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PubMed2006

Estimating vaccine effectiveness against laboratory-confirmed influenza using a sentinel physician network: results from the 2005-2006 season of dual A and B vaccine mismatch in Canada.

INTRODUCTION: We report a case-control design using a sentinel physician network to estimate vaccine effectiveness (VE) against laboratory-confirmed, medically attended influenza (LC-MAI) and provide results for the 2005-2006 season of dual A and B vaccine mismatch in Canada. METHODS: Participants were patients >or=5 years of age presenting with influenza-like illness (ILI) to a sentinel physician in British Columbia, Canada between November 1, 2005 and April 30, 2006. Cases were participants in whom influenza was identified; controls tested negative for influenza A and B by PCR, R-mix and culture. Isolates were characterized by gene-sequencing and hemagglutination-inhibition (HI) assays. Odds ratios (OR) for LC-MAI in vaccinated versus non-vaccinated persons were derived with adjustment for age and chronic conditions. VE was estimated as [1-OR (vaccinated/unvaccinated)]. RESULTS: The sample included 442 patient visits: median age was 26 years, 10% were >or=65 years, 15% had a chronic condition and 22% received the 2005-2006 trivalent inactivated influenza vaccine >or=2 weeks before ILI onset. Two hundred and six participants were positive for influenza; 107 (52%) had influenza A/H3N2 and 99 (48%) had influenza B/Victoria lineage. Gene sequencing identified mutations away from the vaccine strain at key antigenic binding sites of the hemagglutinin (HA) protein of H3N2 isolates; the neuraminidase (NA) protein was conserved. Based on HI assays, three-quarters of influenza A and all B isolates were mismatched to the 2005-2006 vaccine. Point estimates for VE against LC-MAI were in the range of 50 to 70% for both types of influenza. CONCLUSION: 2005-2006 was the third consecutive season of vaccine mismatch based on varying HA for the A/H3N2 component and the third also for the B component since 2001. Vaccine mismatch resulted in diminished VE but substantial cross-protection. More timely detection of drift variants through gene sequencing of isolates facilitates interpretation of VE results. Since it may be more antigenically conserved, the vaccine content and contribution of NA to overall VE should be further evaluated for both A and B components. Infrastructure for real-time epidemiologic assessment of vaccine performance is important annually and in preparation for a pandemic.

Adolescent↗

PubMedDate not supplied

Safety and immunogenicity of new cell-cultured smallpox vaccine compared with calf-lymph derived vaccine: a blind, single-centre, randomised controlled trial.

BACKGROUND: US government organisations have identified the need for a new smallpox vaccine to replenish limited stocks of the approved, calf-lymph derived vaccine, the manufacture of which is no longer acceptable. We aimed to compare the safety and immunogenicity of the new cell-cultured smallpox vaccine (CCSV) to that of the calf-lymph derived vaccine (as a positive control) in 350 healthy, adult volunteers. METHODS: We did a randomised controlled study at the University of Kentucky Medical Center. We randomised 150 vaccinia-naive volunteers, aged 18-30 years, and 100 vaccinia-non-naive people, aged 32-65 years, to equivalent doses of either CCSV or test vaccine (2.5x10(5) plaque-forming units) by 15 puncture scarification in double-blind fashion. Immunogenicity was assessed by pock formation (take rate), humoral immune response by plaque-reduction neutralisation titres, and cellular immune response by vaccinia-specific, interferon-gamma T-cell quantification, cytotoxicity, and T-cell proliferation response. A further 100 vaccine-naive individuals, aged 18-30 years, received one of five doses of CCSV (undiluted, diluted 1 in 5, 1 in 10, 1 in 25, and 1 in 50) in single-blind fashion. Routine laboratory assessments, physical examinations, and recording of adverse events were done to assess vaccine safety. The primary endpoints were safety and reactogenicity (take rate) of CCSV. FINDINGS: 349 (99.7%) of 350 volunteers developed pock lesions; one vaccinia-naive individual who received a 1 in 25 dilution of CCSV did not. The rate of adverse events related to vaccine and the extent of humoral and cellular immune responses did not differ between the vaccine groups in vaccinia-naive or non-naive people. CCSV was immunogenic in vaccine-naive volunteers at a dose 50 times lower than that approved for Dryvax. INTERPRETATION: CCSV seems to be a safe and immunogenic alternative to calf-lymph derived vaccine for both vaccinia-naive and non-naive people.

Adolescent↗

PubMed2001

The adjuvanted influenza vaccines with novel adjuvants: experience with the MF59-adjuvanted vaccine.

Elderly people and subjects with underlying chronic diseases are at increased risk for influenza and related complications. Conventional influenza vaccines provide only limited protection in the elderly population. In order to enhance the immune response to influenza vaccines, several adjuvants have been evaluated. Among these, an oil in water adjuvant emulsion containing squalene, MF59, has been combined with subunit influenza antigens and tested in clinical trials in comparison with non-adjuvanted conventional vaccines. Data from a clinical database of over 10000 elderly subjects immunised with this adjuvanted vaccine (Fluad, Chiron Vaccines, Siena, Italy) demonstrate that, although common postimmunisation reactions are more frequent in recipients of the adjuvanted vaccine, this vaccine is well tolerated, also after re-immunisation in subsequent influenza seasons. Immunogenicity analyses demonstrate a consistently higher immune response with statistically significant increases of postimmunisation geometric mean titres, and of seroconversion and seroprotection rates compared to non-adjuvanted subunit and split influenza vaccines, particularly for the A/H3N2 and the B strains. The higher immunogenicity profile of the MF59-adjuvanted vaccine is maintained also after subsequent immunisations. An even higher adjuvant effect was shown in subjects with low pre-immunisation titre and in those affected by chronic underlying diseases. In conclusion, the addition of MF59 to subunit influenza vaccines enhances significantly the immune response in elderly subjects without causing clinically important changes in the safety profile of the influenza vaccine.

Adjuvants, Immunologic↗

PubMed2001

Vaccination of mice with a cocktail DNA vaccine induces a Th1-type immune response and partial protection against Schistosoma japonicum infection.

Several defined vaccine candidate antigens of Schistosoma japonicum have shown promise in large animal vaccination experiments. However, vaccination of mice in the laboratory with either single recombinant antigens or DNA encoding forms of the individual antigens has so far failed to induce significant protection against S. japonicum cercarial challenge infection as judged by worm reduction, although specific antibodies were generated. This is in contrast to the results achieved using radiation-attenuated vaccines which are highly protective. Even in large animal vaccination experiments, the protection levels obtained with single defined antigens were far below those achieved using the attenuated vaccines. One possible interpretation is that the immune responses induced by single antigen vaccination may not be strong enough to combat the challenging infection. We, therefore, carried out mouse vaccination experiments using a cocktail DNA vaccine comprising four DNA plasmids encoding four different S. japonicum antigens, Sj62, Sj28, Sj23 and Sj14-3-3, respectively. We, also investigated whether co-injection of the mouse IL-12 encoding plasmid with the cocktail DNA vaccine was able to enhance the Th1 responses and hence the protective immunity. Three intramuscular injections of the cocktail DNA vaccine induced a significant Th1-type cellular response with high level of IFN-gamma production by splenocytes upon in vitro stimulation with recombinant antigens. Importantly, significant IgG antibody responses were also induced against crude worm antigens. In two out of three experiments, significant resistance (34-37 and 44-45%, respectively) was demonstrated while another experiment did not show any protection against S. japonicum cercarial challenge infection. Co-injection of the IL-12 encoding DNA did not further enhance these responses, nor the level of resistance, compared with the cocktail DNA alone.

Animals↗

PubMed2002

Immune response of HLA DQ2 positive subjects, vaccinated with HBsAg/AS04, a hepatitis B vaccine with a novel adjuvant.

About 5-10% of the general adult population respond inadequately to hepatitis B vaccination. The histocompatibility leucocyte antigen (HLA) DQ2, DR3 and DR7 phenotypes have been linked with non-responsiveness to hepatitis B vaccination. A first part of our study determined the prevalence of the HLA DQ2 allele in a healthy population, aged 15-50 years. We found 35% of our study population (n=1008) positive for the HLA DQ2 allele. Positive subjects for HLA DQ2 were subsequently invited to participate in a trial and were to be given either the HBsAg/AS04 hepatitis B vaccine or a licensed hepatitis B vaccine (Engerix-B).(1) Both contained 20 microg of recombinant HBsAg. The HBsAg/AS04 vaccine was administered on a 0 and 6 months schedule whilst the comparator vaccine was given according to the standard 0, 1 and 6 months schedule. The experimental vaccine was formulated on a novel adjuvant containing 3' deacylated monophosphoryl lipid A (3D-MPL) and alum. A total of 230 subjects were enrolled into the vaccination study. At month 7, 99% of the subjects had a protective titre (>or=10mIU/ml) with a geometric mean titre (GMT) of 6613mIU/ml in the group receiving HBsAg/AS04 versus 97% seroprotected with a GMT of 2315mIU/ml in the other group. Both vaccines, with their respective schedule, give very high seroprotection rates (>96%). Our data suggest that HLA DQ2 positivity is not a good marker for non- or poor-responsiveness. The HBsAg/AS04 vaccine was more reactogenic mainly because of an increased local reactogenicity. Both vaccines, especially HBsAg/AS04, are highly immunogenic and well tolerated by the study subjects.

Adolescent↗

PubMed2003

The vaccine data link in Nha Trang, Vietnam: a progress report on the implementation of a database to detect adverse events related to vaccinations.

Real, perceived and unknown adverse events secondary to vaccinations are a source of concern for care providers of children. In the USA large linked databases have provided helpful information regarding the safety of vaccines. Very little prospectively collected data on vaccine safety is available from resource poor countries, but safety concerns may be even more relevant in such settings. Vaccine manufacturers do not have to pass the same rigorous safety standards as vaccine manufacturers in rich countries. Vaccines, which protect against cholera, Japanese encephalitis, rabies or typhoid fever are predominantly used in resource poor, tropical countries and frequently do not undergo vigorous post marketing surveillance. New vaccines specifically suited for resource poor countries are sometimes marketed without the scrutiny of vigilant, independent regulatory authorities. We describe here the design and implementation of a large linked database for a semi-rural province in central Vietnam. The design overcomes several problems inherent in data bases of medical events and vaccinations in developing countries. Assigning a permanent identification (ID) number to each resident avoids the ambiguities of ID numbers based on the address. The distribution and use of medical identification cards with a permanent ID number assists in the unambiguous identification of vaccinees and patients. Medical records of all admissions are coded according to International Classification of Diseases (ICD-10) and transcribed into a computer system. Because these processes are novel the data collected by the study will be validated. Project staff will check records on vaccinations and hospital admissions through household visits at regular intervals. Data describing vaccinations and medical events are linked to the data collected by the project staff in a computer system. Based on the validation of the data we hope to optimize this model. Once we find the model working it is planned export this vaccine data safety link to other settings of similar economic status.

Database Management Systems↗

PubMed1996

Immune response to tissue culture rabies vaccine in subjects who had previous postexposure treatment with Semple or suckling mouse brain vaccine.

Nerve tissue derived Semple and suckling mouse brain rabies vaccines are still widely used. Patients who experience a new rabies exposure and who were given such vaccines decades earlier are not uncommon in rabies endemic countries. The World Health Organization recommends that persons who have had a previous course of a potent tissue or avian culture rabies vaccine and are reexposed, be given booster infections on days 0 and 3 without rabies immune globulin. Persons who have had previous pre- or postexposure vaccination with a vaccine of unproven potency, should receive a full course of tissue or avian cell vaccine and immune globulin in the event of a new exposure. This study evaluated the immune response in 98 Thai patients who gave a history of rabies postexposure treatment with Semple or suckling mouse brain vaccines 10-50 years previously. The majority (81) had an anamnestic response and developed neutralizing antibodies that were above the recommended minimal acceptable level (0.5 IU ml-1) on day 7. This suggests that they still had immunological memory. A minority of 18% had antibody titers below this level on day 7. However, they all developed titers above 0.5 IU ml-1 on days 14 and 30. Failure to have an accelerated response to revaccination by day 7 did not appear to be related to age or time elapsed since previous nerve tissue derived vaccine administration. It was not possible to predict which subject will or will not have an acceptable level of antibody before day 14. Rabies exposed patients who give a prior history of vaccination with an unknown or nerve tissue derived vaccine should therefore be treated as if they had never been vaccinated.

Adolescent↗

PubMed1992

Rabies vaccine standardization: International Collaborative Study for the Characterization of the fifth International Standard for Rabies Vaccine.

A collaborative study was carried out to establish a replacement for the International Standard for Rabies Vaccine, the stocks of which are exhausted. Three rabies vaccines for human use derived from different rabies virus strains and prepared on different cell culture substrates were compared with the International Standard for Rabies Vaccine using in vivo and in vitro assay methods in a collaborative study involving 14 participants. The proposed fifth International Standard (PISRAV) which was derived from the same virus strain as the present international standard preparation, the Pitman Moore (PM) strain, was found to be approximately twice as potent relative to the International Standard in immunogenicity assays as in antigenicity assays. On the other hand another vaccine, derived from the LEP strain, was considerably more potent in antigenicity assays than in immunogenicity assays. The glycoprotein of the proposed replacement standard measured in antigenicity assays appeared to be stable at +37 degrees C for 245 days, whereas the immunogenicity of the proposed replacement vaccine was sensitive to this heat treatment and the vaccine lost 66% of its immunogenic potency. The results of this study indicate that the NIH protection test should continue to form the primary basis for potency assay of rabies vaccine as glycoprotein content does not appear to correlate with immunogenic potency for different types of vaccine. The vaccine coded PISRAV has been established as the fifth International Standard for Rabies Vaccine and a potency of 16 International Units of Rabies Vaccine (based on the immunogenicity assays) assigned to the contents of each ampoule. Each ampoule has also been assigned a unitage of 10 IU of PM Rabies Virus Glycoprotein and 135 IU of PM Rabies Virus Ribonucleoprotein.

Animals↗

PubMed1970

Vaccination against Hong Kong influenza in Britain, 1968-9. A report to the Medical Research Council Committee on Influenza and other Respiratory Virus Vaccines.

Studies of the effect of Hong Kong (HK) influenza vaccine were made in adults and children in Great Britain during 1968 and 1969. The vaccines were administered intramuscularly and also by intranasal spray. The serum antibody response was studied in 284 subjects. Most developed rising titres to vaccine given intramuscularly and few to vaccine given intranasally. Deoxycholate-split vaccine was as potent as conventional whole virus vaccine. Antibody titres were maintained for months. Over 4000 subjects in factories, offices and schools were observed during the epidemic. The incidence of disease was not significantly reduced by either form of vaccination. A survey was made of epidemics in boarding schools in which some of the pupils had been vaccinated, in six with commercial polyvalent vaccine and in five with HK; there was a lower incidence of influenza in two schools vaccinated 2 or 4 weeks earlier with HK vaccine.

Adult↗

PubMed2001

Opsonophagocytic activity against Streptococcus pneumoniae type 19F in allogeneic BMT recipients before and after vaccination with pneumococcal polysaccharide vaccine.

Opsonophagocytic activity (OPA) of pneumococcal polysaccharide (Pnc PS) antibodies in vitro, a measure of antibody functional activity, usually correlates with specific IgG antibody concentrations measured by an EIA method. In order to investigate the functional activity of specific Pnc PS antibodies, we determined IgG antibodies to Pnc PS type 19F by an EIA method and OPA against Pnc type 19F by a killing assay in a randomized study, where 23 adult allogeneic BMT recipients were vaccinated with Pnc PS vaccine at 8 months (early group) and 21 recipients at 20 months (late group) after transplantation. Serum samples drawn before BMT, before vaccination, and at 1 and 16 months after vaccination were available from 27, 35, 34 and 30 patients, respectively. The geometric mean anti-Pnc 19F concentrations were 4.3, 1.3, 1.6 and 1.3 microg/ml in the early group and 3.8, 0.9, 0.6 and 0.6 microg/ml in the late group before transplantation, before vaccination, and at 1 and 16 months after vaccination, respectively. OPA (titre > or = 8) was found in 10/27, 5/35, 5/34 and 6/30 patients before BMT, before vaccination, and at 1 and 16 months after vaccination, respectively. The specific IgG antibody concentration and OPA correlated with each other before BMT, and in the early group patients before and at 1 month after vaccination. The results demonstrate that after Pnc PS vaccination allogeneic BMT recipients have antibodies with low functional activity to a Pnc PS antigen associated with low specific IgG responses. There is a need to study new Pnc conjugate vaccines in multi-dose schedules for their capacity to elicit higher specific antibody concentrations with high OPA in BMT recipients.

Adult↗

PubMed2001

Tetanus immunization in pregnant women: evaluation of maternal tetanus vaccination status and factors affecting rate of vaccination coverage.

The objectives of this study were to determine the tetanus vaccination status for pregnant women, and to examine the effects of various factors on tetanus toxoid (TT) vaccination coverage during pregnancy in reproductive-age women. Four-hundred and ninety-three postpartum women who had live births at a hospital in Ankara were interviewed and information was collected on the mothers' sociodemographic characteristics, TT vaccination history, and prenatal care during the pregnancy studied. The rates for no vaccination, one-dose vaccination, and two-dose vaccination were 53.3%, 18.9%, and 27.8%, respectively. The vaccinated women (with at least one dose) were significantly younger, of lower parity, and had attended more prenatal care visits than the unvaccinated women. Of the women who attended at least one prenatal care check-up, only about half were vaccinated. Significantly more rural women were vaccinated against tetanus than urban women. Current vaccination rates with TT during pregnancy were found to be well below universal levels. Turkey needs to launch effective mass media campaigns that target urban and suburban populations, and inform and motivate women to request vaccination against tetanus.

Adult↗

PubMed2006

Subjective and objective risk as predictors of influenza vaccination during the vaccine shortage of 2004-2005.

BACKGROUND: We aimed to identify the role of objective risk status and subjective risk beliefs in influenza vaccination decisions during the recent rationing of influenza vaccine. METHOD: A random sample of 300 Americans, obtained through random-digit dialing, was interviewed regarding influenza vaccination practices and beliefs in September 2004 and again in March 2005. RESULTS: One-half of individuals at high risk of influenza did not know that they were at high risk and, therefore, were not vaccinated. Respondents at high objective risk were more likely to report having been vaccinated than respondents who were not at high objective risk (36% vs. 6%, respectively; odds ratio, 8.31; 95% confidence interval, 3.65-18.88). However, a more powerful predictor of self-reported vaccination was subjective risk (64% vs. 7%, respectively; odds ratio, 24.02; 95% confidence interval, 12.18-48.09). Subjective risk fully mediated the relationship between objective risk and vaccination. Other predictors of vaccination included physician recommendation, habit, prior vaccination intention, belief that the influenza vaccine is safe and effective, perceived likelihood of getting influenza, and trait neuroticism. CONCLUSION: Health communication efforts must be more effective in persuading adults with chronic illness and individuals in contact with persons at risk that they should be vaccinated against influenza.

Adolescent↗

PubMed2000

Vaccination with a mixed vaccine of autogenous and allogeneic breast cancer cells and tumor associated antigens CA15-3, CEA and CA125--results in immune and clinical responses in breast cancer patients.

In breast cancer there is often overexpression of the breast cancer antigen CA15-3, the carcinoembryonic antigen (CEA) and the ovarian cancer antigen CA125, which makes them potential target antigens for immunotherapy. In this study, we used a multi-antigen vaccine, which included the following antigens: autologous breast cancer cells (AUTOC), allogeneic breast cancer MCF-7 cells (ALLOC), and the tumor associated antigens CA15-3, CEA and CA125, plus low doses of granulocyte/macrophage-colony-stimulating factor (GM-CSF) and interleukin 2 (IL-2). Forty-two breast cancer patients received weekly subcutaneous vaccination at the 1st, 2nd, 3rd, 7th, 11th and 15th weeks. Their lymphocyte proliferative responses to AUTOC, ALLOC, CA15-3, CEA and CA125 were tested in lymphocyte blastogenesis assays (LBA) before and after vaccination. The disease stage and serum CA15-3, CEA and CA125 concentrations were also determined pre- and post-vaccination. We found that the vaccine was safe, and the only major side effects were swelling at the site of injection, muscle pain, and weakness or fatigue. The vaccine induced a significant increase in post-vaccination lymphocyte proliferative responses to AUTOC, CA15-3, CEA and CA125 but not ALLOC, compared to pre-vaccination (p < 0.05, p < 0.01, p < 0.05, p < 0.01 and p > 0.05, respectively, a paired t Test). Computed tomography (CT), ultrasound or bone scan showed evidence of disease improvement in 2 (12%) patients after vaccination. Hepatic metastases were reduced in size and number and some actually disappeared one patient. Metastatic disease in the L5 vertebra and the skull decreased in size and some osteolytic sites completely healed in a second patient. In addition, 7 patients (44%) had stable disease and 7 patients (44%) had disease progression. We did not find vaccination significantly reduced serum tumor markers CA15-3, CEA and CA125 of these breast cancer patients. These results suggest that the vaccine mixture of autologous and allogeneic breast cancer cells and tumor associated antigens plus GM-CSF and IL-2 can be administered safely to breast cancer patients and there is evidence for improved immunity and clinical efficacy.

Adult↗

PubMed2001

Rotavirus vaccine and intussusception: how much risk will parents in the United States accept to obtain vaccine benefits?

Postlicensure surveillance of a newly licensed rotavirus vaccine suggested an increased risk of intussusception. Little was known about the amount of risk parents would tolerate to obtain the vaccine's benefits or the extent to which risk would reduce the price parents would pay for the vaccine. Parents of infants aged 12 months or younger were asked to accept or reject two hypothetical vaccines associated with varying degrees of risk. Parents chose from a list the amount they would pay for two additional hypothetical vaccines, with and without a risk of intussuception. The authors conducted face-to-face surveys in September 1999 among a convenience sample of parents in three US cities. Of 405 eligible parents, 260 (64%) participated. To achieve a 90% acceptance rate, the vaccine could be associated with no more than 1,794 (95% confidence interval: 1,551, 2,025) cases of intussusception in a fully vaccinated, national cohort of infants. The median willingness to pay for three vaccine doses, when vaccination was associated with 1,400 cases of intussusception, was $36 (95% confidence interval: $28, $46) compared with $110 (95% confidence interval: $96, $126) for the risk-free vaccine. The most important aspect of this study may be the methodology to assess how parents balance the benefits and risks of childhood vaccines.

Adult↗

PubMed1997

Protection against haemorrhagic septicaemia induced by vaccination of buffalo calves with an improved oil adjuvant vaccine.

An experimental oil adjuvant vaccine was developed against haemorrhagic septicaemia, a disease of cattle and buffalo caused by Pasteurella multocida serotype B and E. Mineral oil, Mercol 52, was used as adjuvant together with Span 85 and Tween 85 as emulsifiers. The vaccine was evaluated by single dose intramuscular immunisation of 1-2 year old buffalo calves. IgG and IgM class antibodies were determined by ELISA. The group of animals immunised with the experimental oil adjuvant vaccine showed a high titre of the IgG class of antibodies measured at 300 days post vaccination. To compare the protective efficacy of the vaccine with the commonly used broth bacterin, another group of buffalo calves was immunised by broth bacterin. This group showed a low level of IgG antibodies. Protection was assessed by challenge with 10(9) viable bacteria of P. multocida type B:2,5 administered subcutaneously, 250 days post vaccination. Animals vaccinated with the experimental oil adjuvant vaccine were fully protected. The other groups of animals, vaccinated with broth bacterin or used as control (non-vaccinated), developed symptoms of haemorrhagic septicaemia. A strong relationship between IgG but not IgM class antibody level and resistance to challenge was observed. The experiment demonstrated that the experimental oil adjuvant vaccine was superior to broth bacterin in providing protection against experimental haemorrhagic septicaemia in young buffalo calves beyond 250 days.

Adjuvants, Immunologic↗

PubMed1997

The HSD-hCG vaccine prevents pregnancy in women: feasibility study of a reversible safe contraceptive vaccine.

PROBLEM: To develop a vaccine for reversible control of fertility in women. MATERIALS AND PROTOCOLS: Purified beta subunit of hCG annealed to purified alpha subunit of ovine LH linked chemically to tetanus toxoid (TT) and diphtheria (DT); vaccine employed at 300 micrograms gonadotropin equivalent per injection adsorbed on alhydrogel with 1 mg SPLPS added in the first injection; Phase I safety trials in 47 women with elective tubal ligation; Phase II efficacy studies in 148 proven fertile women (2 children), sexually active, desirous of family planning using IUD; IUD removed when anti-hCG titres exceed 50 ng/ml hCG bioneutralization capacity; boosters given to maintain above threshold antibody levels; post coital tests conducted in 8 volunteers; sera of protected women analysed for immuno-determinants recognized by competitive enzyme immunoassays employing a panel of monoclonal antibodies and by direct binding to synthetic peptides; recombinant vaccines expressing beta hCG as a secreted product or as a fused protein anchored on membrane. RESULTS: Immunization was well tolerated with no significant changes in endocrine, metabolic and hematological indices. Normal ovulatory cycles were maintained as indicated by menstrual regulation. The vaccine was highly effective in preventing pregnancy (1 pregnancy in 1224 cycles ) at and above antibody titres of 50 ng/ml. Antibodies declined in course of time in absence of boosters, with conceptions occurring below 35 ng/ml titres indicating regain of fertility. Ability of antibodies to prevent pregnancy was confirmed by post coital tests. High avidity (10(10) M-1) and other characteristics of antibodies generated by the vaccine are described and compared with those induced by two other hCG vaccines having undergone Phase I trials. The antibody response of the HSD vaccine in humans is characterized predominantly to an epitope recognized by the monoclonals 206 and P3W80. The antibodies had low or no reactivity with the carboxy terminal peptide and 38-57 region peptide. Live recombinant vaccines expressing beta hCG as a membrane anchored peptide generated antibody response to hCG in all animals following a single injection. CONCLUSIONS: Reversible fertility control is feasible with the HSD-hCG vaccine without impairment of ovulation or disturbance of menstrual regularity. Suggestions have been made for further optimization of the vaccine, which include replacement of TT and DT by a panel of T non B determinants communicating with the entire MHC spectrum and development of recombinant vaccine expressing beta hCG along with membrane anchored carrier.

Animals↗

PubMed1995

Defining surrogate serologic tests with respect to predicting protective vaccine efficacy: pertussis vaccination.

The first efficacy trial of pertussis vaccines with defined purified antigens failed to demonstrate a serologic correlate of protection, although both tested vaccines were shown to give significant protection against typical whooping cough. The antibody response to pertussis toxoid was dose dependent. A lower anti-PT response in the two-component vaccine, containing one-half the amount of PT in the one-component vaccine, seemed to be compensated by a significant anti-FHA response, since both vaccines conferred similar protection against typical illness. However, the immunologic mechanisms whereby protection is conferred remain unclear. At present antibody responses to the antigens included in the first tested vaccines could be used as pseudoindicators of protection. The group of vaccinated infants who were protected did differ in their antibody profile as compared to unvaccinated infants. Tentatively, candidate vaccines should elicit no less antibody responses to PT and FHA as those elicited by the above one- and two-component vaccines, respectively. The response to other antigens such as pertactin and fimbriae cannot be related to protection at present. Ongoing efficacy trials of a number of pertussis vaccines of varying composition may or may not provide immunological correlates of protection against pertussis. The trials ought to be subjected to a preplanned, independent (meta)analysis with defined end points to increase the understanding of the contribution of various antigens to the protective efficacy of pertussis vaccines.

Antibodies, Bacterial↗

PubMed2004

Single intranasal mucosal Mycobacterium bovis BCG vaccination confers improved protection compared to subcutaneous vaccination against pulmonary tuberculosis.

Whether the intranasal (i.n.) route of Mycobacterium bovis BCG vaccination provides better protection against pulmonary tuberculosis than subcutaneous (s.c.) vaccination remains an incompletely solved issue. In the present study, we compared both immune responses and protection elicited by single BCG vaccinations via the i.n. or s.c. route in BALB/c mice. While both i.n. and s.c. vaccination triggered comparable levels of primary immune activation in the spleen and draining lymph nodes, i.n. vaccination led to a greater antigen-specific gamma interferon recall response in splenocytes than s.c. vaccination upon secondary respiratory mycobacterial challenge, accompanied by an increased frequency of antigen-specific lymphocytes. There was also a quicker cellular response in the lungs of i.n. vaccinated mice upon mycobacterial challenge. Mice vaccinated i.n. were found to be much better protected, particularly in the lung, than s.c. vaccinated counterparts against pulmonary tuberculosis at both 3 and 6 months postvaccination. These results suggest that the i.n. route of vaccination improves the protective effect of the current BCG vaccine.

Administration, Intranasal↗