Urea Improves Stability of Inactivated Polio Vaccine Serotype 3 During Lyophilization and Storage in Dried Formulations

Stable formulations of inactivated polio vaccine (IPV) could reduce cold-chain requirements and increase distribution of the vaccine to developing countries. Recently, significant improvement in thermal stability of IPV vaccines has been achieved by including urea in lyophilized formulations. In the present study, we investigated the effects of urea on recovery of potency of IPV after lyophilization and storage at 37°C and the correlation of potency recovery with key biophysical properties of IPV. By dynamic light scattering and transmission light microscopy, we found that loss of potency appeared to be due to agglomeration of virus particles during lyophilization and that moderate concentrations (e.g., 0.4 M) of urea reduced agglomeration and improved potency recovery. In addition, the relative thermal stability of the viron proteins was assessed after rehydration with temperature-dependent intrinsic fluorescence. Lyophilization of formulations without urea and postdrying storage resulted in reduced apparent melting temperatures in rehydrated samples. In formulations with urea, the rehydrated samples had thermal transitions and melting temperatures that were similar to those observed in aqueous control samples. Overall, the results indicated that in IPV formulations, urea improved potency recovery by inhibiting viron particle agglomeration and reducing denaturation of viron proteins.     

Development of Thermostable Lyophilized Inactivated Polio Vaccine

Purpose

The aim of current study was to develop a dried inactivated polio vaccine (IPV) formulation with minimal loss during the drying process and improved stability when compared with the conventional liquid IPV.

Methods

Extensive excipient screening was combined with the use of a Design of Experiment (DoE) approach in order to achieve optimal results with high probability.

Results

Although it was shown earlier that the lyophilization of a trivalent IPV while conserving its antigenicity is challenging, we were able to develop a formulation that showed minimal loss of potency during drying and subsequent storage at higher temperatures.

Conclusion

This study showed the potential of a highly stable and safe lyophilized polio vaccine, which might be used in developing countries without the need of a cold-chain.     

Determination of Depth-Dependent Intradermal Immunogenicity of Adjuvanted Inactivated Polio Vaccine Delivered by Microinjections via Hollow Microneedles

Purpose

The aim of this study was to investigate the depth-dependent intradermal immunogenicity of inactivated polio vaccine (IPV) delivered by depth-controlled microinjections via hollow microneedles (HMN) and to investigate antibody response enhancing effects of IPV immunization adjuvanted with CpG oligodeoxynucleotide 1826 (CpG) or cholera toxin (CT).

Methods

A novel applicator for HMN was designed to permit depth- and volume-controlled microinjections. The applicator was used to immunize rats intradermally with monovalent IPV serotype 1 (IPV1) at injection depths ranging from 50 to 550 μm, or at 400 μm for CpG and CT adjuvanted immunization, which were compared to intramuscular immunization.

Results

The applicator allowed accurate microinjections into rat skin at predetermined injection depths (50–900 μm), -volumes (1–100 μL) and -rates (up to 60 μL/min) with minimal volume loss (±1–2%). HMN-mediated intradermal immunization resulted in similar IgG and virus-neutralizing antibody titers as conventional intramuscular immunization. No differences in IgG titers were observed as function of injection depth, however IgG titers were significantly increased in the CpG and CT adjuvanted groups (7-fold).

Conclusion

Intradermal immunogenicity of IPV1 was not affected by injection depth. CpG and CT were potent adjuvants for both intradermal and intramuscular immunization, allowing effective vaccination upon a minimally-invasive single intradermal microinjection by HMN.

     

高效液相色谱法测定流感病毒裂解疫苗中Triton X-100的含量

目的:建立流感病毒裂解疫苗中裂解剂Triton X-100含量的HPLC法。方法:采用SymmetryShieldTM RP18色谱柱(4.6 mm×250 mm,5μm),以注射用水-无水甲醇(20∶80)为流动相,流速为1.5 mL.min-1,柱温为25℃,检测波长为230nm,进样量为10μL,用面积归一法测定。结果:Triton X-100在625～39μg.mL-1范围内线性关系良好(r=0.9994),流感病毒裂解疫苗原液平均加样回收率为107.7%,RSD为0.3%;流感病毒裂解疫苗平均加样回收率为108.5%,RSD为0.4%。结论:本方法灵敏度高,操作简便可靠。     

Physicochemical Characterization of Sabin Inactivated Poliovirus Vaccine for Process Development

Upscaling the production capacity of inactivated poliovirus vaccines (IPV) is urgently needed to eradicate polio worldwide. For the development of a robust manufacturing process for IPV, the impact of stresses on the properties of the poliovirus during manufacturing needs to be carefully evaluated. In this study, the physicochemical properties of Sabin poliovirus after low pH exposure were analyzed by asymmetrical flow field-flow fractionation coupled to multi-angle laser light scattering (AF4-MALS), sedimentation velocity analytical ultracentrifugation (SV-AUC), transmission electron microscopy (TEM), dynamic light scattering (DLS) and surface plasmon resonance (SPR). Low pH stress caused structural changes and aggregation of inactivated poliovirus virions, whereas degraded virion particles would not revert to native virions even after neutralization. Importantly, a complete loss of the D-antigenicity of IPV by low pH stress, followed by neutralization, was observed in SPR. These results suggest that the exposure of poliovirus particle to low pH stress would induce irreversible denaturation and aggregation of virus particles and lead to the loss of D-antigenicity; thus, low pH stress during the manufacturing of poliovirus vaccine should be minimized. The analytical methods above can be efficiently utilized in the development of high-integrity manufacturing processes and high-quality vaccines.     

Novel Hollow Microneedle Technology for Depth-Controlled Microinjection-Mediated Dermal Vaccination: A Study with Polio Vaccine in Rats

Purpose

The aim of the study was to develop a cheap and fast method to produce hollow microneedles and an applicator for injecting vaccines into the skin at a pre-defined depth and test the applicability of the system for dermal polio vaccination.

Methods

Hollow microneedles were produced by hydrofluoric acid etching of fused silica capillaries. An electromagnetic applicator was developed to control the insertion speed (1–3 m/s), depth (0–1,000 μm), and angle (10°–90°). Hollow microneedles with an inner diameter of 20 μm were evaluated in ex vivo human skin and subsequently used to immunize rats with inactivated poliovirus vaccine (IPV) by an intradermal microinjection of 9 μL at a depth of 300 μm and an insertion speed of 1 m/s. Rat sera were tested for IPV-specific IgG and virus-neutralizing antibodies.

Results

Microneedles produced from fused silica capillaries were successfully inserted into the skin to a chosen depth, without clogging or breakage of the needles. Intradermal microinjection of IPV induced immune responses comparable to those elicited by conventional intramuscular immunization.

Conclusions

We successfully developed a hollow microneedle technology for dermal vaccination that enables fundamental research on factors, such as insertion depth and volume, and insertion angle, on the immune response.     

肾综合征出血热灭活疫苗流行病学效果观察

应用中国预防医学科学院流行病学微生物学研究所出血热室研制生产的HFRS病毒鸡胚细胞灭活疫苗，连续2年在贵州省HFRS高发病区的遵义县进行了较大范围的人群免疫接种，并对其效果进行了观察。疫苗经1992年40966人初次免疫和1993年32556人加强免疫，除注射时先后有5人出现景厥、注射后少数人出现低热、注射部位短时轻微疼痛外，未见其他不适反应，说明疫苗的安全性是可靠的。初次免疫后血清NT抗体阳转率40．54％，加强免疫后血清NT抗体阳性率达75％以上，提示疫苗的免疫原性值得肯定。在疫苗免疫后的第1个观察年度内，疫苗组发病率9．76／10万，较对照组57．77／10万明显偏低（X2＝15．5，P＜0．01），保护率为83．11％；1年后加强免疫人群发病率9．21／10万，亦明显低于对照组发病率188．22／10万（X2＝53．88，P＜0．01），保护率达95．10％，疫苗起到了较好的保护作用，具有明显的流行病学效果。研究结果表明，该疫苗是安全的，可以较好地诱导机体产生NT抗体，有良好的流行病学效果，能有效地控制HFRS的流行。     

Enhanced Stability of Inactivated Influenza Vaccine Encapsulated in Dissolving Microneedle Patches

Purpose

This study tested the hypothesis that encapsulation of influenza vaccine in microneedle patches increases vaccine stability during storage at elevated temperature.

Methods

Whole inactivated influenza virus vaccine (A/Puerto Rico/8/34) was formulated into dissolving microneedle patches and vaccine stability was evaluated by in vitro and in vivo assays of antigenicity and immunogenicity after storage for up to 3 months at 4, 25, 37 and 45°C.

Results

While liquid vaccine completely lost potency as determined by hemagglutination (HA) activity within 1–2 weeks outside of refrigeration, vaccine in microneedle patches lost 40–50% HA activity during or shortly after fabrication, but then had no significant additional loss of activity over 3 months of storage, independent of temperature. This level of stability required reduced humidity by packaging with desiccant, but was not affected by presence of oxygen. This finding was consistent with additional stability assays, including antigenicity of the vaccine measured by ELISA, virus particle morphological structure captured by transmission electron microscopy and protective immune responses by immunization of mice in vivo.

Conclusions

These data show that inactivated influenza vaccine encapsulated in dissolving microneedle patches has enhanced stability during extended storage at elevated temperatures.

     

人用狂犬病灭活疫苗的临床研究和应用

狂犬病疫苗是预防狂犬病的安全有效方法。本文从人二倍体细胞疫苗、纯化Vero细胞狂犬病疫苗、层析纯化狂犬病疫苗的临床研究角度,概述此类广泛应用的人用狂犬病疫苗的优缺点、国内外的发展过程和临床免疫效果,以及我国当前对氢氧化铝佐剂疫苗和无佐剂疫苗的临床研究热点。数据显示国产无佐剂疫苗引起的不良反应发生率和抗体阳转率与进口同类疫苗相近,这类疫苗预防狂犬病的免疫效果是有保证的。     

Vero细胞肠道病毒71型灭活疫苗的纯化及鉴定

目的建立Vero细胞肠道病毒71型(EV71)灭活疫苗的纯化工艺。方法病毒收获液经离心澄清、福尔马林灭活和超滤浓缩后,采用Sephacryl S-400 HR凝胶过滤层析和Source 30Q离子交换层析2步层析法纯化EV71,进行各项检定及分析后除菌过滤。结果经纯化的疫苗各项纯化指标均符合中国药典2010年版的要求,杂蛋白去除率>99.9%;病毒纯化液在电镜下观察到典型的EV71病毒颗粒,经SDS-PAGE及Western blot分析,检测到与文献报道大小相符的EV71 VP1、VP2、VP3及特异性免疫反应;制备成疫苗后免疫大鼠能产生特异性中和抗体。结论本实验建立了Vero细胞的EV71灭活疫苗的纯化工艺,纯化后制备的EV71灭活疫苗具有较好的免疫原性。     

Safety and Immunogenicity of a High–Potency Inactivated Hepatitis A Vaccine

Background: In recent years, several hepatitis A vaccines have been developed. We wished to evaluate the safety, reactogenicity, and immunogenicity of an inactivated hepatitis A vaccine, containing 1440 EI.U., and to monitor the kinetics of the antibodies monthly for the first year after administration of a single dose of vaccine.
Methods: We conducted an open clinical trial, started in March 1992 and completed in July 1993, at two general hospitals and one pediatric hospital in Antwerp, Belgium, with 194 healthy adult healthcare volunteers. Each volunteer received a single dose hepatitis A vaccine, given intramuscularly at month 0 and a booster at month 12. We undertook serologic follow-up of antihepatitis A virus (antiHAV) antibodies and liver enzymes at day 15 and at months 1, 6, 9, 12, and 13. For a random subgroup of participants, blood samples were taken monthly. In addition, all participants noted local and general symptoms following administration of the vaccine.
Results: This single dose vaccine was well-tolerated; 2 weeks after the vaccination, 80% of the participants had seroconverted (antiHAV antibodies ≥ 20 mlU/mL); after 1 month, seroconversion reached 99% (geometric mean titer (GMT): 383 mlU/mL). One year after the single dose of vaccine, 94% still had antiHAV antibodies above 20 mlU/mL (GMT: 176 mlU/mL). One month afterthe booster dose, seroconversion was 100%, and GMT increased from 176 mlU/mL at month 12 to 4775 mlU/mL at month 13.
Conclusions: The single dose hepatitis A vaccine is safe and highly immunogenic; it gives a rapid antibody production and a rapid increase of GMT. The persistence of protective antibodies until month 12 allows a booster at month 12. This schedule will easily fit into existing travel or occupational health vaccination schedules and will improve vaccination compliance.     

反相高效液相色谱法测定甲肝灭活疫苗中的2-苯氧基乙醇含量

目的 建立反相高效液相色谱法（RP-HPLC法）测定甲型肝炎灭活疫苗中2-苯氧基乙醇的含量.方法采用C18柱,以50%乙腈为流动相,流速为1.0 mL/min,检测波长为270 nm,柱温为室温.以外标法测定含量.结果 2-苯氧基乙醇的浓度线性范围是0.55～111μg/mL（r=0.9995）,平均回收率为100.37%,RSD为1.77%.结论 RP-HPLC法可用于甲型肝炎灭活疫苗中2-苯氧基乙醇的含量测定.     

Physicochemical and Immunological Characterization of N,N,N-Trimethyl Chitosan-Coated Whole Inactivated Influenza Virus Vaccine for Intranasal Administration

Purpose  The purpose of this study was the development and physicochemical and immunological characterization of intranasal (i.n.) vaccine formulations of whole inactivated influenza virus (WIV) coated with N,N,N-trimethyl chitosan (TMC). Methods  Synthesized TMCs with a degree of quarternization of 15% (TMC15) or 37% (TMC37) were tested in vitro for their ability to decrease the transepithelial resistance (TEER) of an epithelial cell monolayer. TMC15- and TMC37-coated WIV (TMC15-WIV and TMC37-WIV) were characterized by zeta potential measurements, dynamic light scattering, electron microscopy and gel permeation chromatography. Mice were vaccinated i.n. with selected vaccine formulations and immunogenicity was determined by measuring serum hemagglutination inhibition (HI) and serum IgG, IgG1 and IgG2a/c titers. Also a pulse-chase study with TMCs in solution administered i.n. 2 h prior to WIV was performed. Protective efficacy of vaccination was determined by an aerosol virus challenge. Results  TMC37 induced a reversible decrease in TEER, suggesting the opening of tight junctions, whereas TMC15 did not affect TEER. Simple mixing of (negatively charged) WIV with TMC15 or TMC37 resulted in positively charged particles with TMCs being partially bound. Intranasal immunization with TMC37-WIV or TMC15-WIV induced stronger HI, IgG, IgG1 and IgG2a/c titers than WIV alone. TMC37-WIV induced the highest immune responses. Both TMC15-WIV and TMC37-WIV provided protection against challenge, whereas WIV alone was not protective. Intranasal administration of TMC prior to WIV did not result in significant immune responses, indicating that the immunostimulatory effect of TMC is primarily based on improved i.n. delivery of WIV. Conclusions  Coating of WIV with TMC is a simple procedure to improve the delivery and immunogenicity of i.n. administered WIV and may enable effective i.n. vaccination against influenza.     

A Thermostable Dissolving Microneedle Vaccine with Recombinant Protein of Botulinum Neurotoxin Serotype A

Background: As a Class A bioterrorism agent, botulinum neurotoxin serotype A (BoNT/A) carries the risk of being used by terrorists to cause mass poisoning. The microneedle (MN) patch has a great potential for application as a novel vaccine delivery method. The aim of this study is to develop a thermally stable, dissolving microneedle patch for the delivery of a recombinant protein vaccine using a recombinant C-terminal heavy chain of BoNT/A (Hc of BoNT/A, AHc) to prevent botulism. Methods: Fish gelatin, a natural non-toxic and bacteriostatic material, was selected as the microneedle matrix for the preparation of the dissolving microneedle vaccine. Subsequently, the mechanical performance, bacteriostatic properties, vaccination effect, and stability of the microneedle patches were evaluated using instruments such as the displacement-force test station and optical coherence tomography (OCT) scanner. Results: Fish gelatin matrix at high concentrations has good bacteriostatic properties, and excellent mechanical performance and vaccination effect, meeting the necessities of a vaccine. In both in vivo and in vitro neutralization experiments, MN vaccines containing different antigen doses achieved the same protective efficacy as subcutaneous vaccinations, protecting mice against 10⁶ LD₅₀ of BoNT/A injected intraperitoneally. Thermal stability analysis of the MN vaccines revealed that the fish gelatin matrix protected the AHc vaccine from protein denaturation even after 7 days of storage at 37 °C and enabled the vaccine patches to maintain good immunogenicity and protective efficacy even after 6 months of storage at room temperature. Conclusion: In this study, we successfully prepared a bacteriostatic MN patch using a fish gelatin matrix that not only has a good vaccination effect, but also obviates the need for a cold chain for the AHc vaccine, providing the possibility of rapid, painless, and large-scale vaccination.     

Analytical and Preformulation Characterization Studies of Human Papillomavirus Virus-Like Particles to Enable Quadrivalent Multi-Dose Vaccine Formulation Development

Introducing multi-dose formulations of Human Papillomavirus (HPV) vaccines will reduce costs and enable improved global vaccine coverage, especially in low- and middle-income countries. This work describes the development of key analytical methods later utilized for HPV vaccine multi-dose formulation development. First, down-selection of physicochemical methods suitable for multi-dose formulation development of four HPV (6, 11, 16, and 18) Virus-Like Particles (VLPs) adsorbed to an aluminum adjuvant (Alhydrogel®, AH) was performed. The four monovalent AH-adsorbed HPV VLPs were then characterized using these down-selected methods. Second, stability-indicating competitive ELISA assays were developed using HPV serotype-specific neutralizing mAbs, to monitor relative antibody binding profiles of the four AH-adsorbed VLPs during storage. Third, concentration-dependent preservative-induced destabilization of HPV16 VLPs was demonstrated by addition of eight preservatives found in parenterally administered pharmaceuticals and vaccines, as measured by ELISA, dynamic light scattering, and differential scanning calorimetry. Finally, preservative stability and effectiveness in the presence of vaccine components were evaluated using a combination of RP-UHPLC, a microbial growth inhibition assay, and a modified version of the European Pharmacopoeia assay (Ph. Eur. 5.1.3). Results are discussed in terms of analytical challenges encountered to identify and develop high-throughput methods that facilitate multi-dose formulation development of aluminum-adjuvanted protein-based vaccine candidates.     

Use of Biophysical Characterization in Preformulation Development of a Heavy-Chain Fragment of Botulinum Serotype B: Evaluation of Suitable Purification Process Conditions

PURPOSE: The purpose of this study was to investigate the physicochemical and structural characteristics of recombinant botulinum serotype B (rBoNTB(Hc)) under various conditions and to use the information in evaluating suitable purification process conditions. METHODS: The solubility of rBoNTB(Hc) was evaluated at pH 4, 5, 6 7.5, 8, and 9. Secondary structure was evaluated using circular dichroism, and conformational stability was monitored using highsensitivity differential scanning calorimetry. Hydrophobic interaction chromatography, size exclusion chromatography-high performance liquid chromatography (SEC-HPLC), sodium dodecyl sulfate-poly acrylamide gel electrophoresis (SDS-PAGE), peptide mapping, and UV spectroscopy were used to monitor stability under the various conditions. RESULTS: The secondary structure of rBoNTB(Hc) consists predominantly of beta-sheets. Solubility of rBoNTB(Hc) was lowest at its pI and highest at low and high pH. In the presence of NaCl, however, solubility decreased with increase in pH. Conformational and chemical stability are improved below pH 7.5. In the presence of 150 mM NaCl at high pH, conformational and chemical stability of rBoNTB(Hc) are further decreased. The study suggests that the purification process should minimize exposure of rBoNTB(Hc) to high pH and salt conditions. CONCLUSIONS: Optimal stability of rBoNTB(Hc) is achieved at low pH. The biophysical and analytical studies provide us with an understanding of rBoNTB(Hc) stability behavior in solution and assists in developing efficient purification conditions.     

动态浊度法测定注射用高纯度尿促性素中细菌内毒素的含量

目的建立注射用高纯度尿促性素中细菌内毒素定量的检查方法。方法采用动态浊度法考察注射用高纯度尿促性素对鲎试剂的干扰作用。结果注射用高纯度尿促性素进行10～80倍稀释即可以有效地消除其对鲎试剂的干扰。结论动态浊度法和凝胶法都可以用于检测注射用高纯度尿促性素中的细菌内毒素。     

酮咯酸异丙酯静脉注射脂肪乳剂的处方前研究

目的 对酮咯酸前体药物酮咯酸异丙酯进行处方前研究。方法 合成酮咯酸异丙酯,建立HPLC-UV方法并进行方法学验证。对酮咯酸异丙酯溶解度、油水分配系数和降解规律等理化性质进行研究,考察加速降解实验中的原料稳定性和原辅料相容性。结果 酮咯酸异丙酯在水中难溶（溶解度52.66 μg·mL^-1）,但可以和油相混溶,其LogP值为3.95±0.03。酮咯酸异丙酯的分析方法线性关系良好,仪器精密度良好（RSD<2%）,回收率较高（>99.5%）。在给定条件下,酮咯酸异丙酯的溶液稳定性随pH和温度升高而降低。酮咯酸异丙酯可在大鼠血浆和肝匀浆溶液中迅速降解,例如,在50%大鼠血浆溶液或20%肝匀浆溶液中,酮咯酸异丙酯的降解速率常数（k_obs）分别为0.51 min^-1和0.15 min^-1。酮咯酸异丙酯在高温、高湿环境下较稳定,但对光照敏感;原辅料相容性同样证实了这一点。结论 酮咯酸异丙酯在溶解度、分配系数、降解规律、原料稳定性和原辅料相容性方面,具备了制成静脉注射乳剂的适宜条件,为开发新型酮咯酸注射剂提供了实验依据。     

Functional EL-HN Fragment as a Potent Candidate Vaccine for the Prevention of Botulinum Neurotoxin Serotype E

Clostridium botulinum produces botulinum neurotoxin (BoNT), which is the most toxic known protein and the causative agent of human botulism. BoNTs have similar structures and functions, comprising three functional domains: catalytic domain (L), translocation domain (HN), and receptor-binding domain (Hc). In the present study, BoNT/E was selected as a model toxin to further explore the immunological significance of each domain. The EL-HN fragment (L and HN domains of BoNT/E) retained the enzymatic activity without in vivo neurotoxicity. Extensive investigations showed EL-HN functional fragment had the highest protective efficacy and contained some functional neutralizing epitopes. Further experiments demonstrated the EL-HN provided a superior protective effect compared with the EHc or EHc and EL-HN combination. Thus, the EL-HN played an important role in immune protection against BoNT/E and could provide an excellent platform for the design of botulinum vaccines and neutralizing antibodies. The EL-HN has the potential to replace EHc or toxoid as the optimal immunogen for the botulinum vaccine.     

精制蛇毒酶的毒理学研究

摘要目的观察精制蛇毒酶的安全性。方法小鼠100只,随机分成两组,尾静脉注射或腹腔注射精制蛇毒酶后观察动物出现的急性毒性反应,计算半数致死量（LD50）。小鼠120只,随机分为4组,各30只;家兔40只,随机分成4组。观察不同剂量组小鼠连续腹腔给药90 d,家兔静脉给药45 d（隔天一次）的健康状况。在给药后第91天采血,检测丙氨酸氨基转移酶、尿素氮和血常规,并对肝肾组织作病理学检查。结果精制蛇毒酶小鼠尾静脉给药的半数致死量（ivLD50）为6.695 U&#8226;kg－1,90%的可信限为5.434～7.956 U&#8226;kg－1;小鼠腹腔给药的半数致死量（ipLD50）为4.599 U&#8226;kg－1,90%的可信限为3.735～5.462 U&#8226;kg－1;各剂量小鼠和家兔肝、肾功能及血常规指标与空白组比较均差异无统计学意义（均 P＞0.05）,病理组织学检查未见明显异常。结论在实验剂量范围内,精制蛇毒酶属低毒性。乳膏中蛇毒酶的含量为1.25×10－2 U&#8226;g－1,按成人用量0.05 g&#8226;cm－1（6.25×10－4 U&#8226;cm－1酶活力）局部用药,其用量安全可靠。