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BACKGROUND: Pneumococcal conjugate vaccines (PCVs) induce serotype-specific IgG antibodies, effectively reducing vaccine-serotype carriage and invasive pneumococcal disease (IPD). IgG production wanes approximately 1 month after vaccination in absence of serotype-specific exposure. With uncertainty surrrounding correlate of protection (CoP) estimates and with persistent vaccine-serotype carriage and vaccine-serotype IPD after PCV13 introduction, we aimed to profile population-level immunogenicity among children younger than 5 years in Blantyre, Malawi. METHODS: For this serosurveillance study, we used a random subset of samples from a prospective population-based serosurvey in Blantyre, Malawi, done between Dec 16, 2016, and June 27, 2018. Sample selection was based on age category optimisation among children younger than 5 years, adequate sample volume, and available budget. We measured serotype-specific IgGs against the 13 vaccine serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) and two non-vaccine serotypes (12F and 33F), as well as IgGs against three pneumococcal proteins (PsaA, NanA, and Ply), using ELISA and a direct-binding electrochemiluminescence-based multiplex assay. We estimated population-level, serotype-specific immunogenicity profiles using a linear spline regression model. Analyses included samples stratified to 20 3-month age strata (eg, age

BackgroundPneumococcal conjugate vaccines (PCVs) induce serotype-specific IgG antibody, effectively reducing vaccine-serotype (VT) carriage and invasive pneumococcal disease (IPD). IgG production wanes approximately 1 month after vaccination in absence of serotype-specific exposure. With uncertainty around correlate of protection (CoP) estimates and with persistent VT carriage and VT-IPD following PCV13 introduction, we undertook population-level immunogenicity profiling among children MethodsFor 638 children, capsule-specific IgG to PCV13 VTs, two non-VTs, and IgG to three pneumococcal proteins were measured using an enzyme-linked immunosorbent assay and a direct-binding electrochemiluminescence-based multiplex assay. A linear spline regression model estimated population-level, serotype-specific immunogenicity profiles. A linear regression model was used to validate putative CoPs.FindingsImmunogenicity profiles revealed a consistent pattern among VTs except serotype 3: a vaccine-induced IgG peak followed by waning to a nadir and subsequent increase in titre. For serotype 3 there was no apparent vaccine-induced increase. Heterogeneity in parameters included age range at post-vaccination-nadir (11·2 [19F, 23F] to 27·3 [7F] months). Titres dropped below IPD CoPs among 9 VTs and below carriage CoPs for 10 VTs. Study data estimated a range of carriage CoPs (0·50μg/mL to 2·5μg/mL). Increasing antibody among older children and seroincident events were consistent with ongoing VT exposure.InterpretationA 3+0 PCV13 schedule with high uptake has not led to sustained population-level antibody immunity beyond the first year of life. Indeed, post-vaccine antibody concentrations dropped below putative CoPs for several VTs, potentially contributing to persistent VT carriage and residual VT-IPD in Malawi and other similar settings.FundingBill & Melinda Gates Foundation, Wellcome UK, and National Institute for Health & Care Research.

There are concerns that pneumococcal conjugate vaccines (PCVs) in sub-Saharan Africa sub-optimally interrupt Streptococcus pneumoniae vaccine-serotype (VT) carriage and transmission. Here we assess PCV carriage using rolling, prospective nasopharyngeal carriage surveys between 2015 and 2018, 3.6–7.1 years after Malawi’s 2011 PCV13 introduction. Carriage decay rate is analysed using non-linear regression. Despite evidence of reduction in VT carriage over the study period, there is high persistent residual carriage. This includes among PCV-vaccinated children 3–5-year-old (16.1% relative reduction from 19.9% to 16.7%); PCV-unvaccinated children 6–8-year-old (40.5% reduction from 26.4% to 15.7%); HIV-infected adults 18-40-years-old on antiretroviral therapy (41.4% reduction from 15.2% to 8.9%). VT carriage prevalence half-life is similar among PCV-vaccinated and PCV-unvaccinated children (3.26 and 3.34 years, respectively). Compared with high-income settings, there is high residual VT carriage 3.6–7.1 years after PCV introduction. Rigorous evaluation of strategies to augment vaccine-induced control of carriage, including alternative schedules and catch-up campaigns, is required., Impact of pneumococcal conjugate vaccines (PCV) in controlling carriage needs to be evaluated to inform vaccine policy. Here, Swarthout et al. show in a prospective rolling cross-sectional study in Malawi a high residual prevalence of vaccine-serotype S. pneumoniae 7 years after PCV introduction.

Background In November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to 7 years after introduction (2015–2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in high-income countries, and impact was asymmetric across age groups. Methods A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage. Results Accumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49–82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0–9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02–81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection. Conclusions There are both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by an age-specific, local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact on carriage (and therefore herd protection) has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.

BackgroundIn November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to seven years after introduction (2015-2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in developed countries, and VT impact was surprisingly asymmetric across age-groups. A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage.ResultsAccumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age-groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49-82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0-9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02-81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection.ConclusionsWe have identified both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by age-related characteristics of the local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.

BackgroundThere are concerns that pneumococcal conjugate vaccines (PCV) in sub-Saharan Africa sub-optimally interrupt vaccine-serotype (VT) carriage and transmission, thus limiting vaccine-induced direct and indirect protection. We assessed carriage in vaccinated children and unvaccinated populations targeted for indirect protection, between 4 and 7 years after Malawi’s November 2011 introduction of PCV13 using a 3+0 schedule.MethodsWe conducted sequential prospective nasopharyngeal carriage surveys between 2015 and 2018 among healthy PCV-vaccinated and PCV-unvaccinated children, and HIV-infected adults. VT and NVT carriage risk by age was analysed by non-linear regression.ResultsAmong PCV-vaccinated children, there was a 24% relative reduction in carriage, from a mean 21.1% to 16.1%; 45% reduction among older PCV-unvaccinated children, from 27.5% to 15.2%; 41.4% reduction among adults, from 15.2% to 8.9%. Using carriage data from children 3.6 to 10 years of age, VT carriage probability declined with age, with a similar prevalence half-life among PCV-vaccinated (3.34 years) and PCV-unvaccinated (3.26 years) children.ConclusionCompared to high-income settings, the 3+0 schedule in Malawi has led to a sub-optimal reduction in pneumococcal carriage prevalence. This is likely due to recolonisation of vaccinated children with waning vaccine-induced immunity, resulting in insufficient indirect protection of unvaccinated populations. Rigorous evaluation of strategies to augment vaccine-induced control of carriage, including alternative schedules and catch-up campaigns is required.

This June 2015 issue of the Malawi Medical Journal is published on the back of Malawi's hosting of the 11th annual African Journal Partnership Project (AJPP) Meeting, held on 11 and 12 June at Game Haven Lodge, Chimwenya Game Park in Bvumbwe. And what a captivating, inspiring meeting it was. Indeed, it was captivating enough to inspire me to write my first editorial as MMJ intern—to express, to the MMJ audience, just how lively and infectious the enthusiasm was in that boardroom over those two enlightening days. This year's theme was “Promoting Scientific Integrity for African Medical Science and Journals”. We welcomed AJPP co-directors Annette Flanagin (of the Journal of the American Medical Association, JAMA), David Ofori-Adjei (of the Ghana Medical Journal), and Steve Morrissey (of the New England Journal of Medicine). Editors and representatives of the thirteen journals that make up the AJPP and representatives of the programme's various sponsoring and supporting organizations were also in attendance. For those of you who are unfamiliar with the AJPP, let me start with a bit of background.1,2 The AJPP was born out of an idea conceived, in 2003, by the Fogarty International Center (FIC) and the National Library of Medicine (NLM), both of which are entities operated by the United States federal government under the National Institutes of Health (NIH) umbrella. The idea was to address the need for capacity building among Africa's biomedical and health journals by partnering a select few of them with leading biomedical journals in the United States and the United Kingdom. In September 2003, what would later become the AJPP was initiated at a meeting in London hosted by The BMJ (British Medical Journal). MMJ was partnered with JAMA as one of the founding partnerships. The other founding partnerships were African Health Sciences (based in Uganda) with The BMJ, the Ghana Medical Journal with The Lancet, and Mali Medical with Environmental Health Perspectives and the American Journal of Public Health. With the United States-based Council of Science Editors (CSE) serving as its administrative body, the AJPP was officially up and running by May 2004, and eleven years, two new partnerships (and two additional African journals joining existing partnerships) later, the programme is flourishing. The two newer partnerships, added in in 2008, have the Ethiopian Journal of Health Sciences paired with Annals of Internal Medicine, and the Medical Journal of Zambia with the New England Journal of Medicine. In 2013, the Sierra Leone Journal of Biomedical Research joined the Ghana Medical Journal-Lancet pairing and Annales Africaines de Medicine, which is published in the Democratic Republic of Congo, joined the Mali Medical-Environmental Health Perspectives partnership. During my time as MMJ intern prior to this month's meeting, I had only vaguely felt the AJPP's presence. The article detailing the MMJ editor and desk editor's 2011 trip to the JAMA offices in Chicago3 was one of the first MMJ articles I read when I started the job, and my curiosity has occasionally led me to AJPP-related news articles online, the websites of AJPP partner journals, and the AJPP site1 and Twitter page (@AJPPEditors). Indeed, my position at MMJ was only made possible by the AJPP's existence, and obviously the hardware and software in our office did not just magically appear here, but this meeting was the first time I had the opportunity to experience belonging to the AJPP family. It did not disappoint. I went into the venue with an open mind, expecting only that the conference would be educational, that I would be surrounded by wise and experienced professionals, and that if I endured the jam-packed schedule without succumbing to the sleep deprivation accrued from having been on call three times in the preceding ten days, I could possibly absorb some of that wisdom and experience. But thanks to the tangible buzz that could be felt from the very first interactions at breakfast on day one, this conference was not endured; it was savoured. The participants were at once approachable, humble, passionate, and engaging. As the actual proceedings of the meeting flew by, I found myself captivated throughout: from bioethics specialist Prof. Mfutso-Bengo's keynote address, in which he helped define what scientific integrity and ethical research reporting means by citing the Chichewa word choonadi, meaning “that which you can see,” and therefore “truth” (Chichewa can be so delightful sometimes); to hearing, from each editor, about all of the successes, challenges, and progress of the African partner journals; to meeting with the editors and participants at tea breaks and meals; to participating in interactive discussions about the ethical implications of hypothetical publicationrelated scenarios; to learning details about what acronyms and organizational names like DOI, CrossRef, EQUATOR, and INASP actually mean—I easily forgot about my sleep deprivation. If some of that does not sound so exciting, I cannot emphasize enough that it was the passion and enthusiasm of the conference participants that made it exciting. As one representative put it when the meeting was wrapping up: “It wasn't even boring!” (as such meetings are supposed to be, right?). It was far from boring. And judging from the group that was present in Bvumbwe, it is easy to see how the AJPP journals on this continent continue to thrive and grow. Hopefully, this is just the beginning of my contribution to that growth. Andrew Mataya is the Malawi Medical Journal intern and an intern medical doctor at Queen Elizabeth Central Hospital in Blantyre.

Introduction : The University of Malawi's College of Medicine produces almost all of the medical interns working at Malawi's two largest public hospitals: Queen Elizabeth Central Hospital in Blantyre, and Kamuzu Central Hospital in Lilongwe. To earn full medical council registration, new graduates must complete an 18-month internship at either site. This study attempted to determine general levels of job satisfaction and commitment among Malawian medical interns, and to rank categorical factors according to impact on intern job satisfaction and commitment. These factors were also examined in terms of influence on bringing about an intern strike in late 2010, early 2011. Methods : Sixty-one of 70 interns working during the study period completed a job satisfaction survey. Questionnaire items addressed ten "factors": (1) hours and pay, (2) work content, (3) working conditions, (4) relationships with senior staff, (5) workplace relationships with peers, (6) educational environment, (7) internal factors, (8) quality of life, (9) autonomy and self-worth, and (10) future career prospects . Analysis for this cross-sectional study included quantification and comparisons of overall and category-specific satisfaction levels, using ANOVA and Student's t-test. Results : Sixty-nine percent then 57% of interns identified themselves as satisfied at the beginning and end of the questionnaire, respectively; 97% of the interns indicated job commitment at both instances of asking. Factors influencing job satisfaction most strongly were those that participants were least satisfied with. Conclusion : Future research and interventions aimed at improving intern job satisfaction in Malawi should focus on assessing and improving remuneration, working hours, and physical working conditions.