Conventional influenza vaccines influence the performance of a universal influenza vaccine in mice

Universal influenza vaccines are designed to protect against diverse strains of influenza virus. Preclinical testing of new vaccine candidates is usually done in naïve animals, despite intended use in the human population with its varied immune history including responses to previous vaccinations. As an approach more relevant to human use, we tested a candidate universal influenza vaccine in mice with a history of conventional vaccination. Female BALB/c mice were given two intramuscular doses of inactivated influenza vaccine (IIV) or diphtheria and tetanus toxoids vaccine (DT), one month apart. Another group was given two intranasal doses of live attenuated influenza virus (LAIV). One month after the second dose, mice were given the universal influenza vaccine: recombinant adenoviruses expressing influenza A nucleoprotein (A/NP) and matrix 2 (M2) (A/NP + M2-rAd). Immune responses to universal vaccine antigens A/NP and M2 were assessed by ELISA and interferon-γ ELISPOT. Protection was tested by challenge with mouse-adapted A/FM/1/47 (H1N1) and monitoring for weight loss and survival. Universal vaccine performance was enhanced, inhibited or unaffected by particular prior vaccinations. Mice given Afluria IIV and LAIV had greater antibody and T-cell response to A/NP than mice without prior vaccination, providing examples of enhanced A/NP + M2-rAd performance. Though Fluvirin IIV partially inhibited, the universal vaccine still provided considerable protection unlike conventional vaccination. Fluzone IIV and DT had no effect on A/NP + M2-rAd performance. Thus our results demonstrate that universal vaccine candidate A/NP + M2-rAd was at least partially effective in mice with diverse prior histories. However, the degree of protection and nature of the immune responses may be affected by a history of conventional vaccination and suggests that performance in humans would be influenced by immune history.     

Analysis of variables of plasmid transformation of a bacterial vaccine: studies on recombinant BCG

Stepwise regression analysis was applied to evaluate the strength order of the effect of five explanatory variables on the transformation of BCG substrains by electroporation with hybrid shuttle plasmid [pAL5000:pIJ666] and derived as YUB plasmids containing a kanamycin resistance selection marker. From 66 successful transformations, data of 42 transformations of the Pasteur 1172P2 BCG substrain are analysed. The estimated parameters in the multiple linear regression model show that the association of the explanatory variables with the explained variable, i.e. the efficiency of the transformation of BCG expressed in c.f.u./microgram DNA, in decreasing strength order is: concentration of the plasmid DNA; viability of the non-electroporated concentrated BCG suspensions; viability of the BCG cultures; age of the BCG cultures; and time constant of the electroporation. More extended analysis of other factors of the transformation will improve objective statistical inference regarding the biophysical and molecular biological interpretation of the transformation mechanism by electroporation of the different bacterial species. More precise understanding of optimal conditions of genetic transformation will be particularly important for developing recombinant BCG vaccines.     

Lysed BCG vaccines. 2. The effect of lysis on the immunogenicity and allergenicity of BCG vaccines

The authors have attempted to prepare lysed BCG vaccines retaining the protective antigens of the BCG cell wall and yet eliciting in experimental animals limited sensitivity to the tuberculin substances, the advantage sought being to retain the usefulness of the tuberculin following vaccination as an indicator of superinfection.     

Quality control of BCG vaccine by WHO: a review of factors that may influence vaccine effectiveness and safety

WHO oversees the quality control of BCG vaccine via a system that includes regular testing of products by in vitro methods and clinical trials. Three parent strains of BCG (Glaxo-1077, Tokyo-172, and Pasteur-1173P2) account for over 90% of the vaccines currently in use worldwide. Important characteristics of the vaccine preparations are summarized here, along with their physical-chemical properties. In instances where diagnostic criteria for tuberculosis are stringent, there is no evidence that when administered to newborns different preparations of BCG vaccine exhibit different efficacies; however, the incidence of BCG-associated adverse reactions does correlate with the type of preparation. Other factors, including dose, administration technique, and recipient characteristics are also important in determining vaccine-associated reactions.     

Development and clinical testing of multivalent vaccines based on a diphtheria-tetanus-acellular pertussis vaccine: difficulties encountered and lessons learned

The widespread use of whole-cell pertussis vaccines in the second half of the 20th century have reduced the incidence of the disease significantly. However, in some countries, concerns about the reactogenicity and potential neurological damage associated with whole-cell vaccines led to a decrease in vaccine acceptance and an increase in morbidity and mortality of pertussis in several countries. This prompted the development of less reactogenic acellular pertussis vaccines combined with diphtheria and tetanus toxoids, initially in Japan and later in other countries. In Europe, the improved diphtheria, tetanus and acellular pertussis (DTPa) vaccine was first introduced in March 1994.The pertussis component of this DTPa vaccine, developed by Glaxo SmithKline, consists of pertussis toxoid, filamentous haemagglutinin and pertactin. The vaccine is well tolerated, with a lower incidence of adverse reactions than after administration of whole-cell vaccines.The long-lasting efficacy and effectiveness of DTPa vaccines have been extensively documented and these are now the cornerstone of a large range of combined vaccines including DTPa-hepatitis B (HBV), DTPa-inactivated polio (IPV) and DTPa-HBV-IPV. A lyophilised Haemophilus influenzae type b (Hib) vaccine can be reconstituted with all of these liquid combinations. The introduction of well-tolerated and efficacious DTPa vaccines and their more polyvalent combinations has improved the acceptance and simplified the implementation of childhood immunisation. This paper is a review of the technical and scientific difficulties encountered and the lessons learned over the 10-year period that it took to develop and introduce six multivalent vaccines using the Glaxo SmithKline DTPa as a building block.     

Immunisation with the BCG and DTPw vaccines induces different programs of trained immunity in mice

In addition to providing pathogen-specific immunity, vaccines can also confer nonspecific effects (NSEs) on mortality and morbidity unrelated to the targeted disease. Immunisation with live vaccines, such as the BCG vaccine, has generally been associated with significantly reduced all-cause infant mortality. In contrast, some inactivated vaccines, such as the diphtheria, tetanus, whole-cell pertussis (DTPw) vaccine, have been controversially associated with increased all-cause mortality especially in female infants in high-mortality settings. The NSEs associated with BCG have been attributed, in part, to the induction of trained immunity, an epigenetic and metabolic reprograming of innate immune cells, increasing their responsiveness to subsequent microbial encounters. Whether non-live vaccines such as DTPw induce trained immunity is currently poorly understood. Here, we report that immunisation of mice with DTPw induced a unique program of trained immunity in comparison to BCG immunised mice. Altered monocyte and DC cytokine responses were evident in DTPw immunised mice even months after vaccination. Furthermore, splenic cDCs from DTPw immunised mice had altered chromatin accessibility at loci involved in immunity and metabolism, suggesting that these changes were epigenetically mediated. Interestingly, changing the order in which the BCG and DTPw vaccines were co-administered to mice altered subsequent trained immune responses. Given these differences in trained immunity, we also assessed whether administration of these vaccines altered susceptibility to sepsis in two different mouse models. Immunisation with either BCG or a DTPw-containing vaccine prior to the induction of sepsis did not significantly alter survival. Further studies are now needed to more fully investigate the potential consequences of DTPw induced trained immunity in different contexts and to assess whether other non-live vaccines also induce similar changes.     

Quantitative evaluation of the effectiveness of Connaught freeze-dried BCG vaccine in mice and in guinea-pigs

Although the field trials carried out by the Medical Research Council of Great Britain demonstrated that BCG vaccination can confer a substantial degree of immunity against tuberculous infection, it does not follow that BCG substrains other than the one used for those trials will produce equally favourable results. In fact, there is increasing evidence that different BCG strains may differ widely in their protective potency. The experiments described here further confirm these differences. They also show how the determination of the minimum dose of a BCG vaccine capable of delaying the development of tuberculous infection in mice and in guinea-pigs can yield reproducible data that may help to characterize individual BCG strains.     

The effect of undernutrition on immunological responses to BCG and TAB vaccines in mice maintained on a natural diet.

A study was made on the effect of undernutrition on the immunological responses of mice to TAB and BCG vaccines. The mice were fed a diet comprising chapati and germinated grams; one group was fed ad libitum while another was given half the quantity consumed by the first group. The undernourished mice showed a poor immune response to BCG: only 23% showed a positive reaction to foot pad challenge with purified protein derivative, compared with 76% of the well-fed mice. The mean increase in thickness of the foot pad was also significantly smaller in the undernourished mice. Antibody titres against the H and O antigens of TAB were essentially similar in both groups of mice. The results suggest that undernutrition depresses cell-mediated immune responses but not humoral responses.     

Differential productions of lipid virulence factors among BCG vaccine strains and implications on BCG safety

Safety of BCG is a major concern in countries with a high burden of HIV/AIDS. Current BCG vaccine comprises of a heterogeneous group of substrains showing genotypic differences. The impact of these differences on BCG efficacy and safety remains unknown. Here we show that three BCG substrains, BCG-Japan, -Moreau, and -Glaxo, do not produce phthiocerol dimycocerosates (PDIMs) and phenolic glycolipids (PGLs), two cell wall lipids known to be important for the virulence of Mycobacterium tuberculosis and Mycobacterium bovis, suggesting that these BCG strains are more attenuated than others. We found that there is a good correlation between the ability of BCG strains to produce these two lipids and the propensity of BCG to induce complications following vaccination in children, which provides a partial explanation for the molecular mechanisms of BCG reactogenicity. Our finding has important implications for national immunization programmes particularly in HIV endemic countries. We suggest that PDIMs/PGLs analysis could offer a practical means for assessing the safety of various BCG vaccine strains currently used in the world.     

Epidemiologic findings on the relationship of time of day and time since last meal to five clinical variables: serum cholesterol, hematocrit, systolic and diastolic blood pressure, and heart rate

Data from 10,559 men and women, aged 30–64, participating in the morning and afternoon in a Chicago Health Department multiphasic screening project, were used to evaluate the relationship of time of day and time since last meal to group mean serum cholesterol, hematocrit, systolic and diastolic blood pressure, and heart rate. Serum cholesterol showed no definable differences with time of day and time since last meal. Hematocrit values tended to be slightly higher in the morning than in the afternoon and showed no consistent differences with time since last meal. Systolic blood pressure values, but not diastolic, were slightly higher in the afternoon than in the morning. Mean heart rates tended to be slightly higher in the afternoon and lower with time elapsed since last meal. All these differences were small and not of an order to present significant problems with regard to carrying out mass screening for these variables over the course of the day.     

卡介苗接种的职业安全危险因素及对策

目的 揭示卡介苗接种过程中存在的职业安全危险因素,减少职业伤害风险.方法 观察接种卡介苗过程中的职业安全环节,引导医务人员在卡介苗接种各环节做好防护.结果 通过对接种过程的临床观察,提出可靠的防护方法,在接种过程中按照卡介苗接种流程操作,3年中无一例医务人员发生结核分枝杆菌感染.结论 只要从卡介苗的检查、使用、废弃空安瓿的处理过程中做好防护,对有利器损伤的医务人员及时采取预防治疗,可以防止感染结核病,防护措施值得推广.     

茶多酚对辐照后小鼠生存状况与血中白细胞数影响的研究

为评价茶多酚对小鼠的抗辐射作用 ,将 60只小鼠作为抗辐射I组 ,动态观察白细胞数。另 60只小鼠为抗辐射Ⅱ组 ,进行存活试验。结果表明 ,小鼠经口给予不同剂量茶多酚 ,辐照后各次试验中小鼠血中白细胞数均与对照组无显著性差异 ,茶多酚在大剂量照射时对小鼠白细胞保护作用不明显。 0 83和 2 5 0mg kgBW组小鼠存活率和对照组间比较 ,均有极显著性差异 (P <0 0 1 ) ,对照组辐射后 30天无一存活。这一结果显示茶多酚能显著提高辐照小鼠存活率     

Therapeutic vaccination against HSV-2: influence of vaccine formulation on immune responses and protection in mice

Therapeutic immunisation may represent a means of influencing viral infections that persist in the host by modulating the nature or level of host immunity. To assess the influence of the form of the antigenic stimulus on immunity to type-2 herpes simplex virus (HSV-2), mice pre-infected with sublethal doses of HSV-2 were immunised with various HSV-2 vaccine formulations prior to challenge infection with heterologous HSV-1. Measurements of interleukin-2 (IL-2), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) levels in mouse spleen cell cultures restimulated in vitro with HSV-2 antigens showed that, depending on the form of HSV-2 antigen preparation used in this therapeutic context, changes in the levels of these cytokines could be effected. Measurement of HSV-specific antibody by serological tests support the contention that immunisation of HSV-2-infected mice can either enhance the existing Th1-like immune response elicited following HSV-2 infection, or modulate this response towards a more Th2-like profile, and this is dependent on the form of the antigenic stimulus. The degree of protection against subsequent lethal, heterologous HSV-1 challenge infection varied according to the nature of the infection and the immunisation history of the animals.     

WHO Working Group meeting on standardization of acellular pertussis vaccines: Potency assay Beijing, China, 7-9 November 2007

New acellular pertussis vaccines have recently been developed in China and India. In this context, potency testing and potential improvements of the protective animal models with inclusion of a reference material were recognized as critical issues in the quality assessment of acellular pertussis vaccines. One of these models, namely Modified Intracerebral Challenge Assay (MICA), is currently used as a potency assay in Japan, China and Korea. A collaborative study comparing whole cell references, a candidate acellular pertussis vaccine reference (JNIH-3) and various acellular pertussis products was undertaken in 2006. The results of the collaborative study showed that MICA worked reliably and gave consistent results between laboratories. JNIH-3 was found to give similar dose-response lines to a variety of acellular pertussis vaccines and DTaP formulations, irrespective of the differences in acellular pertussis components. The WHO Working Group agreed that proposal for establishing JNIH-3 as the First International Standard for acellular pertussis vaccine in MICA should be submitted to the Expert Committee on Biological Standardization at its meeting in October 2008.     

The influence of BCG vaccine strain on mycobacteria-specific and non-specific immune responses in a prospective cohort of infants in Uganda

Background

Globally, BCG vaccination varies in efficacy and has some non-specific protective effects. Previous studies comparing BCG strains have been small-scale, with few or no immunological outcomes and have compared TB-specific responses only. We aimed to evaluate both specific and non-specific immune responses to different strains of BCG within a large infant cohort and to evaluate further the relationship between BCG strain, scarring and cytokine responses.

Methods

Infants from the Entebbe Mother and Baby Study (ISRCTN32849447) who received BCG-Russia, BCG-Bulgaria or BCG-Denmark at birth, were analysed by BCG strain group. At one year, interferon-gamma (IFN-γ), interleukin (IL)-5, IL-13 and IL-10 responses to mycobacteria-specific antigens (crude culture filtrate proteins and antigen 85) and non-mycobacterial stimuli (tetanus toxoid and phytohaemagglutinin) were measured using ELISA. Cytokine responses, scar frequency, BCG associated adverse event frequency and mortality rates were compared across groups, with adjustments for potential confounders.

Results

Both specific and non-specific IFN-γ, IL-13 and IL-10 responses in 1341 infants differed between BCG strain groups including in response to stimulation with tetanus toxoid. BCG-Denmark immunised infants showed the highest cytokine responses. The proportion of infants who scarred differed significantly, with BCG scars occurring in 52.2%, 64.1% and 92.6% of infants immunised with BCG Russia, BCG-Bulgaria and BCG-Denmark, respectively (p < 0.001). Scarred infants had higher IFN-γ and IL-13 responses to mycobacterial antigens only than infants without a scar. The BCG-Denmark group had the highest frequency of adverse events (p = 0.025). Mortality differences were not significant.

Conclusions

Both specific and non-specific immune responses to the BCG vaccine differ by strain. Scarring after BCG vaccination is also strain-dependent and is associated with higher IFN-γ and IL-13 responses to mycobacterial antigens. The choice of BCG strain may be an important factor and should be evaluated when testing novel vaccine strategies that employ BCG in prime–boost sequences, or as a vector for other vaccine antigens.     

TgPVR21 mice for testing type-3 oral poliovirus vaccines: role of clinical observation and histological examination

Transgenic mice susceptible to poliovirus (TgPVR mice) have been used to study poliovirus neurovirulence and attenuation. It was shown recently that mouse line TgPVR21 may be a suitable model to evaluate neurovirulence safety of oral poliovirus vaccine. It was important to determine whether TgPVR21 mice are sensitive enough to discriminate between type-3 reference and ‘marginal’ vaccines, i.e. those that failed the monkey test while containing only slightly increased amounts of neurovirulent revertants at position 472 of the viral genome as measured by a molecular assay MAPREC. Data presented here demonstrate that TgPVR21 mice are not less sensitive than monkeys in the detection of marginal vaccines. In contrast to the monkey neurovirulence test, which is based on histological examination of the CNS, the TgPVR21 mouse neurovirulence test revealed marginal vaccines by simple analysis of clinical signs without requiring a laborious histological examination.     

Biodistribution assessment of cationic pullulan nanogel,a nasal vaccine delivery system,in mice and non-human primates

Cationic cholesteryl-group–bearing pullulan nanogel (cCHP-nanogel) is an effective drug-delivery system for nasal vaccines. However, cCHP-nanogel-based nasal vaccines might access the central nervous system due to its close proximity via the olfactory bulb in the nasal cavity. Using real-time quantitative tracking of the nanogel-based nasal botulinum neurotoxin and pneumococcal vaccines, we previously confirmed the lack of deposition of vaccine antigen in the cerebrum or olfactory bulbs of mice and non-human primates (NHPs), rhesus macaques. Here, we used positron emission tomography to investigate the biodistribution of the drug-delivery system itself, cCHP-nanogel after mice and NHPs were nasally administered with ¹⁸F-labeled cCHP nanogel. The results generated by the PET analysis of rhesus macaques were consistent with the direct counting of radioactivity due to ¹⁸F or ¹¹¹In in dissected mouse tissues. Thus, no depositions of cCHP-nanogel were noted in the cerebrum, olfactory bulbs, or eyes of both species after nasal administration of the radiolabeled cCHP-nanogel compound. Our findings confirm the safe biodistribution of the cCHP-nanogel-based nasal vaccine delivery system in mice and NHPs.