‘COVID-19 vaccines are safe’: however, the issues of vaccine equity and data equity remain

Introduction

The most extensive global vaccine safety study included data from ninety-nine million people (Faksova et al., 2024). However, the issues of vaccine equity and data equity remain. The COVID-19 pandemic showed that gross inequities in population morbidity, mortality, and access to medicines persist between nations, reflecting colonial histories and the current political status of international governance. Large-scale vaccine safety studies are also victims of such historical maladies.

The latest study uses vast data sets to ensure vaccine safety. According to a new study by Faksova et al. (2024) involving 99 million people, it is the most extensive global vaccine safety study. The Global Vaccine Data Network (GVDN) utilises vast data sets to detect potential vaccine safety issues. The study, ‘COVID-19 vaccines and adverse events of particular interest’, was authored by 24 researchers from 10 collaborator sites across eight countries (Australia, Argentina, Canada, Denmark, Finland, France, New Zealand and Scotland). According to the report’s authors, the safety of the COVID-19 vaccine outweighs the risks, notwithstanding sensational reports. This study’s findings have also been reported widely in the popular media (99 Million People Included, 2024; Covid Jab Study, 2024).

Data fairness and data equity

Does the large sample size of a study automatically address the issues of data fairness and data quality? The authors, collaborating institutions, and the data are mainly from the Global North, sharply focusing on the issue of ‘data equity’, which refers to the use of data through an equity lens of how data is collected, analysed, interpreted, and distributed. It underscores marginalised communities’ unequal opportunities to be included in the data. ‘There are also concerns about ‘fairness’ today whenever data-driven systems are used, as data is no longer believed to be impartial and neutral.

Hawkes et al. (2021) reported that during the early phase of the COVID-19 pandemic, fewer countries than ever before reported sex-disaggregated data across all WHO-recommended indicators. They observed that these results suggested that the failure to consistently evaluate and report on available data is a more significant issue than resource capacity or lack of data availability when reporting sex-disaggregated data (Hawkes et al., 2021).

The visibility of underrepresented groups has been historically suppressed in the data records. For example, confirmed COVID-19 cases require testing, and there can be racial disparities in the availability of testing and in the desire of individuals to be tested, leading to systematic biases in the collected data (Jagadish et al., 2021). Moreover, the benefits of scientific collaboration are too often skewed towards wealthier countries (Horn et al., 2023).

The benefits of risk outweigh the risks

Since 2020, more than 13.5 billion COVID-19 vaccine doses have been administered worldwide, and 71% of the global population has received at least one dose.

This study evaluated the risk of Adverse Events of Particular Interest (AESI) following the COVID-19 vaccination at ten sites across eight countries. This observational cohort study used a common protocol to compare the ‘expected rates of 13 selected AESI across neurological, haematological, and cardiac outcomes. Expected rates were obtained by participating sites using pre-COVID-19 vaccination healthcare data stratified by age and sex’. Observed rates were reported from the same healthcare datasets since the COVID-19 vaccination program rollout. AESI occurs up to 42 days following vaccination with mRNA (BNT162b2 and mRNA-1273) and an adenovirus vector (ChAdOx1).

National regulatory authorities have granted complete or emergency use authorisations for 40 COVID-19 vaccines. The data reported in this study is mainly from developed countries. The study took place in a specific context of global vaccine inequity.

Though the Global Vaccine Data Network (GVDN) study had a broad-based institutional partnership of 24 authors, data and institutional partnerships are absent from countries like South Africa and India, where the COVID-19 vaccine has covered significant populations. Both countries have well-established and reputed researchers and research establishment institutions, and including researchers and data would have contributed to a greater understanding of the genetic susceptibility of vaccines.

India has administered over 2.2 billion doses, including the currently approved vaccines’ first, second, and precautionary (booster) doses. The Serum Institute of India is one of the largest producers of Oxford-AstraZeneca COVID-19 vaccines and vaccine suppliers to several African countries. South Africa currently uses two vaccines: the one-dose Johnson & Johnson and the two-dose Pfizer. According to the South African government’s Department of Health 39,289,966 people have been vaccinated against COVID-19.

Faksova et al. (2024) report that the benefits still outweigh the risks. Out of the 99 million studied, reported side effects were unusually rare and limited to less than ten people. The Australian study confirmed an increased risk between receiving an AstraZeneca vaccine and Acute Disseminated Encephalomyelitis (ADEM). The reported prevalence of ADEM after a COVID-19 vaccine was 0.78 cases per million vaccines.

However, Luo et al. (2016) reported adverse events in Different age groups using big clinical trial data. At the population level, there is a significant adverse event variance. In clinical trial studies, children and older patients are more susceptible to adverse events. Luo et al. (2016) reported that the adverse event incidence rate in clinical trial studies is as high as 27.0% at the population level, which is higher than the reported incident rate in various patient care settings (7%-20%). Age-associated adverse events should be considered in planning, monitoring, and regulating clinical trials (Luo et al., 2016).

Limitations of multi-country analysis

COVID-19 is one of the truly global pandemics. One of the strengths of this study is its large sample size, drawn from eight countries among the 194 member states of the WHO. The multi-country analyses are susceptible to population confounding factors, such as differences in pre-existing health conditions, genetic factors, ethnic profiles, and behavioural patterns, which were not adjusted for in the analysis. The approach used by Faksova et al. (2024) in their study needs to be revised to understand and monitor data equity and health inequity. Their approach applies to large datasets representing average populations in developed countries. Even then, they should have attempted age- and sex-desegregated data adjusted for factors like co-morbidities.

Vaccine nationalism has consequences

Scientists started designing potential vaccines just a few hours after the initial SARS-CoV-2 genome sequence was made public during the COVID-19 pandemic. The wealthiest nations have secured billions of COVID-19 vaccines while developing economies struggle to access supplies. In Europe and the United States, major vaccination programmes had started by the end of 2020 through the voluntary WHO COVID-19 Vaccinations Global Access (COVAX) programme; high-income nations committed to distributing vaccinations but fell short of their obligations. High-income nations obstructed the plan for months when South Africa and India requested an urgent waiver of intellectual property rights about COVID-19 vaccines from the World Trade Organization, allowing each nation to begin production. By the end of 2021, low- and middle-income countries will have lost anywhere from 200,000 to 1.3 million lives due to wealthier nations’ unwillingness to work together.

Currently, over one-third of the world’s population has not received a single dose, and the death toll resulting from vaccine nationalism continues to grow (Carlson et al., 2024).

Faksova et al. (2024) The study identified the pre-established safety signals for myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the thin sac covering the heart) after mRNA vaccines, Guillain-Barré syndrome (muscle weakness and changed sensation (feeling), and cerebral venous sinus thrombosis (type of blood clot in the brain) after viral vector vaccines.

The study identified possible safety signals for transverse myelitis (inflammation of part of the spinal cord) after viral vector vaccines and acute disseminated encephalomyelitis (inflammation and swelling in the brain and spinal cord) after viral vector and mRNA vaccines.

Observed versus expected analyses are used to detect potential vaccine safety signals. These studies look at all people who received a vaccine and examine if there is a greater risk of developing a medical condition in various periods after getting a vaccine than before the vaccine became available.

The lead author, Kristýna Faksová, remarked that using a common protocol and aggregating the data through the GVDN makes studies like this possible. ‘The population size in this study increased the possibility of identifying rare potential vaccine safety signals’, she explains. Single sites or regions are unlikely to have a large enough population to detect rare signals”. However, publicly available data dashboards may provide greater transparency and more robust communications to the health sector and the public.

International partnership for COVID-19 vaccine research

The Global Data Vaccine Network (GVDN) is a coordinated global effort to assess vaccine safety and effectiveness so that vaccine questions can be addressed more rapidly, efficiently, and cost-effectively. The group has several studies underway to build upon our understanding of vaccines and how we understand vaccine safety using big data.

The GVDN was established in 2019. With data from millions of individuals across six continents, the GVDN collaborates with renowned research institutions, policymakers, and vaccine-related organisations to establish a unified, evidence-informed approach to vaccine safety and effectiveness (99 Million People Included, 2024).

The GCoVS Project is supported by the Centers for Disease Control and Prevention (CDC) of the U.S. Department of Health and Human Services (HHS) to allow for the comparison of vaccine safety across diverse global populations as part of a financial assistance award totalling US$10,108,491, with 100% funding from the CDC and HHS. Interestingly, this study reports no authors, institutions, or data from the USA.

In addition to seeking a thorough understanding of vaccine safety and effectiveness characteristics, the GVDN) works to improve immunisation policies and enable international decision-making. To promote a better understanding of the safety and efficacy of pandemic-related products for population subgroups, GDVN must ensure vaccine and data equity in their future endeavours through equitable representation, considering racial, ethnic, and gender diversity across the life cycle. These initiatives are also intended to help address geographical, socioeconomic, and health disparities.

Broad-based research collaborations and data equity are essential to saving lives in the next pandemic. Future global research partnerships must be truly global.

Author contribution

JT contributed to the conceptualisation and Writing of the original draft. FH contributed to writing, review & editing the editorial. Both authors reviewed and accepted the final changes before resubmission.

Data availability statement

Data sharing is not applicable – no new data is generated.