Phase I Safety Study of B/HPIV3/S-6P Vaccine Via Nasal Spray in Adults

Inclusion Criteria:

1. Nonpregnant adults between 18 years and 50 years of age, inclusive.

2. General good health, without significant medical illness, physical examinationfindings, or significant laboratory abnormalities as determined by the investigator.

3. Demonstrates comprehension of the protocol procedures and knowledge of the trial bypassing a written comprehension examination (passing grade > 70%).

4. Available for the duration of the trial.

5. Willingness to participate in the study and cooperate with the study procedures asevidenced by signing the informed consent document.

6. Persons of childbearing potential must have used effective birth control methods forat least one month prior to vaccination, and agree to continue with 'per label/fullyeffective use' for the chosen method for the duration of the study (30 days prior tofirst vaccination until 12 months after first vaccination), from amongst these:

• pharmacologic/hormonal contraceptives, including oral, parenteral,subcutaneous, and transcutaneous delivery;

• condoms or diaphragm with spermicide;

• intrauterine device;

• absolute abstinence from heterosexual intercourse as a matter of normalpreferred lifestyle;

• or must be surgically sterile or have documented menopause, having had nomenses at all for at least one full year. All persons of childbearing potential must provide samples for urine and serumpregnancy testing prior to enrollment and prior to vaccination. Pregnancy riskassessment and pregnancy prevention counseling will occur at each point of contact.

7. Willingness to refrain from blood donation during participation in the study and forat least 1 year after receiving the second dose of vaccine.

8. Willingness to refrain from receiving vaccines or other investigational productsduring the first 90 days of the study after enrollment.

Exclusion Criteria:

1. Pregnancy as determined by a positive human choriogonadotropin (ßHCG) test in aperson of reproductive capacity.

2. Currently breastfeeding.

3. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic,rheumatologic, autoimmune, or renal disease by history, physical examination,electrocardiogram (EKG), and/or laboratory studies.

4. Behavioral or cognitive impairment or psychiatric disease that in the opinion of theinvestigator affects the ability of the subject to understand and cooperate with thestudy protocol.

5. A history of asthma within the past 5 years, or a current diagnosis of asthma orreactive airway disease associated with exercise, seasonal hay fever or allergicrhinitis.

6. Presence of any febrile illness or symptoms suggestive of a respiratory infectionwithin 2 weeks prior to inoculation.

7. Use of systemic or nasal steroid preparations or immunosuppressive drugs within 30days prior to vaccination. Topical steroid preparations are permitted.

8. Inhaled bronchodilator or inhaled steroid use within the last year or use afterupper respiratory tract infections within the last 5 years.

9. Current or past (in the last 4 weeks) use of intranasal medications (includingsteroids, decongestants, or hormonal medications), or planning to use them within 28days of study vaccination.

10. Evidence of current alcohol or illicit drug abuse or addiction.

11. Other condition that in the opinion of the investigator would jeopardize the safetyor rights of a subject participating in the trial or would render the subject unableto comply with the protocol.

12. Positive ELISA and confirmatory tests for human immunodeficiency virus (HIV).

13. Positive ELISA and confirmatory test (e.g., recombinant immunoblot assay) forhepatitis C virus (HCV).

14. Positive hepatitis B virus surface antigen (HBsAg) by ELISA.

15. Known immunodeficiency syndrome.

16. Receipt of a live vaccine within 4 weeks or a killed vaccine within 2 weeks prior toreceipt of the study vaccine or planned receipt within 90 days after vaccination. (Exception, influenza vaccine may be obtained more than 2 weeks after or prior tothe study vaccine).

17. History of a surgical splenectomy.

18. Receipt of blood or blood-derived products (including immunoglobulin [Ig]) within 6months prior to study inoculation.

19. Has participated in another investigational study involving any investigationalproduct within 30 days, or 5 half-lives, whichever is longer, before the firstvaccine administration.

20. Body mass index (BMI) < 18.5 or >40.

21. Any significant abnormality of the nose or nasopharynx, including recurrentepistaxis and including nasal or sinus surgery.

22. History of Bell's palsy.

23. Has a confirmed SARS-CoV-2 infection or COVID-19 vaccine/booster within 16 weeksprior to enrollment.

24. Unwillingness to have nasopharyngeal (NP) or blood samples saved for futurerespiratory virus research.

25. Pulmonary function test (PFT) testing for FVC, FEV1, FEV1% and PEF of <80 orincentive spirometer value < normal parameters based on gender, age, and height.