According to the World Health Organization (WHO) vaccination prevents between 2 and 3 million deaths each year and, alongside clean drinking water, is one of the most successful public health interventions in preventing infectious diseases. While the widespread use of vaccines has led to the decline of many diseases, there are still many people, especially children, who should be vaccinated but are not. This can be attributed to multiple factors: issues with vaccine access (temporary shortages or other barriers that hinder or prevent vaccination) or vaccine hesitancy, which causes people to delay or refuse vaccination.
Argentina boasts one of the most comprehensive vaccination schedules globally, covering a wide range of needs from childhood to adulthood, including specific vaccines for pregnancy and international travel3. Despite this comprehensive program, vaccination coverage, while relatively high, still falls short of reaching the entire target population, reflecting a trend seen worldwide.4
In light of this, in 2019, the Bunge and Born Foundation (B&B Foundation) set out to annually survey vaccine confidence levels in the Argentine population and identify the barriers people face in successfully accessing vaccination. With the onset of the pandemic in 2020, and especially the crisis of misinformation that followed, it became clear that analyzing these aspects (confidence and access) is essential to understanding what drives variations in coverage rates. This led to the development of the Vaccine Confidence and Access Index (VCAI).
Methodologically, the VCAI is built on data collected through a nationwide survey targeting individuals aged 15 and older. The survey utilizes a structured questionnaire administered via an Interactive Voice Response (IVR) system: mobile phone users receive a call with a recorded voice posing questions and providing answer options, which participants select by pressing the corresponding numbers on their phones. The survey is representative of the diversity of the country in terms of geography, age, gender, and education levels, among other parameters. The total sample size for the survey is approximately 7,000 complete responses in each measurement applied yearly.
From the collected data, two indices are developed: one for confidence and another for access. The Vaccine Confidence Index™ (VCI), part of the Vaccine Confidence Project, served as the basis for constructing the confidence index. The VCI was created in 2015 by Dr. Heidi Larson’s team at the London School of Hygiene & Tropical Medicine. For the access index, the B&B Foundation followed the guidelines set forth by the Strategic Advisory Group of Experts (SAGE) in 2022, which provide a series of key points for analyzing access conditions. These guidelines were adapted to the Argentine context and methodology for proper implementation.
Among the most notable findings from recent measurements, particularly in relation to the confidence dimension, is the significant drop in confidence levels in 2020, which have not recovered to pre-pandemic levels:
Additionally, a second observation reveals a more pronounced decline in confidence among younger respondents (those aged 15 to 20):
Regarding the access index, in its second measurement (the new methodology was implemented in 2022), two important aspects also stand out. First, there is a decrease in the overall access index, which highlights a significant opportunity for improving access conditions:
Finally, and even more concerning, are the results on access levels based on educational attainment, which show that those with lower educational levels face the worst access conditions. This is particularly worrying, given that education level is a reliable proxy for socioeconomic status.
These are just a few examples of the valuable insights generated by the VCAI. Recognizing the importance of this type of study and the rigorous methodology behind it, the journal Vaccine recently published the findings, along with the methodological standards used in the development of the index.
The significance of these measurements, which have been conducted continuously from 2019 to the present, lies in generating knowledge useful to society at large, and particularly to public policy decision-makers. Through the VCAI, they can access up-to-date, detailed information on vaccine confidence and access levels. The B&B Foundation hopes that this information will contribute to improvements in the design of immunization programs and strategies and guide a more efficient allocation of human and financial resources within the framework of public health policies.
Reference
- https://www.who.int/health-topics/vaccines-and-immunization#tab=tab_1
- https://ourworldindata.org/vaccination
- “Entender la infodemia y la desinformación en la lucha contra la COVID-19”. Organización Panamericana de la Salud, 2020.
- Vaccine Confidence Project: https://www.vaccineconfidence.org/
- For more information: http://currents.plos.org/outbreaks/index.html
- SAGE recommendations were published on the 17th December 2021 epidemiologic publication https://apps.who.int/iris/handle/10665/350649?locale-attribute=es&
- To access the full article: https://doi.org/10.1016/j.vaccine.2024.06.037
