Article

Consistency of Bordetella pertussis vaccine seed strains and potency of whole-cell pertussis vaccine still in use in Poland

Biologicals (Impact Factor: 1.41). 01/2014; 42(2). DOI: 10.1016/j.biologicals.2013.11.006
Source: PubMed

ABSTRACT In Poland, where the wP vaccine has been used since 1960, pertussis rates increased in the mid-1990s. In 2012, the rate of pertussis recognised by surveillance was unexpectedly found to be two-fold higher than in the previous decade. Quality measures on potency and vaccine working seeds were introduced, to confirm the possible impact of manufacturing inconsistency or potency lowering on the observed increase in pertussis. Shewhart charts on potency values for lots released between 2001 and 2013 did not reveal any significant fluctuations. Working seeds of three vaccine strains used within last decade for wP manufacturing belong to the PFGE group III and were highly related. According to PFGE and SDS-PAGE data, all vaccine strains were found consistent according profiling on the genomic and protein levels. According to the sequencing data, they harboured ptxA2, ptxC1, prn1, fim2-1, fim3-1, tcfA2, ptxP1 and were assigned as MLST-2 type. Other factors apart from vaccine manufacturing inconsistency might be responsible for the increase in pertussis noted in 2012 in Poland.

Download full-text

Full-text

Available from: Anna Lutyńska, Jan 30, 2014
2 Followers
 · 
124 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: A mouse intracerebral challenge model is used for potency testing of whole-cell pertussis (wP) vaccines. We investigated the use of a mouse nasopharyngeal challenge model, which better reflects the clinical features of pertussis disease, to differentiate between efficacy of wP vaccines. Methods: Efficacy of three wP vaccines (Quinvaxem(®), Easyfive(®) and Pentavac(®)) was tested in the nasopharyngeal challenge model. Mice were vaccinated at 4 and 7 weeks and challenged with Bordetella pertussis at 9 weeks. Vaccine efficacy was determined based on CFU in the lungs 5 days after challenge. Results: The mouse nasopharyngeal challenge model has the capacity to differentiate between the efficacy of whole cell pertussis vaccines. Conclusion: The mouse nasopharyngeal challenge model could be considered as a potency and release assay for wP vaccines. Whether this model directly correlates with clinical vaccine efficacy requires further investigations. Whether this model directly correlates with clinical vaccine efficacy requires further investigations. The mouse nasopharyngeal challenge model could be considered as a potency and release assay for wP vaccines.
    Expert Review of Vaccines 07/2014; 13(10):1-6. DOI:10.1586/14760584.2014.938642 · 4.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to characterise Bordetella pertussis isolates circulating in Poland since 1959. Sequence analysis of ptxA, ptxC, prn, tcfA, fim2, fim3 and ptxP for 175 clinical isolates and currently and previously used vaccine strains was performed. Clinical isolates from the period 1995-2013 were found to be different to three currently used vaccine strains harbouring the allelic combination ptxA2-ptxC1-ptxP1-prn1-tcfA2-fim2-1-fim3-1, seen frequently in Poland in the early pertussis vaccination period but not found after 1995. Generally, among B. pertussis isolates from the period 2000-2013, two genotypes predominated, ptxA1-ptxC1-ptxP1-prn1-tcfA2-fim2-2-fim3-1 and ptxA1-ptxC1-ptxP1-prn2-tcfA2-fim2-1-fim3-1, with frequencies of 45 % and 32.5 %, respectively. The isolates harbouring ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-2 and ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-1 profiles, currently highly prevalent within other European Union (EU) countries, were rarely found in Poland, as they circulated in the period 2000-2013 with frequencies of 10 % and 5 %, respectively. We hypothesise that several previous changes of strain composition in whole-cell pertussis vaccine produced locally and used since 1960 in Poland resulted in a more diverse immune pressure in the population, resulting in different prevalence of alleles compared to elsewhere.
    European Journal of Clinical Microbiology 08/2014; 34(1). DOI:10.1007/s10096-014-2216-6 · 2.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite more than 50 years of vaccination, pertussis is still an endemic disease, with regular epidemic outbreaks. With the exception of Poland, European countries have replaced whole-cell vaccines (WCVs) by acellular vaccines (ACVs) in the 1990s. Worldwide, antigenic divergence in vaccine antigens has been found between vaccine strains and circulating strains. In this work, 466 Bordetella pertussis isolates collected in the period 1998-2012 from 13 European countries were characterised by multi-locus antigen sequence typing (MAST) of the pertussis toxin promoter (ptxP) and of the genes coding for proteins used in the ACVs: pertussis toxin (Ptx), pertactin (Prn), type 2 fimbriae (Fim2) and type 3 fimbriae (Fim3). Isolates were further characterised by fimbrial serotyping, multi-locus variable-number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE). The results showed a very similar B. pertussis population for 12 countries using ACVs, while Poland, which uses a WCV, was quite distinct, suggesting that ACVs and WCVs select for different B. pertussis populations. This study forms a baseline for future studies on the effect of vaccination programmes on B. pertussis populations.
    European Journal of Clinical Microbiology 12/2014; 34(4). DOI:10.1007/s10096-014-2297-2 · 2.54 Impact Factor