers that were donated to the Dutse Alhaji PHC by UNICEF,” says Hajjia.
Before the donation, the facility relied on an electric-powered refrigerator for vaccine storage and with the frequent power cuts, this refrigerator was not as reliable as the solar-powered one.
“The constant power outages led to the wastage of so many polio vaccines and unreliable immunization schedules,” adds Hajjia.
In Kumbotso LGA in Kano State, Nafii Ibrahim is the routine immunization focal person for the Kumbotso PHC, which also relies on four solar-powered refrigerators for storing polio vaccines.
“Before we began using this refrigerator, the cold chain officer had to travel to Aminu Teaching Hospital for vaccines, which took 50 minutes by tricycle,” says Nafii. She further explains that this situation frequently resulted in delays in the commencement of immunization, thereby hindering them from achieving their daily target. The Kumbotso PHC supplies vaccines to 11 wards in the LGA namely Challawa, Chiranchi, Danbare, Danmaliki, Guringawa, Kumbotso, Kureken Sani, Mariri, Na’ibawa, Panshekara and Unguwar Rimi.
“The vaccines are transported by air in refrigerators to the National Strategic Cold Store in Abuja. From there, they are transferred to the Zonal Cold Stores, then to the State Cold Stores, and finally to the LGA Cold Stores. Each of these facilities has a complete cold chain system with appointed cold chain officers,” explains Nafii.
Kumbotso PHC has a register of cold chain monitoring officers who ensure that the solar-powered refrigerators are working effectively 24 hours a day.
“During routine immunization days, the cold chain officers transport the vaccines in cold boxes, using a tricycle, to the community hospitals. Afterward, the Volunteer Community Mobilizers distribute the vaccines to the children,” says Nafii.
The immunization supply chain in Nigeria includes national, zonal, state, and LGA facilities. The National Strategic Cold Store (NSCS) is located in Abuja, while the zonal cold stores are in Bauchi, Minna, Kano, Lagos, Enugu, and Warri.
Each state and LGA has its cold stores in their respective capital cities, and health facilities are distributed throughout the wards in the LGAs.
Currently, there is at least one solar direct-driven Refrigerator per ward in approximately 9,750 PHCs in Nigeria.
“UNICEF has invested in this project to modernize and optimize supply chains and support Nigeria in scaling up access to higher-performing Cold Chain Equipment. This is to meet the increased vaccine storage capacity requirements, not only for polio vaccinations but also for new vaccine introductions and associated immunization activities as part of system strengthening,” explains Protus Bwile, who is part of the UNICEF health team in Nigeria.
According to Bwile, solar-driven refrigerators have increased effectiveness by offering user-independent freeze-free protection technologies and demonstrated performance at higher ambient temperatures.
This has improved the management and optimization of vaccine delivery, storage, and safeguarding of vaccine potency in the immunization supply chain systems.
“The number of children reached for polio vaccination has increased. For example, over 60 million children were vaccinated during the NIPD in November 2023. The solar-powered refrigerators are also climate resilient and environmentally friendly as they contribute to the reduction of carbon emissions,” says Bwile.
Dr. Muyi Aina, the Executive Director of the National Primary Health Care Development Agency (NPHCDA), states that Nigeria requires 125,450 litres (L) of negative storage and 150,000L of positive storage annually at the national level.
Dr. Aina explains that the national, zonal, and state stores are equipped with ultra-cold chain (UCC) equipment, Walk-In-Cold-Rooms (WICRs), and Walk-in-Freezer-Rooms (WIFRs). Meanwhile, the LGAs’ cold stores and health facilities are provided with chest freezers and Solar Direct Drive (SDD).
Similarly, in 2021, UNICEF delivered 800 ultra-cold chain freezers to nearly 70 countries, with a storage capacity of 200 million mRNA vaccines.
Data shows that since 2019, the Nigerian Government has continued to make an annual incremental provision for vaccine financing through a service-wide vote, with a 34.2 percent increase between 2019 (US$60.7 million) and 2023 (US$148.1 million).
The government plans to build on this progress through the inclusion of vaccine financing as a first-line charge item on the national budget. This is a more sustainable funding source as it will be a statutory allocation from consolidated revenue, and the release will not be subject to bureaucratic delays.
The Nigerian government is also taking steps to improve the storage capacity gap in the country, given the increasing population and introduction of new vaccines.
As part of this effort, they have launched a national storage expansion project called the ‘Three-Hub Project.’ The project involves expanding the Abuja, Kano, and the Lagos cold stores to meet the country’s cold chain capacity needs until 2035.
On May 18, 2023, Nigeria’s former Minister of Health, Dr. Ehanire, conducted a groundbreaking event to mark the start of construction for the Abuja Hub. All the hubs are expected to be completed by December 2025.
Dr. Mustapha Mamuond, a public health expert from Abuja, emphasized the importance of political will and significant investment to strengthen Nigeria’s cold-chain facilities, noting that it is crucial for public health.
“Nigeria must ensure enough funds are regularly allocated to operationalize the vaccination program. We also need to invest in modernizing vaccine supply chains and management to ensure that the right doses of the appropriate vaccines are available at every vaccination session. It’s crucial to invest in innovations that can overcome barriers to accessing vaccinations,” he said.
This reporting is supported by the United Nations Foundation Polio Press Fellowship.
