Single-ascending-dose Study of the Safety and Immunogenicity of NasoVAX

∙ Subjects who meet all of the following criteria may be included in the study:

• Men and women 18 to 49 years of age, inclusive

• Good general health status as determined by the Investigator

• Adequate venous access for repeated phlebotomies

• Screening laboratory results within institutional normal range or Grade 1 elevation if the Investigator documents clinical insignificance. Creatine kinase or bilirubin may be Grade 2 if associated with normal alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the Investigator considers the result not to be clinically significant due to vigorous exercise or Gilbert's syndrome

• Negative drug and alcohol screen at Screening and predose on Day 1

• For women who have not been surgically sterilized or have laboratory confirmation of postmenopausal status, negative pregnancy test

• Willingness to practice a highly effective method of contraception that may include, but is not limited to, abstinence, sex only with persons of the same sex, monogamous relationship with a postmenopausal partner, monogamous relationship with vasectomized partner, vasectomy, surgical sterilization (hysterectomy, or bilateral tubal ligation, salpingectomy, or oophorectomy), licensed hormonal methods, intrauterine device (IUD), or consistent use of a barrier method (eg, condom, diaphragm) with spermicide for 28 days after the NasoVAX/placebo dose

• Willingness to participate and comply with all aspects of the study through the entire study period, including nasopharyngeal swabs and blood and urine samples

• Provision of written informed consent

∙ Subjects who meet any of the following criteria will be excluded from the study:

• Pregnant, possibly pregnant, or lactating women

• Household contacts of pregnant women, children \< 5 years of age, or immunocompromised individuals for the period up through 2 weeks postvaccination

• Persons who care for pregnant women, children \< 5 years of age, or immunocompromised individuals for the period up through 2 weeks postvaccination

• Body mass index \> 35.0 kg/m2

• Positive results for HIV, hepatitis B virus, or hepatitis C virus at Screening

• Asthma or other chronic lung disease that is greater than mild in severity. Specifically excluded are participants with the any of the following events in the past year:

‣ Daily symptoms

⁃ Daily use of short acting beta 2 agonists

⁃ Use of inhaled steroids or theophylline

⁃ Use of pulse systemic steroids

⁃ Emergency care or hospitalization related to asthma or other chronic lung disease

⁃ Systemic steroids for asthma exacerbation

• History of diabetes mellitus (gestational diabetes is allowed if treatment was not required postpartum and serum glucose is currently in the normal range)

• History of coronary artery disease, arrhythmia, or congestive heart failure

• Clinically significant ECG abnormality as determined by the Investigator

⁃ Poorly controlled hypertension (systolic blood pressure \> 150 mmHg or diastolic blood pressure \> 95 mmHg) at Screening or predose on Day 1

⁃ History of anaphylaxis or angioedema

⁃ Known allergy to any of the ingredients in the vaccine formulation

⁃ History of chronic rhinitis, nasal septal defect, cleft palate, nasal polyps, or other nasal abnormality that might affect vaccine administration

⁃ Previous nasal surgery or nasal cauterization

⁃ Any symptoms of upper respiratory infection or temperature \> 38°C within 3 days before Day 1

⁃ Any symptoms within 24 hours before Day 1 of upper respiratory illness of allergy flare-up that, in the opinion of the Investigator, presents as nasal congestion or rhinorrhea that could inhibit the proper administration of the IP

⁃ Known or suspected malignancy, excluding non-melanoma skin cancers and other early stage surgically excised malignancies that the Investigator considers to be exceedingly unlikely to recur

⁃ Immunocompromised individuals, including those who have used corticosteroids (including intranasal steroids), alkylating drugs, antimetabolites, radiation, immune-modulating biologics, or other immunomodulating therapies within 90 days before Day 1 or those who plan use during the study period

⁃ Use of statin medication within 30 days before Day 1 (see list in Section 6.8.1)

⁃ Receipt of intranasal medications (including over-the-counter medications) within 30 days before Day 1

⁃ Receipt of any investigational product (IP) within 30 days before Day 1

⁃ Receipt of any vaccine within 30 days before Day 1

⁃ Receipt of intranasal vaccine within 90 days before Day 1

⁃ Receipt of any influenza vaccine within 6 months before Day 1

⁃ Any change in medication for a chronic medical condition within 30 days before Day 1

⁃ Past regular use or current use of intranasal illicit drugs

⁃ Smoking of any type (eg, cigarettes, electronic cigarettes, marijuana) or use of any tobacco product within 30 days before Day 1

⁃ Any medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the Investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety (including reactogenicity), or a subject's ability to give informed consent