Lack of effectiveness of 13-valent pneumococcal conjugate vaccination against pneumococcal carriage density in Papua New Guinean infants
- Authors: Britton, Kathryn , Pickering, Janessa , Pomat, William , de Gier, Camilla , Greenhill, Andrew
- Date: 2021
- Type: Text , Journal article
- Relation: Vaccine Vol. 39, no. 38 (2021), p. 5401-5409
- Full Text:
- Reviewed:
- Description: Background: Papua New Guinea (PNG) introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in 2014, with administration at 1, 2, and 3 months of age. PCV13 has reduced or eliminated carriage of vaccine types in populations with low pneumococcal carriage prevalence, carriage density and serotype diversity. This study investigated PCV13 impact on serotype-specific pneumococcal carriage prevalence, density, and serotype diversity in PNG infants, who have some of the highest reported rates of pneumococcal carriage and disease in the world. Methods: Nasopharyngeal swabs were collected at 1, 4 and 9 months of age from PCV13-vaccinated infants (n = 57) and age-/season-matched, unvaccinated infants (at approximately 1 month, n = 53; 4 months, n = 57; 9 months, n = 52). Serotype-specific pneumococcal carriage density and antimicrobial resistance genes were identified by qPCR and microarray. Results: Pneumococci were present in 89% of swabs, with 60 different serotypes and four non-encapsulated variants detected. Multiple serotype carriage was common (47% of swabs). Vaccine type carriage prevalence was similar between PCV13-vaccinated and unvaccinated infants at 4 and 9 months of age. The prevalence of non-vaccine type carriage was also similar between cohorts, with non-vaccine types present in three-quarters of samples (from both vaccinated and unvaccinated infants) by 4 months of age. The median pneumococcal carriage density was high and similar at each age group (~7.0 log10 genome equivalents/mL). PCV13 had no effect on overall pneumococcal carriage density, vaccine type density, non-vaccine type density, or the prevalence of antimicrobial resistance genes. Conclusion: PNG infants experience dense and diverse pneumococcal colonisation with concurrent serotypes from 1 month of age. PCV13 had no impact on pneumococcal carriage density, even for vaccine serotypes. The low prevalence of vaccine serotypes, high pneumococcal carriage density and abundance of non-vaccine serotypes likely contribute to the lack of PCV13 impact on carriage in PNG infants. Indirect effects of the infant PCV programs are likely to be limited in PNG. Alternative vaccines with broader coverage should be considered. © 2021 The Authors. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Andrew Greenhill" is provided in this record**
A high burden of asymptomatic gastrointestinal infections in traditional communities in Papua New Guinea
- Authors: Horwood, Paul , Soli, Kevin , Maure, Tobias , Naito, Yuichi , Morita, Ayako , Natsuhara, Kazumi , Tadokoro, Kiyoshi , Baba, Jun , Odani, Shingo , Tomitsuka, Eriko , Igai, Katsura , Larkins, Jo-Ann , Siba, Peter , Pomat, William , McBryde, Emma , Umezaki, Masahiro , Greenhill, Andrew
- Date: 2017
- Type: Text , Journal article
- Relation: American Journal of Tropical Medicine and Hygiene Vol. 97, no. 6 (2017), p. 1872-1875
- Full Text:
- Reviewed:
- Description: Stool samples were collected from 148 healthy adults living a traditional subsistence lifestyle in Papua New Guinea and screened for enteric pathogens using real-time RT-PCR/PCR assays. Enteric pathogens were detected in a high proportion (41%) of individuals. Clear differences were observed in the detection of pathogens between highland and lowland communities. In particular, there was a marked difference in detection rates of norovirus GII (20% and 0%, respectively) and Shigella sp. (15% and 0%, respectively). Analysis of the relationship between enteric pathogen carriage and microbial community composition of participants, using box plots to compare specific normal flora population numbers, did not suggest that gut microbial composition was directly associated with pathogen carriage. This study suggests that enteric pathogens are common in healthy individuals in Papua New Guinean highland communities, presumably acting as a reservoir of infection and thus contributing to a high burden of gastrointestinal illnesses.
Gut microbiota composition in obese and non-obese adult relatives from the highlands of Papua New Guinea
- Authors: Jonduo, Marinjho , Wawae, Lorry , Masiria, Geraldine , Suda, Wataru , Hattori, Masahira , Takayasu, Lena , Abdad, Mohammad , Greenhill, Andrew , Horwood, Paul , Pomat, William , Umezaki, Masahiro
- Date: 2020
- Type: Text , Journal article
- Relation: FEMS microbiology letters Vol. 367, no. 19 (2020), p.
- Full Text:
- Reviewed:
- Description: Obesity is a condition that results from an imbalance between energy intake and expenditure. Recently, obesity has been linked to differences in the composition of gut microbiota. To examine this association in Papua New Guinea (PNG) highlanders, fecal samples were collected from 18 adults; nine obese participants were paired with their non-obese relative. Amplification of the 16S rRNA gene targeting the V1-V2 region was performed on DNA extracts for each participant, with high-quality sequences selected and used for operational taxonomic unit clustering. The data showed Firmicutes and Bacteroidetes were the two dominant phyla, while at genus level Prevotella was the most dominant genus in all of the samples. Nonetheless, statistical evaluation of potential association between nutritional status and bacterial abundance at both phyla and genus levels showed no significant difference. Further studies, ideally in both rural and urban areas, are needed to evaluate the role of the gut microbiome in the occurrence of obesity in PNG and other resource-limited settings. © The Author(s) 2020. Published by Oxford University Press on behalf of FEMS.
Safety and immunogenicity of pneumococcal conjugate vaccines in a high-risk population : A randomized controlled trial of 10-valent and 13-valent pneumococcal conjugate vaccine in Papua New Guinean infants
- Authors: Pomat, William , Van Den Biggelaar, Anita , Wana, Sandra , Francis, Jacinta , Solomon, Vela , Greenhill, Andrew , Ford, Rebecca , Orami, Tilda , Passey, Megan , Jacoby, Peter , Kirkham, Lea-Ann , Lehmann, Deborah , Richmond, Peter
- Date: 2019
- Type: Text , Journal article
- Relation: Clinical Infectious Diseases Vol. 68, no. 9 (2019), p. 1472-1481
- Full Text:
- Reviewed:
- Description: Background. There are little data on the immunogenicity of PCV10 and PCV13 in the same high-risk population. Methods. PCV10 and PCV13 were studied head-to-head in a randomized controlled trial in Papua New Guinea in which 262 infants received 3 doses of PCV10 or PCV13 at 1, 2, and 3 months of age. Serotype-specific immunoglobulin G (IgG) concentrations, and pneumococcal and nontypeable Haemophilus influenzae (NTHi) carriage were assessed prevaccination and at 4 and 9 months of age. Infants were followed up for safety until 9 months of age. Results. One month after the third dose of PCV10 or PCV13, 80% of infants had IgG concentrations ≥0.35µg/mL for vaccine serotypes, and 6 months postvaccination IgG concentrations ≥0.35 µg/mL were maintained for 8/10 shared PCV serotypes in > 75% of children vaccinated with either PCV10 or PCV13. Children carried a total of 65 different pneumococcal serotypes (plus nonserotypeable). At 4 months of age, 92% (95% confidence interval [CI] 85–96) of children vaccinated with PCV10 and 81% (95% CI 72–88) vaccinated with PCV13 were pneumococcal carriers (P = .023), whereas no differences were seen at 9 months of age, or for NTHi carriage. Both vaccines were well tolerated and not associated with serious adverse events. Conclusions. Infant vaccination with 3 doses of PCV10 or PCV13 is safe and immunogenic in a highly endemic setting; however, to significantly reduce pneumococcal disease in these settings, PCVs with broader serotype coverage and potency to reduce pneumococcal carriage are needed. Clinical Trials Registration. NCT01619462.
The PneuCarriage Project : A multi-centre comparative study to identify the best serotyping methods for examining pneumococcal carriage in vaccine evaluation studies
- Authors: Satzke, Catherine , Dunne, Eileen , Porter, Barbara , Klugman, Keith , Mulholland, Kim , PneuCarriage project group , Greenhill, Andrew
- Date: 2015
- Type: Text , Journal article
- Relation: PLoS Medicine Vol. 12, no. 11 (2015), p. 1-30
- Full Text:
- Reviewed:
- Description: Background: The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Methods and Findings: Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Conclusions: Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor serotype populations. Microarray with a culture amplification step was the top-performing method. Results from this comprehensive evaluation will inform future vaccine evaluation and impact studies, particularly in low-income settings, where pneumococcal disease burden remains high. © 2015 Satzke et al. *For a complete list of authors, please see acknowledgments in the published article.
Influenza A(H5N1) viruses with A(H9N2) single gene (matrix or PB1) reassortment isolated from Cambodian live bird markets
- Authors: Suttie, Annika , Karlsson, Erik , Deng, Yi-Mo , Horm, Srey , Yann, Sokhoun , Tok, Songha , Sorn, San , Holl, Davun , Tum, Sothyra , Hurt, Aeron , Greenhill, Andrew , Barr, Ian , Horwood, Paul , Dussart, Philippe
- Date: 2018
- Type: Text , Journal article
- Relation: Virology Vol. 523, no. (2018), p. 22-26
- Full Text:
- Reviewed:
- Description: Live bird market surveillance for avian influenza viruses in Cambodia in 2015 has led to the detection of two 7:1 reassortant influenza A(H5N1) clade 2.3.2.1c viruses. These reassortant strains, designated A/duck/Cambodia/Z564W35M1/2015 and A/chicken/Cambodia/Z850W49M1/2015, both contained a single gene (PB1 and matrix gene, respectively) from concurrently circulating A(H9N2) influenza viruses. All other viral genes from both isolates clustered with A(H5N1) clade 2.3.2.1 viruses. Continued and prolonged co-circulation of influenza A(H5N1) and A(H9N2) viruses in Cambodian live bird markets may present a risk for the emergence of novel influenza reassortant viruses with negative agricultural and/or public health implications. © 2018