Clinical trials of oral recombinant bivaccine against variola and hepatitis B during double vaccination

Clinical trials of oral live recombinant embryonic variola and hepatitis B bivaccine as tablets (Revax-BT) were performed. When volunteers were prevaccinated with oral variola vaccine first in a small dose and, 7, 14, 30, 90, and 180 days later, in a larger dose, a slight reactoginicity was sometimes observed after the first vaccination (with a small dose) whereas revaccination with a larger dose did not give rise to any clinical manifestations. A month after vaccination, a protective level of virus-neutralizing antibodies to vaccinia virus (VV) was observed in 90-100% of the volunteers twice immunized with the bivaccine (in a small dose and in a larger one at an administration intervals of 1-2 weeks under remote revaccination while 6-9 months following vaccination, this level was recorded in 80% of the volunteers. A month following vaccination, 50-55% seroconversion to VV was observed in the volunteers twice immunized with the bivaccine (at an interval of 1 or 3-6 months). Cellular immunity to VV was low (0-20%). Double immunization of volunteers with the oral bivaccine under remote vaccination failed to produce the significant levels of humoral and cellular immune responses to hepatitis B markers. Recombinant VV was not recorded in any blood, saliva, and urine samples taken in the volunteers twice immunized with the bivaccine.     

乙型肝炎血源疫苗作体内免疫提高抗-HBs效价的研究

本文介绍了用乙型肝炎血源性疫苗进行人体内免疫提高人体抗-HBs效价的结果。21名正常献血员抗-HBs阳性志愿者分组进行不同免疫剂量的观察,结果表明提高志愿者的体内抗体效价,疫苗使用剂量以100μg/次为宜。抗-HBs效价免疫后一个月逐步上升,最高峰值维持一个月左右。本实验还证实曾接受过疫苗免疫的志愿者再次免疫后的各项反应优于未免疫的志愿者。此工作对制备抗-HBs人McAb寻找高效价抗-HBs血源提供了可靠依据。     

Characteristics of the immunological and protective effect in the simultaneous and separate use of live and killed influenza vaccines

Simultaneous immunization with inactivated and live influenza vaccines is characterized by a more rapid and intensive formation of local protection and humoral immunity persisting for 5 months at a higher level than after separate administration of inactivated and live vaccines. The live vaccine was found to be the major factor enhancing the immune response and local protection in combined immunization. Administration as components of a live bivaccine of influenza serotype A viruses with a different degree of attenuation was not accompanied by higher reactogenicity but led to a sharp decrease of immunogenic activity that indicated incompatibility of such viruses in a bivaccine.     

Oral spray immunization may be an alternative to intranasal vaccine delivery to induce systemic antibodies but not nasal mucosal or cellular immunity

Sixty-five healthy adult volunteers were immunized four times at 1-week intervals with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1) without adjuvant. The vaccine was administered as nasal spray with a newly developed device to secure intranasal delivery (OptiMist, OptiNose AS, Oslo, Norway), as regular nasal spray, nasal drops or as an oral spray. Significant IgA-antibody responses in nasal secretions were induced in volunteers immunized intranasally but not after oral spray immunization. In saliva, IgA antibodies were only marginally amplified even after oral spray immunizations. At least 73% of the volunteers belonging to any group of vaccine delivery reached serum haemagglutination inhibition titres of 40 or higher, considered protective against influenza, after only two vaccine doses. Those who had the vaccine delivered intranasally also showed evidence from in vitro secretion of granzyme B that cytotoxic T cells had been stimulated. Although immunization with the breath-actuated OptiMist device and nasal drops were superior with respect to both mucosal and systemic immune responses, oral spray immunization might still be considered for studies of mucosal adjuvants that are not yet acceptable for intranasal use.     

High rate of insufficient antibody titers after single-day immunization with human diploid-cell-strain vaccine against rabies

Summary We examined the possibility of simplifying the currently recommended immunization schedule against rabies. Four groups of 11 healthy volunteers were each immunized with either one, two, four, or eight doses of 0.1 ml human diploid cell vaccine (HDCV) intradermally on 1 single day. Antibody titers in serum were determined using a rapid fluorescent focus inhibition test. Geometric mean antibody titers 10, 30 and 90 days after immunization were all >0.5 IU/ml, which is considered protective. A dose-proportional increase in the geometric mean antibody titer was observed for all four groups. However, at each dose level, at least 1 of the 11 volunteers on day 30 and 2 of the 11 volunteers on day 90 had insufficient antibody titers <0.5 IU/ml. Single-day immunization against rabies with HDCV vaccine cannot be recommended because of the unacceptably high failure rate.Abbreviations DEV Duck-embryo-vaccine - GMT geometric mean titer - HDCV human diploid cell vaccine - IU international units     

The present epidemiologic status and prognosis in measles]

During 1990 and partly also 1991, after a practically 10-year zero incidence of measles on the territory of the Czech Republic a measles epidemic broke out. The most severely affected group were adolescents aged 15-19 years who were immunized only by a single dose of vaccine. Conversely the lowest morbidity was recorded in 2-9-year-old children who were immunized already with two doses. The cause of the epidemic was primary failure of the vaccine leading to a low level of collective immunity in some population age brackets. The authors discuss and explain the strategy of immunization against measles involving two doses of vaccine after a 6-10-month interval. In the conclusion possibilities to achieve permanent elimination of measles on our territory are discussed.     

Immunity following intranasal administration of an inactivated,freeze-dried A/England/42/72 vaccine

A group of 23 student volunteers were each inoculated intranasally with 400 IU of inactivated, freeze-dried A/England/42/72 vaccine. Only one volunteer showed a four-fold rise in serum HI antibody following immunization, and the mean increase in serum HI antibody (gmt) for all volunteers did not increase two-fold. Thirteen of the volunteers developed detectable levels of nasal wash neutralizing antibody after immunization; local antibody was most commonly found in volunteers who produced a detectable but less than four-fold fise in serum antibody titre, and who produced nasal washings with relatively high concentrations of protein and secretory IgA. Four weeks after immunization, the vaccinees and a matched group of control subjects were inoculated with attenuated A/England/42/72 (MRC-7) virus. Evidence of infection was found in 14 of 23 (61 per cent) of control subjects and in seven of 23 (30 per cent) of immunized volunteers. This result showed a significant protection (P = 0.04) against challenge virus infection for volunteers given intranasal vaccine.     

Oral and rectal immunization of adult female volunteers with a recombinant attenuated Salmonella typhi vaccine strain.

An attenuated strain of Salmonella typhi delta(cya) delta(crp-cdt) delta(asd) expressing a gene encoding a hepatitis B virus core-pre-S protein was tested in female adult volunteers for its ability to elicit a systemic and a mucosal immune response. Specifically, our purpose was to evaluate the potential of such a vaccine strain to induce specific secretory immunoglobulin A (sIgA) at genital and rectal surfaces. Oral and rectal routes of immunization were compared: oral immunization induced seroconversion against the bacterial lipopolysaccharide (LPS) in six out of seven volunteers, while after rectal immunization only one out of six volunteers seroconverted against LPS. To our disappointment, the latter volunteer was also the only one who seroconverted against the carried antigen (pre-S1), demonstrating the poor ability of this live vaccine to induce an immune response against the carried antigen. Anti-LPS sIgA was found in both the vaginal and cervical secretions of a volunteer who presented a strong seroconversion after oral immunization (16-fold increase in anti-LPS IgG). Smaller amounts of anti-LPS sIgA were found in the rectal secretions of one orally and one rectally immunized volunteer and in the saliva of three orally and one rectally immunized woman. Our data show for the first time that it is possible to induce specific sIgA in the genital and rectal tracts of women by using an S. typhi vaccine strain.     

The significance of hemolysing-inhibiting antibodies in protection against measles

The occurence of hemagglutinating-inhibiting (HI), hemolysinginhibiting (HLI) and nucleocapsid complement fixing (NC-CF) antibodies in serum samples from individuals immunized with measles virus antigens under various conditions was analyzed. After regular measles infections all three kinds of antibodies were detectable and removal of HI antibodies by absorption with Tween 80 and ether treated virus material only caused an about 2-fold reduction of titers of HLI antibodies. Immunization with further attenuated measles vaccine also induced a production of antibodies detectable in the three different tests. However the response of non-HI HLI antibodies and NC-CF antibodies was relatively less pronounced than after regular measles. Immunization with three or four doses of Tween 80 ether treated inactivated measles vaccine caused a production of HI antibodies and in some cases NC-CF antibodies. Non-HI HLI antibodies were not detectable. The combined immunization with inactivated vaccine followed by further attenuated live vaccine caused the appearance of high titers of HI antibodies but in contrast to the situation of administration of only live vaccine non-HI HLI antibodies were not detectable. The significance of non-HI HLI antibodies in protection against disease also was indicated by observations on the reactions of individuals immunized with inactivated vaccine and subsequently exposed to wild measles virus. The non-HI HLI antibody response was poorer in the vaccinees who contracted a complicated infection as compared to those who had only a subclinical or a mitigated infection. An accentuated non-HI HLI antibody and NC-CF antibody response was seen in patients with subacute sclerosing panencephalitis. It is proposed that the failure of hitherto used inactivated measles vaccines is due to the absence of certain envelope antigens in the preparations which leads to a deficiency as concerns the capacity to induce a production of non-HI HLI antibodies.     

Influence of preimmunization antibody levels on the specificity of the immune response to related polysaccharide antigens

We studied the influence of preimmunization antibody level on the immune response of adults to one of two structurally related yet immunologically distinct type-specific polysaccharides from Type III Group B streptococcus and Type 14 pneumonococcus. Four weeks after immunization with multivalent pneumococcal vaccine, 20 subjects with low levels of antibody to Type III Group B streptococcus antigen had no significant increase in antibody to this antigen (P greater than 0.05), but all volunteers with moderate to high preimmunization antibody levels who were immunized with Pneumovax had significant increases (P less than 0.01). However, the streptococcal antibody response to pneumococcal Type 14 antigen was weaker and briefer than that in 10 adults given Type III Group B streptococcus vaccine(P less than 0.05). Preimmunization antibody levels influenced the immune response to a structurally similar polysaccharide antigen, but specific Type III polysaccharide antigen appeared necessary to induce a primary antibody response in "nonimmune" adults. We conclude that immunization of mothers with pneumococcal vaccine is not likely to prevent neonatal Type III Group B streptococcal infection, despite immunologic similarities between the two organisms.     

Immunization with subunit human immunodeficiency virus vaccine generates stronger T helper cell immunity than natural infection.

Healthy, human immunodeficiency virus seronegative (HIV-) volunteers were multiply immunized with a recombinant gp160 (rgp160) candidate acquired immunodeficiency syndrome (AIDS) vaccine. Peripheral blood lymphocytes from volunteers immunized with 40 micrograms or with 80 micrograms (two volunteers per group) of rgp160, as well as from control donors, were tested for T helper (Th) cell function either prior to immunization, 8 to 12 months after the third immunization, or 2 to 5 months after the fourth immunization. The Th cell functional tests included antigen-induced in vitro interleukin 2 (IL 2) production and proliferation in response to influenza A virus (FLU) and to four synthetic peptides of HIV gp120 and gp160, previously demonstrated to be recognized by T cells from HIV naturally infected patients. Our results demonstrate the following: (a) immunization of HIV- individuals with rgp160 results in IL 2 production and T cell proliferation in response to HIV determinants; (b) boosting with rgp160 enhances Th function; (c) HIV-specific Th function is up to 100-fold greater in the multiply immunized volunteers than that observed in asymptomatic, HIV-infected individuals; and (d) multiple immunization with rgp160 does not impair Th function to a non-HIV antigen such as influenza A virus. These results indicate that immunization of uninfected individuals with an HIV subunit vaccine results in much stronger Th cell immunity than does natural infection and suggests that vaccination against HIV may be possible.     

Nanogram Doses of Alum-Adjuvanted HBs Antigen Induce Humoral Immune Response in Mice When Orally Administered

Mucosal immunity elicited by plant-based and other orally administered vaccines can serve as the first line of defense against most pathogens infecting through mucosal surfaces, but it is also considered for systemic immunity against blood–borne diseases such as hepatitis B (HB). Previous oral immunization trials based on multiple administration of high doses of HBs antigen elicited an immune response; however, a reproducible and long-lasting immunization protocol was difficult to design. The objective of this study was to evaluate the effect of dose and timing of orally delivered alum-adsorbed antigen on the magnitude of the anti-HBs humoral response. Mice were immunized orally by gavage intubation or parenterally by intramuscular injection three times, once every 2 weeks, with doses of 5, 50, or 500 ng alum-adjuvanted HBsAg. A low dose (10 ng) of HBsAg was orally administered three times in different time intervals: 2, 4, 6, and 8 weeks. The three consecutive 5-ng oral doses of the antigen induced immune response at the protective level (≥10 mIU/ml), significantly higher than the reaction elicited by three 50 or 500 ng doses. In contrast, intramuscular delivery of these doses did not differ significantly; however, they induced a five to six times higher immune response than oral immunization. The 8-week period between each of the three oral immunizations appeared to be favorable to the anti-HBs humoral responses compared with the shorter schedules. The results presented here clearly identify the importance of low doses of antigen administered orally in extended intervals for a significantly higher anti-HBs response. This finding provides some indications concerning the strategy of orally administered vaccines, including plant-based ones.     

Age-dependent antibody response in mice and humans following oral influenza immunization

In order to compare the antibody response in serum and secretions from healthy young subjects and the elderly (>60 years), volunteers were immunized with the commercial inactivated influenza virus vaccine, by the usual (parenteral) route or orally. Also, young and old mice (mean age, 20 months) were orally immunized with live influenza virus. The older mice responded with a very slight rise in their serum and respiratory tract antibody levels compared with the young mice but showed no diminution in protection against lethal viral challenge. Elderly volunteers showed only slight serum antibody responses after parenteral immunization compared with the young. Neither group demonstrated a rise in serum antibody following oral immunization. With respect to the secretory IgA (SIgA) antibody response, certain differences were noted between the young and the elderly: the preimmunization levels of antibody to influenza virus were significantly greater in nasal secretions and saliva in the elderly as compared to the young volunteers, and the salivary antibody response was diminished in the elderly. This lack of a salivary antibody response in the elderly was explicable by the inverse relationship between the preimmunization SIgA antibody titers and the response to immunization. Oral immunization led to no more side effects than observed in the placebo control group.     

Dose-dependent circulating immunoglobulin A antibody-secreting cell and serum antibody responses in Swedish volunteers to an oral inactivated enterotoxigenic Escherichia coli vaccine

The immunogenicity of different preparations of an oral inactivated enterotoxigenic Escherichia coli (ETEC) vaccine was evaluated in Swedish volunteers previously unexposed to ETEC infection. The vaccine preparations consisted of recombinant cholera toxin B subunit (CTB) and various amounts of formalin-killed whole bacteria expressing the most prevalent colonization factor antigens (CFAs). Significant immunoglobulin A (IgA) antibody-secreting cell (ASC) responses against CTB and the various CFA components were seen in a majority of volunteers after two doses of ETEC vaccine independent of the vaccine lot given. The IgA ASC responses against CTB were significantly higher after the second than after the first immunization, whereas the CFA-specific IgA ASC responses were almost comparable after the first and second doses of ETEC vaccine. Two immunizations with one-third of a full dose of CFA-ETEC bacteria induced lower frequencies of IgA ASC responses against all the different CFAs than two full vaccine doses, i.e., 63 versus 80% for CFA/I, 56 versus 70% for CS1, 31 versus 65% for CS2, and 56 versus 75% for CS4. The proportion of vaccinees responding with rises in the titer of serum IgA antibody against the various CFA antigens was also lower after immunization with the reduced dose of CFA-ETEC bacteria. These findings suggest that measurements of circulating IgA ASCs can be used not only for qualitative but also for quantitative assessments of the immunogenicity of individual fimbrial antigens in various preparations of ETEC vaccine.     

人工合成免疫刺激DNA联合HBsAg DNA疫苗在HBV转基因鼠的免疫应答研究

目的 :探讨免疫刺激DNA序列联合基因免疫在HBV转基因鼠的免疫应答。方法 :用人工合成硫代修饰的免疫刺激DNA寡核苷酸 (CpGODN)与HBVS区基因真核表达载体 (V HBs)联合免疫HBsAg转基因鼠 ,通过ELISA观察小鼠血清HBsAg及抗 HBs抗体水平 ,并用免疫组化 (SP法 )及病理HE染色观察小鼠肝组织HBsAg表达量的改变及肝组织炎症活动度。结果 :V HBs联合CpGODN组 6只免疫鼠中有 2只血清抗 HBs抗体阳性 ,其平均效价为 (5 6 2 1± 15 16 )mU ml,血清HBsAg浓度在免疫后第 8周时有 2只转阴 ,而单用V HBs组及V 10 12对照组小鼠血清抗 HBs抗体均阴性、HBsAg含量无明显降低。V HBs +CpGODN组肝组织HBsAg的表达量低于V HBs组及对照组 ,并可见大量炎细胞浸润 ,炎症组织活动度积分明显高于V HBs组及对照组。结论 :CpGODN联合V HBs可增强其免疫应答及抗病毒效应。     

The inoculation properties of live recombinant influenza vaccine types A and B used separately and jointly in children 3 to 14]

The reactogenicity and immunizing activity of vaccine influenza virus A (H1N1) and B strains used as mono- and bi-preparations in children of 3 to 14 years was studied. No increased reactogenicity after the use of bivaccine was observed in the children. Febrile reactions as well as 9 other clinical symptoms which could indicate the reactogenicity of the vaccines were identical for mono- and bivaccine and corresponded to the requirements of the technical documents for the vaccine. The optimal conditions for the evaluation of the immunogenicity of the B component by HI test were developed, and the necessity of using additionally the enzyme immunoassay for this purpose is substantiated. The above method demonstrated that the immunogenicity of the live influenza type A and B vaccine was high in children. No significant inhibition of immunological parameters was observed when the two viruses were combined in the bivaccine.     

A final report on safety and immunogenicity of a bivalent aqueous subunit HBV vaccine

The bivalent form of an aqueous formalin-inactivated hepatitis B vaccine was evaluated for safety and immunogenicity in chimpanzees. To evaluate safety five animals were inoculated intravenously with vaccine containing 500 micrograms HBsAg and two animals with 50 micrograms. None of these animals developed hepatitis or any serologic marker indicative of the presence of residual live virus in the vaccine. Twenty-four animals were used to evaluate immunogenicity and protective efficacy. Seven of these immunized animals produced weak or no anti-HBs responses. Two doses of 50 micrograms HBsAg given subcutaneously 1 month apart protected each of four animals that were challenged with 10(3.5) CID50 HBV at 6 and 12 months after immunization and protected three of four animals challenged at 24 months against development of hepatitis or HBsAg. Three of 4 animals in each group immunized with two doses of 20, 10, or 5 micrograms HBsAg were similarly protected when challenged 6 months after immunization. Thirteen of 20 immunized animals that did not develop HBsAg after challenge with HBV developed anamnestic anti-HBs or anti-HBc responses between 2 and 18 months after challenge, indicating minimal replication of challenge virus. The time of onset and frequency of occurrence of these delayed responses was related to the titer of anti-HBs at the time of challenge. False positive Ausab test results were observed in quarantined chimpanzees. These were neither preceded by appearance of HBsAg nor accompanied by development of anti-HBc. In most cases these reactions were due to a reactant having a sedimentation coefficient and an electrophoretic mobility resembling that of IgM. This reactant generally did not appear to confer resistance to challenge with HBV. The humoral immune response was characterized as being entirely of the IgM class 2 weeks after immunization and switched entirely into the IgG class by 10-12 weeks after vaccine administration. At the time of challenge all animals with antibody had anti-HBs of subtype a.     

Dose-Dependent Circulating Immunoglobulin A Antibody-Secreting Cell and Serum Antibody Responses in Swedish Volunteers to an Oral Inactivated Enterotoxigenic Escherichia coli Vaccine

The immunogenicity of different preparations of an oral inactivated enterotoxigenic Escherichia coli (ETEC) vaccine was evaluated in Swedish volunteers previously unexposed to ETEC infection. The vaccine preparations consisted of recombinant cholera toxin B subunit (CTB) and various amounts of formalin-killed whole bacteria expressing the most prevalent colonization factor antigens (CFAs). Significant immunoglobulin A (IgA) antibody-secreting cell (ASC) responses against CTB and the various CFA components were seen in a majority of volunteers after two doses of ETEC vaccine independent of the vaccine lot given. The IgA ASC responses against CTB were significantly higher after the second than after the first immunization, whereas the CFA-specific IgA ASC responses were almost comparable after the first and second doses of ETEC vaccine. Two immunizations with one-third of a full dose of CFA-ETEC bacteria induced lower frequencies of IgA ASC responses against all the different CFAs than two full vaccine doses, i.e., 63 versus 80% for CFA/I, 56 versus 70% for CS1, 31 versus 65% for CS2, and 56 versus 75% for CS4. The proportion of vaccinees responding with rises in the titer of serum IgA antibody against the various CFA antigens was also lower after immunization with the reduced dose of CFA-ETEC bacteria. These findings suggest that measurements of circulating IgA ASCs can be used not only for qualitative but also for quantitative assessments of the immunogenicity of individual fimbrial antigens in various preparations of ETEC vaccine.     

Factors influencing African-American mothers' concerns about immunization safety: a summary of focus group findings

OBJECTIVE: To examine the vaccine safety concerns of African-American mothers who, despite concerns, have their children immunized. METHODS: Six focus groups of Atlanta-area African-American mothers who were very concerned about vaccine safety but whose children were fully vaccinated were conducted. RESULTS: Major factors influencing participants' concerns about immunizations included: lack of information and mistrust of the medical community and government. Factors that convinced parents to have their child immunized despite their concerns included social norms and/or laws supporting immunization and fear of the consequences of not immunizing. Suggestions given to reduce concerns included improving available information that addressed their concerns and provider-patient communication. CONCLUSIONS: Addressing mothers' concerns about immunization is important both from an ethical perspective, in assuring that they are fully informed of the risks and benefits of immunizations, as well as from a practical one, in reducing the possibility that they will decide not to immunize their child. Changes in the childhood immunization process should be made to reduce parental concern about vaccine safety. Some changes that may be considered include improved provider communication about immunizations and additional tailored information about the necessity and safety of vaccines.     

Mucosal and Systemic Immune Responses in Humans after Primary and Booster Immunizations with Orally Administered Invasive and Noninvasive Live Attenuated Bacteria

The mucosal and systemic immune responses after primary and booster immunizations with two attenuated live oral vaccine strains derived from a noninvasive (Vibrio cholerae) and an invasive (Salmonella typhi) enteric pathogen were comparatively evaluated. Vaccination with S. typhi Ty21a elicited antibody-secreting cell (ASC) responses specific for S. typhi O9, 12 lipopolysaccharide (LPS), as well as significant increases in levels of immunoglobulin G (IgG) and IgA antibodies to the same antigen in serum. A strong systemic CD4(+) T-helper type 1 cell-mediated immune (CMI) response was also induced. In contrast to results with Ty21a, no evidence of a CMI response was obtained after primary immunization with V. cholerae CVD 103-HgR in spite of the good immunogenicity of the vaccine. Volunteers who received a single dose of CVD 103-HgR primarily developed an IgM ASC response against whole vaccine cells and purified V. cholerae Inaba LPS, and seroconversion of serum vibriocidal antibodies occurred in four of five subjects. Serum IgG anti-cholera toxin antibody titers were of lower magnitude. For both live vaccines, the volunteers still presented significant local immunity 14 months after primary immunization, as revealed by the elevated baseline antibody titers at the time of the booster immunization and the lower ASC, serum IgG, and vibriocidal antibody responses after the booster immunization. These results suggest that local immunity may interfere with colonization of the gut by both vaccine strains at least up to 14 months after basis immunization. Interestingly, despite a low secondary ASC response, Ty21a was able to boost both humoral (anti-LPS systemic IgG and IgA) and CMI responses. Evidence of a CMI response was also observed for one of three volunteers given a cholera vaccine booster dose. The direct comparison of results with two attenuated live oral vaccine strains in human volunteers clearly showed that the capacity of the vaccine strain to colonize specific body compartments conditions the pattern of vaccine-induced immune responses.