Vaccine presentations and delivery technologies – what does the future hold?

Polymeric Nanoparticle-Based Vaccine Adjuvants and Delivery Vehicles

As vaccine formulations have progressed from including live or attenuated strains of pathogenic components for enhanced safety, developing new adjuvants to more effectively generate adaptive immune responses has become necessary. In this context, polymeric nanoparticles have emerged as a promising platform with multiple advantages, including the dual capability of adjuvant and delivery vehicle, administration via multiple routes, induction of rapid and long-lived immunity, greater shelf-life at elevated temperatures, and enhanced patient compliance. This comprehensive review describes advances in nanoparticle-based vaccines (i.e., nanovaccines) with a particular focus on polymeric particles as adjuvants and delivery vehicles. Examples of the nanovaccine approach in respiratory infections, biodefense, and cancer are discussed.

A Study of Methods to Identify Industry-University-Research Institution Cooperation Partners based on Innovation Chain Theory

Purpose

This study aims at identifying potential industry-university-research collaboration (IURC) partners effectively and analyzes the conditions and dynamics in the IURC process based on innovation chain theory.

Design/methodology/approach

The method utilizes multisource data, combining bibliometric and econometrics analyses to capture the core network of the existing collaboration networks and institution competitiveness in the innovation chain. Furthermore, a new identification method is constructed that takes into account the law of scientific research cooperation and economic factors.

Findings

Empirical analysis of the genetic engineering vaccine field shows that through the distribution characteristics of creative technologies from different institutions, the analysis based on the innovation chain can identify the more complementary capacities among organizations.

Research limitations

In this study, the overall approach is shaped by the theoretical concept of an innovation chain, a linear innovation model with specific types or stages of innovation activities in each phase of the chain, and may, thus, overlook important feedback mechanisms in the innovation process.

Practical implications

Industry-university-research institution collaborations are extremely important in promoting the dissemination of innovative knowledge, enhancing the quality of innovation products, and facilitating the transformation of scientific achievements.

Originality/value

Compared to previous studies, this study emulates the real conditions of IURC. Thus, the rule of technological innovation can be better revealed, the potential partners of IURC can be identified more readily, and the conclusion has more value.

Can a Compact Pre-Filled Auto-Disable Injection System (cPAD) Save Costs for DTP-HepB-Hib Vaccine as Compared with Single-Dose (SDV) and Multi-Dose Vials (MDV)? Evidence from Cambodia, Ghana, and Peru

Background

A compact pre-filled auto-disable injection (cPAD) presentation is being developed for the fully liquid pentavalent DTP-HepB-Hib vaccine. A cost analysis (CA) to compare this presentation with the presently used single-dose vial (SDV) and multi-dose vial (MDV) was conducted in Cambodia, Ghana, and Peru.

Methodology

The CA included the development of an excel-based costing model and considered the costs of vaccine, safe injection equipment, procurement, storage, transport and distribution, vaccine administration by health staff, medical waste management, start-up activities, as well as coverage, birth cohort, vaccine, and safe injection equipment wastage rates. The outcome was the change in cost per pentavalent fully immunized child (PFIC) for a switch to cPAD. Field visits to health facilities, and interviews with key informants from immunization services and regulatory authorities, were conducted to collect data and to test the costing model in country context. Cost data were also obtained from manufacturers, published price lists, and author estimates. A sensitivity analysis (SA) was conducted to explore possible variations in values of data collected.

Results

Based on vaccine price trends estimated for 2016, cPAD is less costly in Ghana [incremental cost per PFIC: $US−0.59 (−6.46 %)] than the current presentation (ten-dose MDV) and in Peru (SDV): $US−0.89 (−7.14 %). In Cambodia, cPAD is more costly than SDV: $US+0.33 (+3.90 %).

Discussion and Conclusion

The most significant cost item per PFIC is the vaccine (reflecting wastage rates) in all presentations. The dominance of the vaccine price per dose and, to a lesser extent, the wastage rates in the incremental cost per PFIC show potential to simplify future analyses. Other relevant considerations at country level for a change of presentation include the potential for improved safety with cPAD, planned introduction of other vaccines, environmental and safety issues, and financial sustainability.

Electronic supplementary material

The online version of this article (doi:10.1007/s40801-015-0010-0) contains supplementary material, which is available to authorized users.

Children who received PCV-10 vaccine from a two-dose vial without preservative are not more likely to develop injection site abscess compared with those who received pentavalent (DPT-HepB-Hib) vaccine: a longitudinal multi-site study

BACKGROUND

The single dose pneumonia ten-valent vaccine has been widely used and is highly efficacious against selected strains Streptococcus pneumonia. A two-dose vial without preservative is being introduced in developing countries to reduce the cost of the vaccine. In routine settings improper immunization practice could result in microbial contamination leading to adverse events following immunization.

OBJECTIVE

To monitor adverse events following immunization recommended for routine administration during infancy by comparing the rate of injection-site abscess between children who received PCV-10 vaccine and children who received the Pentavalent (DPT-HepB-Hib) vaccine.

METHODS

A longitudinal population-based multi-site observational study was conducted between September 2011 and October 2012. The study was conducted in four existing Health and Demographic Surveillance sites run by public universities of Abraminch, Haramaya, Gondar and Mekelle. Adverse events following Immunization were monitored by trained data collectors. Children were identified at the time of vaccination and followed at home at 48 hour and 7 day following immunization. Incidence of abscess and relative risk with the corresponding 95% Confidence Intervals were calculated to examine the risk difference in the comparison groups.

RESULTS

A total of 55, 268 PCV and 37, 480 Pentavalent (DPT-HepB-Hib) vaccinations were observed. A total of 19 adverse events following immunization, 10 abscesses and 9 deaths, were observed during the one year study period. The risk of developing abscess was not statistically different between children who received PCV-10 vaccine and those received Pentavalent (RR = 2.7, 95% CI 0.576-12.770), and between children who received the first aliquot of PCV and those received the second aliquot of PCV (RR = 1.72, 95% CI 0.485-6.091).

CONCLUSION

No significant increase in the risk of injection site abscess was observed between the injection sites of PCV-10 vaccine from a two-dose vial without preservative and pentavalent (DPT-HepB-Hib) vaccine in the first 7 days following vaccination.

Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model

Background

Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks.

Methods

We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes.

Results

Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively.

Conclusions

The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.

Clarification of how HIV-1 DNA and protein immunizations may be better used to obtain HIV-1-specific mucosal and systemic immunity

More focused research on a mucosal HIV-1 vaccine is needed urgently. An increasing amount of collected data, using heterologous multimodality prime-booster strategies, suggest that an efficient and protective HIV-1 vaccine must generate broad, long-lasting HIV-specific CD8(+) cytotoxic T-lymphocyte and neutralizing antibody responses. In the mucosa, these responses would be most effective if a preferential stimulus of HIV-1 neutralizing secretory immunoglobulin A and G were obtained. The attractive property of mucosal immunization is the obtained mucosal and systemic immunity, whereas systemic immunization induces a more limited immunity, predominantly in systemic sites. These objectives will require new vaccine regimens, such as multiclade HIV DNA and protein vaccines (nef, tat, gag and env expressed in DNA plasmids) delivered onto mucosal surfaces with needle-free delivery methods, such as nasal drop, as well as oral and rectal/vaginal delivery, and should merit clinical trials.

A vaccine cold chain freezing study in PNG highlights technology needs for hot climate countries

Fourteen data loggers were packed with vaccine vials at the national vaccine store, Port Moresby, Papua New Guinea (PNG), and sent to peripheral locations in the health system. The temperatures that the data loggers recorded during their passage along the cold chain indicated that heat damage was unlikely, but that all vials were exposed to freezing temperatures at some time. The commonest place where freezing conditions existed was during transport. The freezing conditions were likely induced by packing the vials too close to the ice packs that were themselves too cold, and with insufficient insulation between them. This situation was rectified and a repeat dispatch of data loggers demonstrated that the system had indeed been rectified. Avoiding freeze damage becomes even more important as the price of freeze-sensitive vaccines increases with the introduction of more multiple-antigen vaccines. This low-cost high-tech method of evaluating the cold chain function is highly recommended for developing and industrialized nations and should be used on a regular basis to check the integrity of the vaccine cold chain. The study highlights the need for technological solutions to avoid vaccine freezing, particularly in hot climate countries.

When science is not enough – a risk/benefit profile of thiomersal-containing vaccines

Without a preservative, such as thiomersal (known as thimerosal in the US), multi-dose liquid presentations of vaccine are vulnerable to bacteriological contamination that can result in death or serious illness of the recipient. Concerns about levels of mercury exposure from thiomersal-containing vaccines were first raised in the US during 1999 in the context of Hepatitis B vaccine for newborns. Since then, a large body of evidence from animal and epidemiological studies has accumulated on the safety of thiomersal. Ironically, these data have become largely irrelevant in wealthy countries, where mono-dose, thiomersal-free vaccines have been introduced as a precautionary measure in almost all childhood vaccines, in part related to residual public scepticism. In poor countries, multi-dose vials remain important for vaccine delivery. There is a real danger that this controversy may result in the loss to the world of thiomersal as a preservative, simply from popular pressure. In reality, it would be impossible to cease overnight using thiomersal and maintain the supply of vital vaccines. This paper reviews and summarises the data available from published studies on mercury toxicity, and thiomersal in vaccines in particular, that overwhelmingly indicate continued use of thiomersal is safe in those countries where it is most needed.