Vaccine Info

GI.1/GII.4 Norovirus Vaccine

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GI.1/GII.4 is a tablet oral norovirus vaccine candidate consisting of both Monovalent GII.4 VXA-G2.4-NS and Monovalent GI.1 VXA-G1.1-NN.  


GI.1/GII.4 is a tablet oral norovirus vaccine candidate to prevent illness from the norovirus.

Vaxart believes a vaccine that produces mucosal antibodies locally in the intestine, in addition to systemic antibodies that circulate in the blood, may better protect against norovirus infection than an injectable vaccine.


Clinical trials are underway to determine the proper dosage of the bivalent oral tablet vaccine

Clinical Trials

Clinical Trial NCT03897309: Safety & Immunogenicity Study of Ad5 Based Oral Norovirus Vaccines (VXA-NVV-103) (Recruiting)

  • VXA-NVV-103 is a phase 1B Randomized, Double-Blind, Placebo-Controlled, Multi-Center Safety and Immunogenicity Study of Adenoviral-vector Based Oral Norovirus Vaccines Expressing GI.1 or GII.4 VP1 with Monovalent or Bivalent Dosing in Healthy Adult Volunteers. The study consists of 2 parts which will enroll 86 subjects:
  • Part 1 - Double-Blind Period: Post confirmation of eligibility subjects will be randomized in a double-blinded manner to one of four treatment arms. Treatment Group 1 will contain an open-label sentinel group of 6 subjects to be enrolled prior to initiation of subsequent treatment groups. After review of the safety data and confirmation the dose is well tolerated through Study Day 8, the rest of the study will proceed in a double-blinded, randomized fashion. The 6 sentinel subjects will not be part of the 16 subjects in Treatment Group 1 to be enrolled in the double-blinded placebo-controlled cohort; randomization will be 1:1:2:1 for Treatment Groups 1 through 4 respectively.
  • Study Design and Vaccine Groups
    • Monovalent GII.4 VXA-G2.4-NS (6 sentinels / 16 randomized)
    • Monovalent GI.1 VXA-G1.1-NN (16 randomized)
    • Bivalent GII.4/GI.1 VXA-G2.4-NS + VXA-G1.1-NN (32 randomized)
    • Placebo Tablets no vaccine (16 randomized)
  • Subjects will be followed for ~4 weeks post-vaccination for safety and immunogenicity. The study database will be locked post completion of Day 29 visits.
  • Part 2 will consist of an open-label booster vaccination for the bivalent treatment group ~4 months post initial vaccination. Subjects will be followed for safety and immunogenicity for ~4 weeks post the boost.
  • All subjects will be followed for long term safety for 1-year post initial vaccination.

Clinical Trial NCT02868073:  Phase 1 Placebo-controlled, Randomized Trial of an Adenoviral-vector Based Norovirus Vaccine (Completed)

  • The study will enroll 66 subjects in four cohorts. All subjects will receive a single administration of VXA-G1.1-NN at a low dose, a high dose or placebo.
  • Two sentinel groups will enroll 3 subjects each in an open-label manner (Cohorts 1 and 3) to receive VXA-G1.1-NN prior to enrolling either of the randomized, controlled cohorts (Cohorts 2 and 4). Within the double-blinded Cohorts (2 and 4), placebo subjects will receive the same number of tablets as the vaccine subjects in that Cohort. Subjects will be enrolled and dosed in the low dose groups prior to initiation of dosing in the high dose group.
  • Cohort 1: 3 subjects at low dose Cohort 2: 20 subjects at low dose and 10 placebo Cohort 3: 3 subjects at high dose Cohort 4: 20 subjects at low dose and 10 placebo
  • Subjects will be followed for 28 days post-vaccination for preliminary immunogenicity. Subjects will continue to be followed for 1-year post-vaccination for long term safety.

Clinical Trial NCT03125473: Dose-Optimization Trial of VXA-G1.1-NN in Healthy Volunteers (Completed)

  • This study will enroll approximately 60 subjects in four cohorts of 15 subjects each. The cohorts may be enrolled and run in parallel or overlap; they do not have to run sequentially. The dosing for each cohort will be as follows:
  • Cohort 1: Multiple low dose on Days 1 and 8 Cohort 2: Multiple low dose on Days 1, 3 and 5 Cohort 3: Multiple low dose on Days 1 and 29 Cohort 4: Multiple high dose on Days 1 and 29
  • All subjects receiving study drug will have safety and immunogenicity assessments completed through Study Day 57 following their initial vaccination. Subjects may also be evaluated for persistent immunogenicity at Day 180 and will be followed for safety for 12 months following initial vaccination (Study Day 365)


Clinical Trials

No clinical trials found