PCPP-Formulated H5N1 Influenza Vaccine Displays Improved Stability and Dose-Sparing Effect in Lethal Challenge Studies

The effect of stable macromolecular complexes of ionic polyphosphazene on HIV Gag antigen and on activation of human dendritic cells and presentation to T-cells

“…Although more studies need to be conducted to investigate functional stability of the antigen in the formulations, the results clearly show that the addition of PCPP and the formation of macromolecular complexes with Gag alleviate undesirable molecular changes thereby promoting antigen stability. These results are also in line with previous findings on the protein stabilizing effect of PCPP in aqueous solutions [5,13].…”

“…Instead, polyphosphazenes are thought to engage in noncovalent interactions with antigens to form water-soluble multimeric complexes [11] with resulting in vivo complex activity depending on molecular weight, the amount of antigen bound (protein loading), and the degree of complex compaction (effective antigen presentation). Finally, PCPP can enhance thermal stability of vaccine antigens [5,13], a critical requirement for many successful vaccine formulations [14,15] that may improve vaccine shelf life and reduce dependence of their distribution and storage on cold-chain facilities [16,17].…”

Potential of Nanocarriers in Antigen Delivery: The Path to Successful Vaccine Delivery

“…The nanoparticles were shown to present stability would be a boon for vaccine stocking in case of pandemic episodes and it would decrease the dependence on costly cold chain facilities for storage and distribution. PCPP resulted in a four-fold higher half life of the vaccine at 40 o C. Also, IM immunization of the PCPP adjuvanted vaccine conferred 100% protection in ferrets at a 10-fold lower antigen dose than the non-adjuvanted vaccine [102]. Andrianov et al also have formulated microneedles for ID immunization using PCPP.…”

“…Polyphosphazene forms noncovalent complexes with antigens resulting in improved stability of antigen and multimeric antigen presentation [101]. PCPP adjuvanted vaccines have been evaluated in clinical trials where they were shown to be safe and efficacious [102]. An aqueous formulation of PCPP when used in combination with influenza antigens showed 10-fold higher antibody levels than plain influenza antigen.…”

Current and next generation influenza vaccines: Formulation and production strategies

“…Ideally, an influenza vaccine would protect against all 141 strains, uninfluenced by antigenic changes. VN titers indicate anti- 142 body responses that are able to neutralize influenza virus, and thus 143 can potentially be applied for cross-reactive vaccines. Nonetheless, 144 identification of alternative CoPs, such as cross-reactive antibodies 145 or T cell responses would significantly aid the development of uni- adults and the elderly [27], but lower efficacy rates in children [28].…”