Implementing public health nursing training for Ireland's National Healthy Childhood Programme.

Public health nurses (PHNs) in Ireland provide preventative child health. An evidence-based National Healthy Childhood Program (NHCP) has been in development since 2016. The final program implementation, including training all PHNs coincided with the Covid-19 pandemic. OBJECTIVE: To describe implementation and evaluation of a blended training program for PHNs DESIGN: The evaluation used quantitative and qualitative methods underpinned by an implementation science framework to assess the training program. The three-phase blended training was led by a Training and Resources implementation team. Data from a national cohort of PHNs (n = 1671) who completed training were descriptively analysed. RESULTS: The majority of PHNs completed a suite of four online units (phase 1), as well as self-directed and asynchronous content in phase 2. Results of phase 2 indicated it met participant needs in terms of knowledge but outstanding needs in terms of skills remained. Phase 3 (a modified Face to Face Clinical Skills Review) was completed by 1671 PHNs over a 5-month period in 2020. Evaluation was very positive in terms of organisation and usefulness for practice. CONCLUSIONS: Despite challenges the NHCP training implementation goals were met. A well-designed blended learning training program met service delivery imperatives and PHN needs.

The 'co-delivery' approach to liposomal vaccines: application to the development of influenza-A and hepatitis-B vaccine candidates.

DNA vaccination with mammalian-expressible plasmid DNA encoding protein antigens is known to be an effective means to elicit cell-mediated immunity, sometimes in the absence of a significant antibody response. This may be contrasted with protein vaccination, which gives rise to antibody responses with little evidence of cell-mediated immunity. This has led to considerable interest in DNA vaccination as a means to elicit cell-mediated immune responses against conserved viral antigens or intracellular cancer antigens, for the purpose of therapeutic vaccination. However, almost all current vaccines are used prophylactically and work by producing antibodies rather than cell mediated immune responses. In the present study we have therefore explored the combination of DNA and protein forms of an antigen using two exemplary prophylactic vaccine antigens, namely inactivated influenza virion and hepatitis-B surface antigen. We studied the effects of various combinations of DNA and protein on the antibody response. Co-administration of soluble forms of DNA and protein representations of the same antigen gave rise to the same level of antibody response as if protein were administered alone. In contrast, we found that when these antigens are entrapped in the same liposomal compartment, that there was a strong synergistic effect on the immune response, which was much greater than when either antigen was administered alone, or in various other modes of combination (e.g. co-administration as free entities, also pooled liposomal formulations where the two materials were contained in separate liposomal vehicles in the same suspension). The synergistic effect of liposomally co-entrapped DNA and protein exceeded, markedly, the well known adjuvant effects of plasmid DNA and liposomes. We have termed this new approach to vaccination 'co-delivery' and suggest that it may derive from the simultaneous presentation of antigen via MHC class-I (DNA) and MHC class-II (protein) pathways to CD8+ and CD4+ cells at the same antigen presenting cell--a mode of presentation that would commonly occur with live viral pathogens. We conclude that co-delivery is a very effective means to generate protective antibody responses against viral pathogens.

Polysialylated insulin: synthesis, characterization and biological activity in vivo.

Polysialic acids (PSA) (colominic acid; CA) of 22 and 39 kDa average molecular weight were oxidized with sodium periodate at carbon 7 of the nonreducing end to form an aldehyde group. The oxidized CAs (96-99% oxidation) were then reacted with the amino groups of recombinant human insulin at various CA/insulin molar ratios (25:1 to 150:1 range) for up to 48 h in the presence of sodium cyanoborohydride (reductive amination). Polysialylated insulin conjugates were precipitated (together with intact nonreacted insulin, if any) at time intervals from the reaction mixtures with ammonium sulfate, further purified by size exclusion chromatography and/or ion exchange chromatography (IEC), and the final conjugates assayed for PSA and protein. Results showed an initial rapid conjugation rate peaking at about 12 h, to form a plateau over a period of 12-48 h. Moreover, the extent of polysialylation (CA/insulin molar ratios in the conjugate) was dependent on the PSA used, the initial CA/insulin molar ratios in the reaction mixture and the time of the coupling reaction. Thus at 48 h of incubation, CA/insulin molar ratios in the conjugates were 1.60-1.74 for the 22-kDa CA and 2.37-2.45 for the 39-kDa CA. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of intact insulin and insulin reacted with non-oxidized CA for 48 h revealed well-resolved single bands which migrated similar distances in the gel. On the other hand, polysialylated (22-kDa CA) insulin yielded multiple diffused bands suggesting heterogenicity as a result of differential polysialylation. The pharmacological activity of polysialylated insulin was compared with that of intact insulin in normal female outbred T/O mice. After subcutaneous injection of intact insulin (0.3 units per mouse), blood glucose levels were reduced to nadir values at 1 h to return to normal at 3 h. In contrast, blood glucose levels in animals injected with polysialylated insulin (0.3 units or protein equivalence for polysialylated insulin), having attained nadir values also at 1 h, returned to normal levels after 6 h (39 kDa) and 9 h (22 kDa CA-insulin). It is concluded that polysialylation offers a promising strategy for the enhancement of the therapeutic value of insulin and other pharmacologically active peptides.

A role for liposomes in genetic vaccination.

Genetic immunization by the use of plasmid DNA encoding antigens from bacteria, viruses, protozoa and cancers has often led to protective humoral and cell-mediated immunity, and has some practical advantages over conventional vaccines. However, naked DNA vaccines can be degraded by nucleases in situ, are unable to target antigen presenting cells (APCs), and exhibit poor performance when administered by routes other than the intramuscular, all of which have reduced the value of the approach. We have been able to avoid DNA degradation and also target DNA to APCs by the use of liposomes as DNA vaccine carriers. Entrapment of plasmid DNA within the aqueous spaces of cationic liposomes is effected by a one step procedure which results in most of the DNA being incorporated into a freeze dried, ready to use preparation. Animal experiments have shown that immunization by the intramuscular or the subcutaneous route with liposome-entrapped plasmid DNA encoding the hepatitis B surface antigen leads to much greater humoral (IgG subclasses) and cell mediated (splenic IFN-gamma) immune responses than with naked DNA. In other experiments with a plasmid DNA encoding a model antigen (ovalbumin), a cytotoxic T lymphocyte (CTL) response was also observed. These results could be explained by the ability of liposomes to protect their DNA content from local nucleases and direct it to APCs in the lymph nodes draining the injected site.