Next generation inactivated polio vaccine manufacturing to support post polio-eradication biosafety goals

Worldwide efforts to eradicate polio caused a tipping point in polio vaccination strategies. A switch from the oral polio vaccine, which can cause circulating and virulent vaccine derived polioviruses, to inactivated polio vaccines (IPV) is scheduled. Moreover, a manufacturing process, using attenuated virus strains instead of wild-type polioviruses, is demanded to enhance worldwide production of IPV, especially in low- and middle income countries. Therefore, development of an IPV from attenuated (Sabin) poliovirus strains (sIPV) was pursued. Starting from the current IPV production process based on wild type Salk strains, adaptations, such as lower virus cultivation temperature, were implemented. sIPV was produced at industrial scale followed by formulation of both plain and aluminium adjuvanted sIPV. The final products met the quality criteria, were immunogenic in rats, showed no toxicity in rabbits and could be released for testing in the clinic. Concluding, sIPV was developed to manufacturing scale. The technology can be transferred worldwide to support post polio-eradication biosafety goals.

Systematic review of mucosal immunity induced by oral and inactivated poliovirus vaccines against virus shedding following oral poliovirus challenge

Inactivated poliovirus vaccine (IPV) may be used in mass vaccination campaigns during the final stages of polio eradication. It is also likely to be adopted by many countries following the coordinated global cessation of vaccination with oral poliovirus vaccine (OPV) after eradication. The success of IPV in the control of poliomyelitis outbreaks will depend on the degree of nasopharyngeal and intestinal mucosal immunity induced against poliovirus infection. We performed a systematic review of studies published through May 2011 that recorded the prevalence of poliovirus shedding in stool samples or nasopharyngeal secretions collected 5-30 days after a "challenge" dose of OPV. Studies were combined in a meta-analysis of the odds of shedding among children vaccinated according to IPV, OPV, and combination schedules. We identified 31 studies of shedding in stool and four in nasopharyngeal samples that met the inclusion criteria. Individuals vaccinated with OPV were protected against infection and shedding of poliovirus in stool samples collected after challenge compared with unvaccinated individuals (summary odds ratio [OR] for shedding 0.13 (95% confidence interval [CI] 0.08-0.24)). In contrast, IPV provided no protection against shedding compared with unvaccinated individuals (summary OR 0.81 [95% CI 0.59-1.11]) or when given in addition to OPV, compared with individuals given OPV alone (summary OR 1.14 [95% CI 0.82-1.58]). There were insufficient studies of nasopharyngeal shedding to draw a conclusion. IPV does not induce sufficient intestinal mucosal immunity to reduce the prevalence of fecal poliovirus shedding after challenge, although there was some evidence that it can reduce the quantity of virus shed. The impact of IPV on poliovirus transmission in countries where fecal-oral spread is common is unknown but is likely to be limited compared with OPV.

Inactivated poliovirus vaccine and the final stages of poliovirus eradication

The use of the inactivated poliovirus vaccine (IPV) will increase before and probably also after the global eradication of the wild type poliovirus. Before eradication, the switch from the use of oral poliovirus vaccine (OPV) to IPV has been due to the better safety record of IPV. Introduction of IPV in the regular immunisation schedules is made easier by the development of several combination vaccines, including IPV. Maternal antibodies and young age, often considered problematic for early initiation of IPV schedules, did not compromise optimal maintenance of seropositivity during infancy or long-term persisting antibody levels in our studies. OPV-derived, potentially pathogenic and transmissible poliovirus strains, excreted by some individuals for years, may present a problem for a blunt stopping of all polio immunisations after eradication. Our recent results suggest that locally excreted IgA might have a role in the elimination of poliovirus infection in the intestinal tissues.

Oral poliomyelitis vaccine: time to change?

For 3 decades, vaccination against poliomyelitis has rested mainly on the use of the oral attenuated vaccine (OPV). In countries where wild type poliomyelitis has been successfully controlled by OPV, the rare cases of poliomyelitis that can still be identified occur in vaccinees or their contacts and are caused by vaccine related strains. Over years, data indicating that the inactivated vaccine (IPV) also has the potential to control poliomyelitis and that there are no known risks associated with the use of this vaccine have accumulated. The reasons for changes in vaccine policy in industrialised countries and the situation of the global effort of poliomyelitis immunisation are described. Some of the issues and challenges for the future are reviewed.

Mutual interactions between DTaP-IPV and Haemophilus influenzae type b (Hib)-conjugated vaccines in laboratory animal models

Potency and/or immunogenicity of three different Haemophilus influenzae type b-conjugated vaccines (Hib) and a DTaP-IPV vaccine alone, and their mutual interactions in DTaP-IPV-Hib combination was tested. In a mouse model, only combination of Act-Hib, in which tetanus toxoid (TT) was as active as non-conjugated TT, significantly increased the immunogenicity and potency of TT component of DTaP-IPV vaccine. Also, only combination of Hib-TITER, in which CRM197 was used as the carrier with DTaP-IPV, increased the potency of diphtheria toxoid (DT) component of DTaP-IPV vaccine significantly. It shows that the additive effect of tested Hib vaccines on immunogenicity and/or potency of TT and DT was mostly due to the existence of TT and CRM197, respectively, as the carrier in the mentioned Hib vaccines. No difference was shown in inoculation of DTaP-IPV and Hib conjugated vaccines in the same syringe or at separate sites. DTaP-IPV had dual effects on anti-Hib capsular polysaccharide (HibCP) responses to Hib vaccines in the mouse model. This duality was probably related to the carrier B-cell epitopes activity of Hib conjugated vaccines. The immunogenicity of TT component of Act-Hib and Amvax Hib-TT in the guinea pig model was shown and combination of mentioned Hib vaccines with DTaP-IPV, remarkably increased anti-TT antibody responses to the TT component of DTaP-IPV vaccine. These confirmed our results in the mouse model. Using two different protocols to evaluate the guinea pig model for induction of anti-HibCP immunity showed that a "long interval" protocol does not have any advantage over the "short interval" protocol. Also, combination of DTaP-IPV with Hib vaccines did not have any noticeable effect on anti-HibCP antibodies in the guinea pig model. Taken together, our observations in laboratory animal models may facilitate a better understanding of the mutual interactions between the different antigen components of a combined vaccine such as DTaP-IPV-Hib vaccine.

Immune response to a booster dose of enhanced potency inactivated polio vaccine administered in association with HBV vaccine in adolescents

The immunogenicity and reactogenicity of a booster dose of enhanced potency inactivated polio vaccine (EIPV) were evaluated in 492 healthy 12 year old adolescents. The booster was administered at the same time as the HBV vaccine compulsory in Italy at this age. Blood samples and questionnaires on reactogenicity were collected over 9 months. Analysis of pre-vaccination immunity showed that 97.4% of the subjects were protected against all polio types, 1.9% were negative for two polio types and 0.6% for one. After vaccination 98.4% of the vaccinees showed a significant increase ( > or = 4 times) of antibody titre; the geometric mean titres (GMT) were markedly higher than before vaccination, particularly for poliovirus type 3. The polio booster dose did not affect HBV vaccination. An anti-HBs response > 10 mIU ml-1. (GMT = 2951 mIU ml-1) was observed in 781 (98.6%) of 792 vaccinees (492 given EIPV+HBV and 300 given only HBV) 9 months later. Only mild local and rare general reactions were noted for both the vaccines studied. These data confirm the suitability and efficacy of an EIPV booster dose and HBV vaccination in adolescents.

Whole-body protein turnover and hepatic protein synthesis are increased by vaccination in man

1. The ability of diphtheria-tetanus-poliomyelitis-typhoid vaccination to induce modifications in protein metabolism was investigated in post-absorptive healthy humans. 2. Seven subjects were studied before and 2 days after vaccination. They underwent an intravenous primed constant infusion of L-[1-13C]leucine for 4h. Plasma protein concentrations, whole-body amino acid fluxes and acute-phase protein synthesis were determined. 3. Plasma concentrations of fibrinogen, alpha 1-acid glycoprotein, haptoglobin and alpha 1-antitrypsin were significantly elevated 2 days after vaccination (P < 0.05). Leucine oxidation was unaffected but whole-body protein synthesis and breakdown were both increased (P < 0.05), by 25 and 16% respectively, in subjects who had an elevated body temperature (n = 5). Albumin synthesis was unchanged, but hepatic synthesis of fibrinogen was 56% higher after vaccination. 4. The present investigation indicates that diphtheria-tetanus-poliomyelitis-typhoid vaccination could induce a sustained acute-phase reaction. Moreover, protein metabolism appeared to be extremely sensitive to a mild stress since leucine kinetics and fibrinogen synthesis were affected. Therefore, diphtheria-tetanus-poliomyelitis-typhoid vaccination might represent an attractive model for studying the inflammatory process in humans.

Deterministic models for the eradication of poliomyelitis: vaccination with the inactivated (IPV) and attenuated (OPV) polio virus vaccine

Currently two polio vaccines, IPV and OPV, are in use which differ markedly in their epidemiological parameters. A simple epidemiological model in terms of ordinary differential equations is proposed to study the effects of vaccination campaigns using these vaccines. The numbers of interest are the reproduction number of the disease in the presence of vaccination and the critical vaccination coverage necessary to prevent an outbreak. For these numbers explicit representations are determined which can be used in comparing different vaccination strategies.

Antibody response and viral excretion after live polio vaccine or a combined schedule of live and inactivated polio vaccines

A randomized controlled trial was performed in infants undergoing routine immunization in North Hertfordshire. Ninety-six children received a single dose of inactivated polio vaccine, followed by two doses of live attenuated oral polio vaccine and 97 children received three doses of live attenuated oral polio vaccine at 2, 3 and 4 months of age. Blood samples were taken by study nurses 6 weeks after vaccination and stool samples were collected by parents weekly for 4 weeks after each dose of vaccine. Follow-up was completed for 92 of 96 (96%) children in the combined schedule group and 92 of 97 (95%) in the control group. After vaccination the proportions of children with detectable antibody to poliovirus serotypes 1, 2 and 3 were high and similar between groups and geometric mean titers (95% confidence interval) to poliovirus types 1, 2 and 3 were 264 (200 to 347), 375 (311 to 450) and 189 (144 to 250) in the combined schedule group and 369 (290 to 469), 401 (321 to 498) and 206 (145 to 293) in the live vaccine group, respectively. The only significant difference between groups in rates of viral excretion was observed after the second dose of live attenuated oral polio vaccine, when excretion of type 3 poliovirus was reduced in those children who had received prior inactivated polio vaccine (P = 0.05). This study suggests that, compared with the current schedule, a combined schedule of inactivated and live poliovaccines is likely to produce equivalent individual protection against poliomyelitis and is unlikely to substantially alter circulation of poliovirus in the community.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of prophylaxis with chloroquine and proguanil on delayed-type hypersensitivity and antibody production following vaccination with diphtheria, tetanus, polio, and pneumococcal vaccines

In vitro studies have shown that anti-malarial drugs suppress immunity. In this study, the effects of chloroquine and proguanil (Paludrine) on the cellular and humoral immune system were measured by two in vivo methods: 1) cell-mediated immunity (delayed cutaneous hypersensitivity) i.e., skin tests with seven delayed-type common antigens (Multitest) and 2) humoral immunity by measurement of specific antibody response to vaccination. Sixty healthy young individuals were randomized into four groups and given 1) no treatment (controls), 2) chloroquine diphosphate (500 mg/week), 3) chloroquine diphosphate (1,000 mg/week), or 4) proguanil hydrochloride (200 mg/day) for six weeks. Skin testing was performed on days 0 and 28. Vaccinations with diphtheria, tetanus, polio, and pneumococcal polysaccharide antigen vaccines were performed on day 28, and the presence of specific antibodies was determined on days 0, 28, and 42. The skin tests induced a significant increase in skin reactive areas from day 0 to day 28 in all groups. Furthermore, the skin test induced an increase in the level of specific IgG for diphtheria and tetanus, but had no effect on antibodies to antigens not included in the skin test. The results showed that there were no significant differences among the four groups regarding skin test areas and increases in antibody titers following vaccination. Therefore, it is concluded that in healthy persons, six weeks intake of chloroquine, even in double doses, or proguanil in chemoprophylactic dosages, does not induce any detectable suppression of delayed-type hypersensitivity or vaccination responses to diphtheria, tetanus, polio, or pneumococcal polysaccharide antigens.

Effect of inactivated viral vaccines (human) on frequency of micronuclei in bone marrow erythrocytes of mice

Cytogenetic effects of the two inactivated viral vaccines (polio and antirabies) were studied in adult male mice by the micronucleus test. Polio salk vaccine did not induce micronuclei formation at both human (0.5 ml) and 1/5th human doses. Antirabies vaccine induced micronuclei in poly and total erythrocytes only at human dose of 2 ml. Beta-propiolactone (BPL) induced micronuclei at higher dose of 5.7 mg, but not at 0.57 mg (approximate concentration present in 2 ml of rabies vaccine). The P/N ratio was not affected in vaccinated and BPL inoculated animals. Antirabies vaccine induced micronuclei percentage was more than the BPL value.

Antipolio prophylaxis of immunocompromised children during a nationwide oral poliovaccine campaign

A nationwide vaccination campaign with oral poliovirus vaccine was organized in Finland in 1985 to halt an outbreak of poliomyelitis. Immunocompromised persons and their household contacts were excluded from the oral poliovirus vaccine target group and given instead a dose of inactivated poliovirus vaccine. This gave us an opportunity to determine whether immunocompromised persons are protected from poliomyelitis during an outbreak and oral poliovirus campaign. Fourteen children, ages 3 to 17 years, with leukemia were given a booster dose of a novel high antigen content, trivalent inactivated poliovirus vaccine. All but two responded by an at least 4-fold increase in serum-neutralizing antibodies to at least one poliovirus serotype. These results indicate that children with acute lymphocytic leukemia in remission respond well to a booster dose of inactivated poliovirus vaccine. Antibody concentrations to the uncommon local epidemic strain of type 3 poliovirus remained, however, relatively low in most patients (median, 1:6) suggesting relatively impaired heterologous response to vaccination. Possible spread of live vaccine viruses to the inactivated poliovirus-vaccinated children and their close contacts was evaluated by examining weekly fecal specimens from 20 children and their 19 regular adult contacts for cytopathic viruses. No polioviruses were isolated from 224 specimens examined, indicating that this high risk population was well-protected from unintended exposure to live polioviruses.

Proportions of immunoglobulin isotypes in paralytic poliomyelitis and after vaccination

Immunoglobulin isotype composition of poliovirus antibodies was studied by isotype-specific solid-phase radio-immunoassay (RIA) in four patients with paralytic poliomyelitis, five adults receiving live poliovirus vaccine as a booster immunization, and seven children receiving first doses of inactivated poliovirus vaccine. In paralytic poliomyelitis serum and cerebrospinal fluid (CSF) poliovirus antibodies were mainly of IgG1, IgG3, and IgA isotypes. IgM antibodies were found in sera but not in CSF. Either IgG2 and IgG4 antibodies were undetectable or the titers were low. In adults who had received live trivalent poliovirus vaccine, antibodies against poliovirus type 3 were detected in IgG1 (53% of total antibodies), IgG3 (25%), IgM (9%), IgA (8%), IgG2 (3%), and IgG4 (2%) isotypes. In prevaccination and late postvaccination sera the share of IgG3 antibodies was exceptionally high (35%). In children who received inactivated poliovirus vaccine, antibodies developed in IgG1 (53-61% of total antibodies for poliovirus types 1, 2, and 3), IgG3 (12-21%), and IgM (23-33%) isotypes. Antibody levels in IgG2, IgG4, and IgA isotypes were low and observed only in a few cases. Like other viral antibodies IgG1 and IgG3 isotypes were the major IgG subclasses in poliovirus antibodies.

Influence of several bacterial and viral vaccines on hepatic drug metabolism in mice

Pentobarbital-induced sleeping time was found to be significantly prolonged in mice within at least 4 days following either whooping cough, tetanus, rubella or poliomyelitis vaccination. By contrast, barbital-induced sleeping time remained unaffected, These findings provide further evidence of a correlation between inhibition of liver drug metabolizing enzymes and stimulation of the immune response.

Whooping cough vaccination: the case presented by the British national press

The coverage of whooping cough and its vaccine by the British press was content-analysed and compared with that of four other diseases for which articles were relatively common over the same time period. The results indicated that the topics were dealt with differently by the press, with whooping cough vaccination being seen as more risky than the others, requiring both medical advice and a decision before being accepted. The rather negative attitude to this vaccine emphasizes the problems associated with it rather than its preventive qualities. There was little evidence of a balanced discussion of the issues found in the medical literature, although accusations against the lay-press for providing largely inaccurate and sensationalized articles were found to be unsupported. The press were found, however, to publish many event-orientated articles, particularly those about specific individuals.

[Induction of mutations in mammalian cells by the action of live vaccinal strains of poliomyelitis virus]

The attenuated strains' poliomyelitis virus induces mutagenesis in human and Chinese hamster cultured cells. The mutagenic action of the poliovirus is detected at chromosome and gene levels and directly depends on the multiplicity of cell infection. Possibilities for developing nonmutagenic antivirus vaccines are discussed.

The evaluation of a physical method for the quantification of inactivated poliovirus particles and its relationship to D-antigenicity and potency testing in rats

The use of a density gradient procedure for the quantification of intact, inactivated poliovirus particles in vaccine preparations is described. The procedure is both sensitive and highly reproducible and the results correlate with those of potency tests in rats and with D-antigen content as measured by ELISA. Because of the occasional ambiguity observed with D-antigen assays, it is suggested that the density gradient procedure will provide valuable additional information for the in vitro assessment of inactivated poliovirus preparations.

The immunological response of Nigerian infants to attenuated and inactivated poliovaccines

A comparison was made of the immunity conferred by injected formalin-killed poliomyelitis vaccine and orally administered attenuated poliomyelitis vaccine in Nigerian infants under tropical conditions where interfering enteroviruses have caused poor conversion rates with attenuated poliomyelitis vaccine. Two hundred and thirty infants completed the immunization schedules. The levels of antibodies to polioviruses were assessed before immunization and at periodic intervals during the trial. Seventy-four per cent, 72% and 85% of the children lacked antibodies to poliovirus types 1, 2 and 3 respectively at 6 months if they received no vaccine, the comparative proportions respectively were 52%, 8% and 48% if they had oral attenuated poliovaccine and 2%, 4% and 0% if they had three doses of inactivated poliovaccine. It is suggested that killed poliovaccine incorporated in a quadruple vaccine may have a place in developing countries like Nigeria in the control of diphtheria, tetanus, whooping cough and poliomyelitis.

[Effect of viral vaccines on animal bone marrow cell chromosomes]

A comparative study on the effect of a number of viral vaccines (live and inactivated vaccinia, poliovirus type II, measles, rabies vaccines) on chromosomes of mouse bone marrow cells was carried out. Most vaccines were found to impair the process of first divisions of these cells after vaccination. Live vaccinia vaccine and live fixed rabies virus cause an increase in the rate of structural chromosome aberrations at later intervals, 30-90 days after immunization. The main type of chromosome disorders is chromatid break. Some of the live vaccines studied (poliovaccine type II, measles vaccine) and inactivated vaccines caused no increase in the rate of cromosome structure disorders as compared to the control. Live fixed rabies virus exerts a stronger impairing effect on division of mouse bone marrow cells than a rabies vaccine with residual virulence. A rabies vaccine completely inactivated by UV-irradiation had no impairing effect on chromosomes of immunized animals. Thus, some live vaccines, unlike inactivated ones, cause chromosome disorders in bone marrow cells of mice late after immunization and, apparently, subsequent death of some cells with the most important distrubances.

[Study of the chromosomes in the bone marrow cells of mice inoculated subsequently with various vaccines]

Studies in the effect of a complex of inoculating preparations (poliovaccine, APDD-vaccine, smallpox vaccine, measles vaccine) on dividing cells of bone marrow in mice in line CC57Br showed that a reduction of the interval between introduction of vaccines different in the antigenic respect from 14 days to 4 days results in an increase in frequency of structural chromosomal aberrations 1-2 months after the whole course of inoculations.

Acquired dysgammaglobulinaemia in a young man

A 26-year-old man had been subject to repeated infections since the age of 15. He was found to have complete absence of isohaemagglutinins, even though he was blood group O, and absence of antibodies to any of the common bacterial and viral infections. A full course of typhoid–paratyphoid A and B vaccine produced no antibody response and a large dose of inactivated poliomyelitis vaccine produced only a minimal response. Estimation of the immunoglobulin levels in the serum revealed a normal amount of IgG globulin, increased amounts of IgM globulin and diminished amounts of IgA globulin.