By contrast, aggregates in the freeze-damaged samples measured up to 700 μ m (diphtheria-tetanus-pertussis) and 350 μ m on average.ĬONCLUSION: The shake test had 100% sensitivity, 100% specificity and 100% positive predictive value in this study, which confirms its validity for detecting freeze damage to aluminium-based freeze-sensitive vaccines. Particles in the non-frozen samples measured from 1 μ m (vaccines against diphtheria-tetanus-pertussis Haemophilus influenzae type b hepatitis B diphtheria-tetanus-pertussis-hepatitis B) to 20 μ m (diphtheria and tetanus vaccines, alone or in combination). Non-frozen samples showed a fine-grain structure under phase contrast microscopy, but freeze-damaged samples showed large conglomerates of massed precipitates with amorphous, crystalline, solid and needle-like structures. Selected numbers of vials from each type were then exposed to '25 ☌ and '2 ☌ for 24-hour periods.įINDINGS: There was complete concordance between HCWs and phase-contrast microscopy in identifying freeze-damaged vials and non-frozen samples. A total of 475 vials of 8 different types of World Health Organization prequalified freeze-sensitive vaccines from 10 different manufacturers were used. METHODS: A double-blind crossover design was used to compare the performance of the shake test conducted by trained health-care workers (HCWs) with that of phase contrast microscopy as a 'gold standard'.

OBJECTIVE: To determine the validity of the shake test for detecting freeze damage in aluminium-based, adsorbed, freeze-sensitive vaccines. IVNational Institute of Hygiene, Warsaw, Poland IIIGlobal Influenza Programme, World Health Organization, Geneva, Switzerland IIEmergency Department, Karaman Hayat Medical Centre, Karaman, Turkey IDepartment of Immunization, Vaccines and Biologicals, World Health Organization, 20 Avenue Appia, 27 Geneva 1211 Switzerland

Ümit Kartoglu I, * Nejat Kenan Özgüler II Lara J Wolfson III Wiesław Kurzatkowski IV

Validación de la prueba de agitación para detectar daños por congelación en las vacunas adsorbidas Validation de l'épreuve d'agitation pour la détection des dommages occasionnés aux vaccins adsorbés Validation of the shake test for detecting freeze damage to adsorbed vaccines

Microscopia de contraste de fases