Table 2 Summary of major pre-clinical trial studies of aerosol measles vaccines presented to the expert group for stage II of the CHNRI process
Reference | Factor for investigation | Results | Comment |
|---|---|---|---|
Low, N et al | Vaccine strain | EZ > Schwarz in all studies. | In South Africa, the Schwarz strain was inactivated as an aerosol. |
Laube, B.L [26] | Device selection | 3 systems for entry at clinical trial: Un-vented, Breath-enhanced & Ultrasonic nebulizer. All models fulfil safety and logistic criteria. | Suitability criteria – portable, easy to use, battery-operated, sanitary, operable with replacement parts. |
Coates, A.L et al[52] | Viral particle size | Minimum < 10μm Deep lung deposition <5μm | Size of inhaled droplet is best determinant of lung deposition |
Coates, A.L et al[52] | Number of infective particles | <1000 pfu’s; 30-250 pfu’s required to stimulate immune response | 5000 pfu’s delivered in percutaneous measles vaccine |
Cohen, B.J et al[53] | Potency retention | 85-102% vaccine potency retention in all 3 measles aerosol device’s. | Potential disaggregation of viral particles during aerosolization accounts for results >100% |
de Swart, R. L et al [54] | Animal model – safety | No superimposed risk in immunocompromised or asthmatics. No risk of vaccine-associated encephalitis or Bells palsy identified. | Concern of illness exacerbation in vulnerable groups. Postulation of direct CNS contact through cribiform plate precipitating neurological symptoms. |