Archives

  • 2018-07
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • With the publication of this month s

    2019-05-15

    With the publication of this month\'s issue, we mark \'s first birthday. I hope you will allow me to effuse for a moment in the manner of a new parent discovering the fascination of her offspring\'s everyday achievements… Since its conception in March, 2013, the infant has maintained a healthy intake of submissions, with an average of 72 per month and a total of more than 1000 to date. Its diet has been varied, ranging from noma in Niger to sexual violence in Asia-Pacific, with this nutritious fodder being sourced from a total of 79 countries (luckily air miles were saved by cunning use of online delivery vehicles). Baby hit all of its developmental milestones, having published 52 original research articles, 101 commentaries, and 61 letters to the editor in its first 12 months. Additionally, in a display of astonishing (to its parent) precociousness, its conjoined twin, Blog, published 50 posts—all bar four of which were spontaneously submitted. Finally, if you\'ll permit me to labour a metaphor for one more paragraph, because \'s progress can be followed without the need to pay to join an exclusive community (ie, to buy a subscription), family (researchers), friends (readers), and wellwishers (everyone else) have been generous in their support: the journal has more than 6000 Twitter followers and almost 30 000 individuals signed up for new content alerts, and saw nearly 183 500 full-text downloads over the past year. I am tremendously grateful for the confidence shown in the journal so far and am excited to join \'s supporters in anticipating the coming years of publishing influential research and thought-provoking commentary.
    Why is herd protection from pneumococcal disease important? The pneumococcus is the leading cause of death in children worldwide, and children who die are likely to be those who are unable to access lifesaving thyrotropin releasing hormone and pneumococcal conjugate vaccine (PCV). However, if vaccination of other children in the community stops transmission of the serotypes in the vaccine, then protection is provided to those most at risk of mortality, even if they are not given the vaccine themselves. The immunisation of infants with PCV in developed countries extends protection beyond direct protection of the immunised infants, to include children too young to be immunised, adults with substantial risk of pneumococcal disease such as those infected by HIV, and older people. Indeed, the cost-effectiveness of PCV is such that in developed countries, despite the high cost of the vaccine, herd protection means use of the vaccine is cost saving. More than 90% of hospital admissions averted by the vaccine in developed countries occur in unimmunised adults, who are indirectly protected by the cessation of transmission to them of the serotypes in the vaccine. Do these herd benefits exist in developing countries and how best can we study herd protection in settings that do not have microbiological confirmation of invasive pneumococcal disease, much less the serotyping of isolated strains, and also do not have electronic International Classification of Diseases to record pneumonia hospital admissions and deaths? The first part of the question—do herd benefits exist in developing countries—is being answered by a series of reports that consistently suggest that the rollout of PCV in Africa seems to be associated with reductions in transmission of vaccine-type pneumococci in the community. In a trial of 7-valent PCV (PCV7) in The Gambia, and after PCV7 rollout in a 6-week, 14-week, and 9-month schedule in rural South Africa, reductions in carriage of vaccine types were found in unimmunised children and adults in the community. In Laura Hammitt and colleagues extend these data to PCV10 and show that in the coastal demographic surveillance area around Kilifi, Kenya, where PCV10 was introduced in January, 2011, a reduction in nasopharyngeal carriage of vaccine serotypes occurred not only in immunised children, but also in unimmunised children and adults over the next 2 years. To speed up the prospect of herd protection from PCV10 in the area, children younger than 5 years were offered the vaccine. Carriage of vaccine types was reduced by 66% (95% CI 38–82) in unimmunised children and adults at least 5 years old. Was the catch-up immunisation of children 12–59 months old the key to the rapid appearance of herd protection in older age groups? A similar level of reduction in carriage (61%) among unvaccinated children 1–5 years old was noted in the same 2 years after PCV10 introduction in Kenya without catch-up, in an urban slum, suggesting that perhaps the key vaccine-type pneumococcal transmitters are probably younger than 2 years.