Effect of a Reduced PCV10 Dose Schedule on Pneumococcal Carriage in Vietnam.

Background: After pneumococcal disease and colonization have been controlled through vaccination campaigns, a reduced pneumococcal conjugate vaccine (PCV) schedule may be sufficient to sustain that control at reduced costs.

Methods: We investigated whether a single primary dose and booster dose (1p+1) of the 10-valent PCV (PCV10) would be noninferior to alternative dose schedules in sustaining control of carriage of pneumococcal serotypes included in the vaccine. In Nha Trang, Vietnam, an area in which PCV had not been used previously, a PCV10 catch-up campaign was conducted in which the vaccine was offered to children younger than 3 years of age, after which a cluster-randomized trial was conducted in which children received PCV10 at 2, 3, and 4 months of age (3p+0 group); at 2, 4, and 12 months of age (2p+1 group); at 2 and 12 months of age (1p+1 group); or at 12 months of age (0p+1 group).

Effect of pneumococcal conjugate vaccination on pneumococcal carriage in hospitalised children aged 2-59 months in Mongolia: an active pneumonia surveillance programme.

Background: Data on changes in pneumococcal serotypes in hospitalised children following the introduction of the pneumococcal conjugate vaccine (PCV) in low-income and middle-income countries are scarce. In 2016, Mongolia introduced the 13-valent PCV (PCV13) into the national immunisation programme. We aimed to describe the trend and impact of PCV13 introduction on pneumococcal carriage in hospitalised children aged 2-59 months with pneumonia in Mongolia over a 6-year period.

The potential of residual clinical Group B Streptococcus swabs for assessing the vaginorectal microbiome in late pregnancy.

The maternal pregnancy microbiome (including genitourinary and gut) has been linked to important pregnancy/birth and later childhood health outcomes. However, such sampling as part of large population cohort studies is logistically and financially challenging. Many countries routinely collect vaginal or vaginal-rectal swabs in late pregnancy for Group B Streptococcus (GBS) screening, but their utility for population-based research is still unclear.

Respiratory Syncytial Virus and Influenza Infections in Children in Ulaanbaatar, Mongolia, 2015-2021.

Background: Data available for RSV and influenza infections among children < 2 years in Mongolia are limited. We present data from four districts of Ulaanbaatar from April 2015 to June 2021.

Methods: This study was nested in an enhanced surveillance project evaluating pneumococcal conjugate vaccine (PCV13) impact on the incidence of hospitalized lower respiratory tract infections (LRTIs).

Effect of Pneumococcal Conjugate Vaccine on Pneumonia Incidence Rates among Children 2-59 Months of Age, Mongolia, 2015-2021.

Starting in June 2016, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced into the routine immunization program of Mongolia by using a 2+1 dosing schedule, phased by district. We used prospective hospital surveillance to evaluate the vaccine's effect on pneumonia incidence rates among children 2-59 months of age over a 6-year period. Of 17,607 children with pneumonia, overall adjusted incidence rate ratios showed decreased primary endpoint pneumonia, very severe pneumonia, and probable pneumococcal pneumonia until June 2021.

Immunization with a whole cell vaccine reduces pneumococcal nasopharyngeal density and shedding, and middle ear infection in mice.

Pneumococcal Conjugate Vaccines (PCVs) have substantially reduced the burden of disease caused by Streptococcus pneumoniae (the pneumococcus). However, protection is limited to vaccine serotypes, and when administered to children who are colonized with pneumococci at the time of vaccination, immune responses to the vaccine are blunted. Here, we investigate the potential of a killed whole cell pneumococcal vaccine (WCV) to reduce existing pneumococcal carriage and mucosal disease when given therapeutically to infant mice colonized with pneumococci.

serotype 33G: genetic, serological, and structural analysis of a new capsule type.

(the pneumococcus) is a bacterial pathogen with the greatest burden of disease in Asia and Africa. The pneumococcal capsular polysaccharide has biological relevance as a major virulence factor as well as public health importance as it is the target for currently licensed vaccines. These vaccines have limited valency, covering up to 23 of the >100 known capsular types (serotypes) with higher valency vaccines in development.

Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial.

Background: Interest in reduced-dose pneumococcal conjugate vaccine (PCV) schedules is growing, but data on their ability to provide direct and indirect protection are scarce. We evaluated 1 + 1 (at 2 months and 12 months) and 0 + 1 (at 12 months) schedules of PCV10 or PCV13 in a predominately unvaccinated population.

Methods: In this parallel, single-blind, randomised controlled trial, healthy infants aged 2 months were recruited from birth records in three districts in Ho Chi Minh City, Vietnam, and assigned (4:4:4:4:9) to one of five groups: PCV10 at 12 months of age (0 + 1 PCV10), PCV13 at 12 months of age (0 + 1 PCV13), PCV10 at 2 months and 12 months of age (1 + 1 PCV10), PCV13 at 2 months and 12 months of age (1 + 1 PCV13), and unvaccinated control.

A systematic review of pneumococcal conjugate vaccine impact on pneumococcal nasopharyngeal colonisation density in children under 5 years of age.

Background: High pneumococcal carriage density has been associated with severe pneumonia in some settings. The impact of pneumococcal conjugate vaccines (PCVs) on pneumococcal carriage density has been variable. The aim of this systematic literature review is to describe the effect of PCV7, PCV10 and PCV13 on pneumococcal colonisation density in children under five years old.

Effect of different schedules of ten-valent pneumococcal conjugate vaccine on pneumococcal carriage in Vietnamese infants: results from a randomised controlled trial.

Background: WHO recommends a three-dose infant pneumococcal conjugate vaccine (PCV) schedule administered as a two-dose primary series with booster (2 + 1) or a three-dose primary series (3 + 0). Data on carriage impacts of these and further reduced PCV schedules are needed to inform PCV strategies. Here we evaluate the efficacy against carriage of four different PCV10 schedules.

PneumoKITy: A fast, flexible, specific, and sensitive tool for serotype screening and mixed serotype detection from genome sequence data.

Determination of serotypes of is essential for monitoring current vaccine programmes. Since October 2017, pneumococcal serotypes in England have been derived from whole genome sequencing (WGS) data using our bioinformatic tool PneumoCaT. That tool was designed for serotype determination from pure cultures in a reference laboratory.

Impact of COVID-19 Nonpharmaceutical Interventions on Pneumococcal Carriage Prevalence and Density in Vietnam.

Nonpharmaceutical interventions (NPIs) implemented to contain SARS-CoV-2 have decreased invasive pneumococcal disease. Previous studies have proposed the decline is due to reduced pneumococcal transmission or suppression of respiratory viruses, but the mechanism remains unclear. We undertook a secondary analysis of data collected from a clinical trial to evaluate the impact of NPIs on pneumococcal carriage and density, drivers of transmission and disease, during the COVID-19 pandemic in Ho Chi Minh City, Vietnam.

Prevention of young infant infections using oral azithromycin in labour in Fiji (Bulabula MaPei): study protocol of a randomised control trial.

Introduction: Infections are a leading cause of neonatal mortality globally and can be transmitted from mother-to-child vertically or horizontally. Fiji has higher rates of serious neonatal infections and infant skin and soft tissue infections (SSTIs) than high-income countries. Research from the Gambia found that a single dose of oral azithromycin in labour decreased bacterial carriage and infections in mothers and infants, particularly infant skin infections.

Social contacts and other risk factors for respiratory infections among internally displaced people in Somaliland.

Background: Populations affected by humanitarian crises experience high burdens of acute respiratory infections (ARI), potentially driven by risk factors for severe disease such as poor nutrition and underlying conditions, and risk factors that may increase transmission such as overcrowding and the possibility of high social mixing. However, little is known about social mixing patterns in these populations.

Methods: We conducted a cross-sectional social contact survey among internally displaced people (IDP) living in Digaale, a permanent IDP camp in Somaliland.

Effect of pneumococcal conjugate vaccine on prevalence of otitis media with effusion among children in Vietnam.

Purpose: Otitis media with effusion (OME) is common in young children and is associated with Streptococcus pneumoniae infection. We aimed to determine the impact of pneumococcal conjugate vaccine (PCV) introduction on the prevalence of OME and OME associated with vaccine-type (VT) or non-VT.

Methods: Population-based cross-sectional surveys were conducted in pre- (2016) and post-PCV periods (2017, 2018, and 2019) at selected communes in Nha Trang, Vietnam.

Variants of Streptococcus pneumoniae Serotype 14 from Papua New Guinea with the Potential to Be Mistyped and Escape Vaccine-Induced Protection.

Streptococcus pneumoniae (the pneumococcus) is a human pathogen of global importance, classified into serotypes based on the type of capsular polysaccharide produced. Serotyping of pneumococci is essential for disease surveillance and vaccine impact measurement. However, the accuracy of serotyping methods can be affected by previously undiscovered variants.

Association of pneumococcal carriage in infants with the risk of carriage among their contacts in Nha Trang, Vietnam: A nested cross-sectional survey.

Background: Infants are at highest risk of pneumococcal disease. Their added protection through herd effects is a key part in the considerations on optimal pneumococcal vaccination strategies. Yet, little is currently known about the main transmission pathways to this vulnerable age group.

Effectiveness of 13-valent pneumococcal conjugate vaccine against hypoxic pneumonia and hospitalisation in Eastern Highlands Province, Papua New Guinea: An observational cohort study.

Background: Pneumonia is a leading cause of childhood mortality with a major contributor. Pneumococcal conjugate vaccines (PCVs) have been introduced into immunisation programs in many low- to middle-income countries (LMICs) yet there is a paucity of data evaluating the effectiveness in these settings. We assess the effectiveness of 13-valent PCV (13vPCV) against hypoxic pneumonia, hospitalisation and other clinical endpoints in children <5 years living in Eastern Highlands Province, Papua New Guinea (PNG).

House Dust Mite Aeroallergen Suppresses Leukocyte Phagocytosis and Netosis Initiated by Pneumococcal Lung Infection.

Asthmatics are highly susceptible to developing lower respiratory tract infections caused by (SPN, the pneumococcus). It has recently emerged that underlying allergic airway disease creates a lung microenvironment that is defective in controlling pneumococcal lung infections. In the present study, we examined how house dust mite (HDM) aeroallergen exposure altered immunity to acute pneumococcal lung infection.