NUVA and Syadem

The Unified Nomenclature of Vaccines (NUVA) is designed to compile comprehensive vaccination histories from both digital and physical sources. The aim is to build precise and interpretable vaccination records that can be used by information systems to manage patient care and vaccination recommendations.

NUVA's nomenclature consists of:

1. Core Concepts: Vaccines and valences.
2. Binding Concepts: Target diseases and external codes.

Binding concepts represent elements found in other terminologies, allowing NUVA to be both a standalone system and a bridge to external coding systems.

The core concepts are central to NUVA's purpose.

1. Vaccines: These codes represent vaccination events at their highest precision level, such as fully qualified products (e.g., BOOSTRIXTETRA), combinations of valences (e.g., Tdap), or vaccines targeting a specific disease (e.g., rabies vaccine). Unlike valences, vaccines are not represented hierarchically; they are immediate descendants of the Vaccine concept.
2. Valences: A valence is the minimal functional unit characterizing a vaccine, typically representing a combination of antigens aimed at the same target disease and a dose. For example, for pertussis, valences include:
   • aP: Acellular pertussis, standard dose.
   • ap: Acellular pertussis, low dose.
   • wP: Whole cell pertussis.

Valences are designed to reflect real-world vaccine production. Abstract valences are also used for degraded information scenarios, such as:

• Per: Pertussis valence, unspecified.
• Acel: Acellular pertussis vaccine, dose unspecified.

These abstract valences serve as parent categories to the more detailed real valences.

Binding concepts are crucial for integrating NUVA with external coding systems. They help ensure the completeness of a standalone NUVA release while facilitating mappings to other terminologies. This feature is vital for maintaining interoperability and enhancing the utility of vaccination records across different systems.

1. Target Diseases: These represent the vaccine-preventable diseases and are linked to the corresponding valences. All target disease concepts are immediate descendants of the Disease concept. The concept code for a disease is Dx/Dxx, where x/xx is a one or two-digit number, with labels expressed in multiple languages.
2. External Codes: These correspond to the representation of vaccines in other coding systems. External codes are organized by code system and may include pharmaceutical codes (CIS, CIP, PZN, CNK), logistical codes (GTIN), international vaccine codes (SNOMED-CT, ATC), and national vaccine codes (CVX, THL Rokotevalmisteet). Each external code maps to one and only one vaccine code in NUVA, maintaining the same level of precision. The concept code for an external code is CSYS-Code, where CSYS identifies the code system and Code is the code value.

A new NUVA code is only created if a difference in vaccination impacts the evaluation and recommendation for subsequent vaccinations. For instance, while National Drug Code (NDC) product codes might differ based on packaging size, this distinction is irrelevant for NUVA since it doesn't affect vaccination efficacy. Similarly, vaccines manufactured by different organizations but functionally identical may share the same NUVA code.

NUVA uses a tree structure for valences, enabling detailed characterization of vaccines. For example, the MMR vaccine contains three valences for measles, mumps, and rubella. When mapping to another system, NUVA identifies the valences and assigns the appropriate NUVA code. If no matching NUVA code exists, a new one is created to capture the unique valence set.

Concept codes for valences are formatted as VALxxx (e.g., VAL001 for a specific valence), and for vaccines, they are formatted as VACxxxx (e.g., VAC0001 for a specific vaccine). This structured approach ensures consistency and clarity in coding.

Syadem is responsible for developing and maintaining NUVA. The organization focuses on creating a public good through NUVA, ensuring it is kept up-to-date by a community of experts. Syadem's work with NUVA is pivotal for clinical decision support (CDS) systems in various countries, enabling accurate vaccination recommendations and tracking.

NUVA aims to provide stable, long-term codes that can be used to track a patient's vaccination history accurately over decades or even centuries. This stability ensures that patient records remain interpretable and reliable, regardless of changes in vaccine production or naming conventions.