Clinical study to evaluate safety, tolerability and effects on the immune system of a common cold vaccine in healthy adults

INTERVENTION: RSVdG Vaccine or placebo CONDITION: Prophylaxis, Infection, Respiratory Syncytial Virus (RSV) ; ; PRIMARY OUTCOME: Tolerability: Naso‐oropharyngeal pain during and shortly after administration (VAS); Safety: ; ; ‐ occurence in treatment‐emergent (S)AEs; ; ‐ occurrence and severity of solicited adverse events (local and systemic reactions); ; ‐ change in laboratory safety data, vital signs, body temperature SECONDARY OUTCOME: Viral load and shedding in nasal wash by CCID50 and PCR: presence and duration of presence of viral load ; Immunogenicity ; ; ‐ % of subjects with increase in virus neutralizing titers in serum or nasal wash ; ; ‐ mean fold‐increase in virus neutralizing titers ; ; ‐ Increase in RSV‐specific IgA in nasal wash and percentage of subjects with increase in IgA titers ; ; ‐ Palivizumab‐competing antibodies in serum ; INCLUSION CRITERIA: 1. Healthy male or female, 18‐50 years of age, inclusive at screening; 2. Body mass index (BMI) > 18.0 and < 32.0 kg/m2; 3. Good health, based upon the results of medical history, physical examination, vital signs, ECG, and laboratory profiles of both blood and urine; 4. Pre‐existing virus neutralization antibody titers (VNT) against RSV below 9.5 log2(titer) at screening; 5. Willing to comply with effective contraception during the study if subject is male or woman of child bearing potential, up to 90 days after the vaccine administration; 6. Signed informed consent prior to any study‐mandated procedure; 7. The ability to communicate well with the Investigator in the Dutch language 8. Willing to comply with the study restrictions.