About the GVDNThe GVDN makes it possible to perform retrospective analyses of health data
The Global Vaccine Data Network (GVDN) is an international consortium for vaccine safety research that currently consists of 21 partners in 17 countries.
The GVDN seeks to address the following:
- Scope of data to properly understand and demonstrate vaccine risk vs benefit in different populations and individuals
- Lack of infrastructure and capabilities to monitor and evaluate vaccine outcomes in low to middle income countries
- Delays in collating vaccine usage data to inform decisions during global pandemic events
- Readily accessible, evidence-based material for use in communications
The GVDN makes it possible to perform global collaborative retrospective analyses of health data utilising the existing capabilities of some partners, while growing the capacity of countries with less developed data infrastructures. Sharing of standards and common data protocols will facilitate robust and rapid scientific outputs that will contribute strong evidence to the dialogue around vaccine use and safety. The global scale will provide even greater precision in understanding vaccine outcomes. Furthermore, development of data capabilities designed to explore more individualised aspects of vaccine safety may help to ascertain the genomic basis for variability in response to vaccines.
Recently the use of large administrative databases that contain interactions with health services has become easier. Vaccine safety research relies on being able to identify the exposure to a vaccine. Rare events that may be associated with vaccines need very large populations because:
- Serious adverse events are very rare
- There is wide variability in the types and manufactures of vaccines used in different countries
- We need to explore the risk in subgroups such as older people and children.
The first study planned by the GVDN will cover an underlying population of almost 2 billion person-years.
How can big data help assess vaccines
- Collections of routinely collected health data already exist in many countries. These collections are diverse, containing useful information such as hospitalisations, pharmaceuticals including vaccines, pregnancy and birth over time.
- Collaborations between organisations holding different data within a country, for example, the Vaccine Safety Datalink, or across countries within a continent such as VAC4EU, are examples of the successful use of this data for meaningful advances in the knowledge of vaccine safety and effectiveness as well as vaccination coverage and cost effectiveness.
- Randomised controlled trials (RCT) are usually used to assess vaccine safety and efficacy. However compared to RCTs, big data can provide a picture of vaccine safety and effectiveness across large and diverse groups of people and over time. This is because some groups of people are usually left out of prelicensure trials. For example, people with particular health conditions, ethnic minority groups and pregnant women. Additionally, big data can capture information over longer periods of time than RCTs. These features of big data mean identifying rare events and longer term effects is possible.
Unfortunately, in the last decade we have also seen the proliferation of vaccine safety scares promulgated widely through the internet and social media. Several such scares have derailed the polio vaccination program and other important vaccination programs including measles vaccination in the UK and HPV vaccination in Japan. Safety concerns, whether real or perceived, can spread beyond borders and severely interrupt successful vaccination programs. While vaccine hesitancy and anti-vaccine communication have become global, the ability to respond to such concerns has remained largely fractured without coordination between countries. With the advent of large clinical databases in many countries of the world and multi-country collaborations, it is now possible to standardize approaches and rapidly evaluate rare vaccine safety concerns through initiatives such as the Global Vaccine Data Network.
The last ten years has seen a dramatic expansion of the number of vaccines in use globally and in the number of manufacturers involved in the global vaccine marketplace. This expansion has had a tremendous positive impact on the health of the world’s population. The continued success of the global vaccination effort relies upon the use of safe vaccines and public confidence in both their utility and safety. For thorough and authoritative information about vaccine safety, including the immune system, different vaccine examples, vaccine doses and ingredients, and chronic conditions that some people link to vaccination, please visit the website of the Children’s Hospital of Philadelphia.