CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
The COVID-19 illness is known for its highly contagious nature and rapid transmission. It is caused by a viral pathogen called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The term "coronavirus" comes from the Latin word "corona," which means crown, referring to the virus particles' appearance resembling round structures with projections resembling the solar corona when observed under an electron microscope (Cascella et al., 2022; Dhar Chowdhury and Oommen, 2020).
Originating in Wuhan City, Hubei province, China on December 8, 2019, COVID-19 has had a devastating global impact. With a death toll exceeding 6 million worldwide, it is considered the most significant global health crisis since the influenza pandemic of 1918 (Younes et al., 2020; Cascella et al., 2022). On December 31, 2019, the World Health Organization (WHO) received information regarding COVID-19. Subsequently, on January 30, 2020, the WHO declared it a global health emergency, and on March 11, 2020, it was officially classified as a global pandemic. This classification had not been made since 2009, when the H1N1 influenza was declared a pandemic (Cennimo, 2023). Since being categorized as a global pandemic, the SARS-CoV-2 virus, which causes COVID-19, has spread to 223 countries. To date, there have been over 593 million reported cases and more than 6 million deaths worldwide.
Despite worldwide efforts to administer COVID-19 vaccinations, there is currently no effective treatment available for the disease. Vaccination is considered a critical measure in preventing and managing COVID-19, playing a significant role in controlling the global epidemic. However, even with widespread vaccination, the SARS-CoV-2 virus continues to circulate. Similar to other vaccines, the protective effectiveness of COVID-19 vaccines diminishes over time after completing the vaccination process.
Based on a meta-analysis conducted by Feikin et al. (2022), the effectiveness of vaccines against SARS-CoV-2 infection diminishes by 21% from one month to six months after the initial vaccination. However, research studies conducted by Zeng et al. (2022) and Zhou et al. (2022) indicate that administering booster doses leads to higher antibody levels in individuals, providing enhanced protection against the virus. As a result, many countries are currently implementing strategies for administering booster doses to improve overall vaccination rates among their populations.
The ongoing COVID-19 epidemic is characterized by the continuous and rapid mutation of the SARS-CoV-2 virus. As of August 13, 2022, the World Health Organization (WHO) has identified five variants of concern (VOCs): Alpha (identified on December 18, 2020), Beta (identified on December 18, 2020), Gamma (identified on January 11, 2021), Delta (identified on May 11, 2021), and Omicron (identified on November 26, 2021) (WHO, 2022). Currently, the dominant strain driving the global outbreak has shifted from the Delta variant to the Omicron variant.
In comparison to the previously dominant Delta variant, the Omicron variant displays a higher number of significant mutations, with up to 32 mutations in the spike protein. Some of these mutations may contribute to immune evasion and increased infectivity. However, overall, the Omicron variant is associated with milder symptoms and significantly fewer cases of severe hospitalization or death compared to earlier variants.
Recent research studies, conducted both domestically and internationally (Saban et al., 2022; Chemaitelly et al., 2022), have demonstrated the effectiveness of booster shots. These studies indicate that COVID-19 vaccination substantially reduces the rate of infection, hospitalization, and mortality caused by various SARS-CoV-2 variants. Vaccination plays a crucial role in preventing and controlling outbreaks.
The effectiveness of vaccines against symptomatic infections caused by the Omicron variant is approximately 50% during the first three months after receiving the second vaccine dose. However, the vaccines remain highly effective in preventing hospitalization and death due to Omicron infection, with rates exceeding 70% after the second dose and over 90% after receiving the booster dose. Overall, current vaccinations continue to provide protection against the evolving variants (Zhu et al., 2022).
Aside the technological and medical hurdles involved in vaccine production, one of the major challenges is storage requirements of the COVID-19 vaccine. The requirement for refrigeration or cryogenic storage of biological drugs and vaccines is not novel, but the demand experienced a substantial surge during the COVID-19 pandemic. The Pfizer vaccine previously necessitated ultra-low temperatures ranging from −60°C to −80°C, while the Oxford-AstraZeneca vaccine mandates a storage and transportation temperature between 2-8°C (Acharya et al., 2021). Nonetheless, this posed a significant obstacle in distributing these vaccines to remote regions lacking the essential infrastructure to sustain such extreme temperatures. To tackle this challenge and streamline distribution, the US Food and Drug Administration (US FDA) declared on February 25, 2021, that vaccines could be transported and stored at more adaptable temperatures that can be easily upheld using pharmaceutical freezers (Sun et al., 2022). Nonetheless, many low-income countries (LICs) still face challenges in maintaining and monitoring the required temperatures during vaccine transportation and storage due to inadequate infrastructure (Nadimuthu and Victor, 2022).
This study aims to examine the challenges and prospects associated with the storage of COVID-19 vaccines, shedding light on the critical factors impacting their effectiveness and overall success of vaccination programs.
1.2 Statement of the Problem
Maintaining the integrity of COVID-19 vaccines is essential to ensure their safety and efficacy. Vaccines are complex biological products that can be susceptible to degradation if exposed to unsuitable storage conditions, such as extreme temperatures, light, or improper handling (Centers for Disease Control and Prevention, 2023). The efficacy of different COVID-19 vaccines, such as those based on mRNA, vector-based platforms, or protein subunits, can vary, making proper storage guidelines crucial to preserve their immunogenicity and potency. This study aims to examine the challenges and prospects associated with the storage of COVID-19 vaccines. Understanding the challenges and prospects of COVID-19 vaccine storage is vital for optimizing vaccine delivery and mitigating the impact of the ongoing pandemic.
1.3 Aim of the Study
The aim of this study is to examine the challenges and prospects associated with the storage of COVID-19 vaccines.
1.4 Objectives of the Study
The specific objectives of this study are as follows:
- To identify and analyze the key challenges in storing COVID-19 vaccines.
- To investigate the prospects for improved vaccine storage.
- To provide insights and recommendations for optimizing vaccine storage and distribution to enhance global vaccination efforts against COVID-19.
1.5 Research Questions
- What are the primary challenges associated with storing COVID-19 vaccines?
- What are the prospects for improved vaccine storage?
- What measures can be implemented to optimize vaccine storage and distribution, taking into consideration the challenges identified and the prospects for improvement?
1.6 Research Hypothesis
(H0): The challenges in storing COVID-19 vaccines are not significant, and there are prospects for improving vaccine storage.
(H1): The challenges in storing COVID-19 vaccines are significant, with limited prospects for improvement in vaccine storage.
1.7 Justification of the Study
The COVID-19 pandemic has had a profound impact worldwide, necessitating the rapid development and deployment of vaccines. Understanding the challenges and prospects of vaccine storage is crucial for effective vaccine distribution and administration, ultimately contributing to the control and mitigation of the pandemic.
1.8 Scope of the Study
The study will focus on COVID-19 vaccine storage challenges and prospects in the Nigerian context. The study will primarily focus on the storage challenges and prospects associated with COVID-19 vaccines that have been authorized or approved for emergency use by relevant regulatory authorities.
