Pneumococcal conjugate vaccine use during humanitarian crises

Streptococcus pneumoniae is a common human commensal that causes a sizeable part of the overall childhood mortality in low income settings. Populations affected by humanitarian crises are at especially high risk, because a multitude of risk factors that are enhanced during crises increase pneumococcal transmission and disease severity. Pneumococcal conjugate vaccines (PCVs) provide effective protection and have been introduced into the majority of routine childhood immunisation programmes globally, though several barriers have hitherto limited their uptake during humanitarian crises. When PCV coverage cannot be sustained during crises or when PCV has not been part of routine programmes, mass vaccination campaigns offer a quick acting and programmatically feasible bridging solution until services can be restored. However, we currently face a paucity of evidence on which to base the structure of such campaigns. We believe that, now that PCV can be procured at a substantially reduced price through the Humanitarian Mechanism, this lack of information is a remaining hurdle to PCV use in humanitarian crises. Considering the difficulties in conducting research in crises, we propose an evidence generation pathway consisting of primary data collection in combination with mathematical modelling followed by quasi-experimental evaluation of a PCV intervention, which can inform on optimal vaccination strategies that consider age targeting, dosing regimens and impact duration.

Impact and longevity of measles-associated immune suppression: a matched cohort study using data from the THIN general practice database in the UK

OBJECTIVE

To test the hypothesis that measles infection increases the incidence of non-measles infectious diseases over a prolonged period of time.

DESIGN

A population-based matched cohort study.

DATA SOURCES

This study examined children aged 1-15 years in The Health Improvement Network UK general practice medical records database. Participants included 2228 patients diagnosed with measles between 1990 and 2014, which were matched on age, sex, general practitioner practice and calendar year with 19 930 children without measles. All controls had received at least one measles vaccination. Children with a history of immune-compromising conditions or with immune-suppressive treatment were excluded.

PRIMARY OUTCOME MEASURES

Incidence rate ratio (IRR) of infections, anti-infective prescriptions and all-cause hospitalisations following measles in predetermined periods using multivariate analysis to adjust for confounding variables.

RESULTS

In children with measles, the incidence rate for non-measles infectious disease was significantly increased in each time period assessed up to 5 years postmeasles: 43% in the first month (IRR: 1.43; 95% CI 1.22 to 1.68), 22% from month one to the first year (IRR: 1.22; 95% CI 1.14 to 1.31), 10% from year 1 to 2.5 years (IRR: 1.10; 95% CI 1.02 to 1.19) and 15% (IRR: 1.15; 95% CI 1.06 to 1.25) in years 2.5 to 5 years of follow-up. Children with measles were more than three times as likely to receive an anti-infective prescription in the first month and 15%-24% more likely between the first month and 5 years. The rate of hospitalisation in children with measles was increased only in the month following diagnosis but not thereafter (IRR: 2.83; 95% CI 1.72 to 4.67).

CONCLUSION

Following measles, children had increased rates of diagnosed infections, requiring increased prescribing of antimicrobial therapies. This population-based matched cohort study supports the hypothesis that measles has a prolonged impact on host resistance to non-measles infectious diseases.

Baseline incidence of intussusception in early childhood before rotavirus vaccine introduction, the Netherlands, January 2008 to December 2012

Intussusception is a rare, potentially life-threatening condition in early childhood. It gained attention due to an unexpected association with the first rotavirus vaccine, RotaShield, which was subsequently withdrawn from the market. Across Europe, broad variations in intussusception incidence rates have been reported. This study provides a first estimate of intussusception incidence in young children in the Netherlands from 1 January 2008 to 31 December 2012, which could be used for future rotavirus safety monitoring. Our estimates are based on two different sources: electronic medical records from the primary healthcare database (IPCI), as well as administrative data from the Dutch hospital register (LBZ). The results from our study indicate a low rate of intussusception. Overall incidence rate in children < 36 months of age was 21.2 per 100,000 person-years (95% confidence interval (CI): 12.5–34.3) based on primary healthcare data and 22.6 per 100,000 person-years (95% CI: 20.9–24.4) based on hospital administrative data. The estimates suggest the upper and lower bound of the expected number of cases.

Patterns of spontaneous reports on narcolepsy following administration of pandemic influenza vaccine; a case series of individual case safety reports in Eudravigilance

OBJECTIVE

This study aims to describe the frequency and quality of spontaneous narcolepsy case reports following administration of pandemic influenza vaccine as captured in the Eudravigilance database.

METHODS

We conducted a retrospective descriptive study of spontaneous Individual Case Safety Reports (ICSRs), reporting narcolepsy following administration of pandemic influenza vaccine as received by Eudravigilance until July 2014. De-duplication was carried out by Eudravigilance. Frequency of reporting is described as number of ICSRs received per month over time. The quality of the ICSRs was evaluated by completeness of information and diagnostic certainty using the Automated Brighton Collaboration case definition tool (ABC-tool) for narcolepsy.

RESULTS

After de-duplication, a total of 1333 ICSRs of narcolepsy and/or cataplexy following pandemic influenza vaccine were identified, originating from 18 countries worldwide. Most of the ICSRs (61.9%) originated from the signaling countries, Sweden and Finland. Although de-duplication of case reports was carried out, it is suspected that many duplicates exist, in particular from Sweden. The majority of the ICSRs (95.3%), reported exposure to Pandemrix®. Only few reports were received for Arepanrix® (1.6%) or Focetria® (0.5%), and Celvapan® (0.1%). Of those ICSRs reporting age, 73.1% concerned persons below age of 20years. When using the ABC-tool, all ICSRs were classified as having insufficient information to meet the Brighton Collaboration case definition of narcolepsy.

CONCLUSION

An increase in reporting of narcolepsy appeared in Eudravigilance only after awareness was raised by the national authorities. Most narcolepsy reports were received from countries where the signal initially occurred, and were related to Pandemrix® in children/adolescents. Basic information about the patient and the exposure was present in most of the ICSRs. The ICSRs captured by Eudravigilance however, do not collect enough information to assess the diagnostic certainty according to the Brighton Collaboration case definition.