ID93+GLA-SE, a freeze-dried tuberculosis vaccine, was confirmed to be safe in the first clinical study of any subunit TB vaccine in a temperature-stable form.
The effectiveness of a regimen in which non-thermostable ID93 and liquid GLA-SE are held in two vials and then blended before injection was compared to the administration of a temperature-stable vaccine that contained both ID93 and GLA-SE in a single vial.
Four proteins from the Mycobacterium tuberculosis bacteria are mixed with the immune-stimulating adjuvant GLA-SE to create the recombinant subunit vaccine. In the Phase I experiment, the vaccination triggered immune system cellular responses as well as antibodies.
The vaccine candidate had previously undergone several clinical trials using a non-temperature-stable version, according to the study’s authors.
The two-vial, non-thermostable regimen was given to 22 participants, while the thermostable single-vial regimen was given to 23 subjects. Both vaccine administration methods were secure and well-received. In comparison to those who received the non-thermostable two-vial presentation, recipients of the single-vial thermostable vaccine exhibited robust T-cell responses and produced higher levels of antibodies in the blood.
The freeze-dried formulation is combined with sterile water immediately before injection and does not need to be refrigerated. In environments where keeping vaccines cold or frozen for extended periods can be expensive and challenging, thermostable vaccines are preferred. A single-vial presentation of a vaccine might make it easier to store, transport, and administer, according to trial researchers.
No recognized correlates of protection have been identified that specify the immune responses necessary for vaccine-induced protection from TB, according to the investigators, who noted the trial’s small size. Because of this, it is impossible to predict whether the better immune responses reported in the thermostable vaccine formulation will result in an improved vaccination’s ability to provide protection. However, Sagawa et al. concluded that the results provided proof of concept that adjuvant-containing vaccines may be created in a freeze-dried single-vial presentation without negatively affecting clinical immunogenicity or safety characteristics.