The purpose of this trial is to obtain serum for proficiency testing to confirm assay validity is maintained following the dosing of adults with a pediatric dose of HIL-214.

This single-arm trial serves to obtain serum for proficiency testing to confirm assay validity is maintained. Exploratory aspects of this trial include evaluating additional assays used for the assessment of immune responses to HIL-214 in peripheral-blood samples. Given the large volume of blood required, the pediatric dose will be tested in healthy adults. The main scientific rationale for the trial is to identify immune assays that can assess the generation of serum antibodies or cell-mediated immunity (CMI) specific to norovirus strains not represented in the HIL-214 vaccine (i.e. cross-reactivity).

Inclusion Criteria:

• Male or female subjects aged 18 to 49 years, inclusive.
• Individuals who are in good health at the time of entry into the trial as determined by medical history, physical examination (including vital signs) and clinical judgment of the investigator.
• The individual signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any trial procedures, after the nature of the trial has been explained according to regulatory requirements.
• Individuals willing and able to comply with trial procedures and are available for the duration of follow-up.

Exclusion Criteria:

• Females who are pregnant or breastfeeding.
• Gastroenteritis within 14 days before planned dosing (can warrant delay of trial vaccine administration).
• Known hypersensitivity or allergy to any of the HIL-214 components (including excipients).
• Known or suspected impairment/alteration of immune function, including history of any autoimmune disease or neuro-inflammatory disease.
• Any serious chronic or progressive disease (including hepatitis B or C).
• Previous exposure to an experimental norovirus vaccine.
• Subject or subject's first-degree relatives are involved in the trial conduct.

Safety Analysis Set, all participants that received trial vaccine (HIL-214).

Serious adverse events, all-cause mortality and other significant adverse events were assessed for each participant from Day 1 to Day 85

Solicited AE (local and systemic) data was collected for 79 participants.