Sierra Leone’s race against COVID-19 Vaccine Shelf Life

Sierra Leone recorded its first positive COVID19 case in March 2020.  A year later the country received its first batch of 96,000 doses of the AstraZeneca-Oxford COVID-19 vaccine shipped via the COVAX Facility, a partnership between the Government Sierra Leone, CEPI, Gavi, UNICEF and WHO.

Finally having access to the vaccines was great, but their arrival also highlighted a major weakness in the health care system’s cold supply chain which is essential for keeping the vaccines safe and effective.

Sierra Leone isn’t alone in being challenged with this cold storage problem.  An article in NPJ Vaccines Journal published in 2021 noted that cold storage is a critical problem for low income countries (LICs).

“Strict regulations for temperature are critical for the maintenance of efficacy, potency, and stability of vaccines. These are significant challenges in LICs due to a shortage of cold chain infrastructures and a lack of advanced technology to monitor the cold chain for storage, distribution, and transportation of vaccines, especially in the rural regions. It could result in low immunization coverage in these areas and, subsequently, the probable endemicity of COVID-19 infections” the authors wrote.

However, for Sierra Leone, if there is one bright spot to come out of the recent COVID-19 health crisis, it is that it has given the economically low-income country (LIC), an opportunity to significantly boost its cold-chain capacity through financial investment   received during the COVID-19 vaccination process.

The COVID-19 pandemic, has given the country an opportunity to purchase about 500 equipment essential to the cold storage chain, said Dr. Tom Sesay, who at the time was the  Child Health /Expanded Program on Immunization (CH/EPI)  program manager.  These have been distributed to various health facilities and most districts have received in excess of 30 to 40 equipment.

Throughout 2021, UNICEF with support from GAVI, USAID and JICA procured and delivered 430 solar powered refrigerators to primary health care facilities, 22 large solar refrigerators in all district vaccine stores, one ultra-cold-chain freezer and one Walk-In-Cold Room at central level. 

These refrigerators are an important contribution to health facilities such as Senthani Peripheral Health Unit, in Kambia District, north of Sierra Leone that have operated for a long time without adequate cold chain equipment.

In addition, a cadre of 32 technicians and 32 supervisors were trained in effective cold chain and vaccine management for each of the four approved vaccines which are being administered in Sierra Leone. 

Also, around 900 data-entry clerks received training on effective data entry management practices, while 1, 385 social mobilisers   were trained in communication, interpersonal skills, misinformation and rumour management, and provided with updated key messages to help increase vaccine uptake through allaying fears and hesitancies about the vaccines.

Sesay noted initially the process of addressing the COVID-19 pandemic was quite challenging fraught various challenges such as administration of vaccines, lack of funding, and cold-chain logistics and storage management.

All these contributed to the putting a lot of pressure on the health care workers because of the limited time they had to administer donated vaccines that had a short shelf life. Also, added to this was the time it was taking to address hesitancy challenges from the population, he said.

He offered as an example of what they had to deal with in the beginning, the donation of the COVID-19 vaccine Oxford-Astra Zeneca.

The vaccine was received through a donation to the African Union’s African Vaccine Acquisition Task Team (AVATT) by South Africa, “From acquiring with lot of delay in that process, by the time the vaccines arrive in Sierra Leone the shelf life was about one month and we were not able to use all that consignment of vaccines and it ended up expiring.”

However, he added, “That was an isolated incidence and for the others that we got we have been able to use them before expiring” he said.

Dr Sesay recalled that, it was difficult at the start of the COVID-19 vaccination campaign due to lack of resources, “We had issues with transportation and printing of the Vaccination Cards. Later, we had some resources mainly through World Bank, UNICEF and NaCOVERC.”

Partner support has been critical in assisting the government of Sierra Leone address the COVID-19 pandemic.

“The country is challenged to procure vaccine and rely on donor support. It has been facing the challenge of access, some countries have it and by the time they decide to give to the country it would have only one-month shelf life” said Dr Samuel Williams, WHO Immunization health officer in Sierra Leone.  “It’s a donation and when you receive it you try to utilise it between the remaining shelf life.”

The WHO Office in Sierra Leone offers the Ministry of Health and Sanitation (MoHS) technical advice, guidance on vaccine administration, and general guidance on communication. It also sources funds to procure items such as data gadgets, manage funds from donor like GAVI for and on behalf of government. “Such funds may also be required when they want to do surge,” Dr. Williams noted.

He said in Sierra Leone the preference has been increasingly towards vaccines that have a longer shelf life, thus away from AstraZeneca which initially had to be stored  at between 2C and 8C and  had a shelf-life of six months.  (In April 2022, AstraZeneca announced that the Food and Drug Administration of Thailand (Thai FDA) has approved an extension to the shelf-life for COVID-19 Vaccine AstraZeneca (ChAdOx1-S [Recombinant]) to nine months, with immediate effect.)

Yuki Suehiro, UNICEF Sierra Leone Chief of Health and Nutrition, believes that a sustainable COVID-19 vaccine deployment is dependent upon the availability of a standard cold chain system for effective vaccine management.

Suehiro noted that the refrigerators procured for health facilities, each with a storage capacity of 36 litres, will provide adequate storage for essential life-saving vaccines and enhance the productivity and efficiency of health workers in hard to reach communities.

Mohamed Jalloh, District Health Officer at the Pujehun District Medical Health Team in southern Sierra Leone, said the district’s cold room has enough refrigerators including those used for the mobile vaccines they take to the different chiefdoms. He said each chiefdom headquarter within the district has a functioning  refrigerator to store vaccines at required temperature levels and that  health staff collect it from there and move into the communities for inoculation.

Given that the vaccines have different storage temperatures, the health care workers have to pay close attention, Jalloh noted.

For example, the Pfizer vaccine cannot be kept for a long periods in the peripheral health unit (PHU) level as it should be kept on a minus freezing point. Pfizer COVID-19 vaccine frozen vials can be stored at either –90 °C to –60 °C or 2-8 °C upon receipt. After thawing, the shelf life is 31 days at 2 °C to 8 °C. Undiluted vaccine vials can be stored at up to 30 °C for 2 hours (including thawing time).

So, what that means, he explained, is that “When taken from national (the national COVID facility) say on the first of July it should be only stored for a month period. So, from national to Pujehun even if the expiry date has not been reached it must be destroyed because it has taken one month outside the freezing point.”

In terms of the most  preferred vaccines for the rural area, Jalloh said they are all preferable but with regards storage facilities among the four types of vaccines currently available, AstraZeneca is being brought to the district when it has almost reached its expiry date and it doesn’t last long in the fridge.  

“With Sino Pham, Johnson & Johnson (J&J) they have a longer shelf life in the refrigerator, Jalloh noted, adding that “some people prefer J&J because it is one dose. We are using more J&J when we go to outreach areas in difficult terrains as it is more preferable.

Dr. Williams at WHO noted that   “The science behind the vaccine is changing, we are guiding the Ministry of Health on that” as that is being updated. For example, he said the J&J vaccine was to change from a one to a two dose administration.

While addressing the COVID-19 pandemic has been challenge, a positive for Sierra Leone, is that the improvements made in its cold storage supply change equipment, procedures, and capacity building of people working in the sector will be a positive for the overall health care system.

“Those  (newly purchased) equipment, will in the long term help us with storage not only with the COVID-19 vaccines,  but other vaccines stored in the right environment, that is one of the areas we have a very positive impact in the pandemic response” said Dr. Sesay.

JIJ/ wr

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