Reduction in Short-term Outpatient Consultations After a Campaign With Measles Vaccine in Children Aged 9–59 Months: Substudy Within a Cluster-Randomized Trial

Abstract

Background We assessed a measles vaccination campaign’s potential short-term adverse events. Methods In a cluster-randomized trial assessing a measles vaccination campaign’s effect on all-cause mortality and hospital admission among children aged 9–59 months in Guinea-Bissau, children received a measles vaccination (intervention) or a health check-up (control). One month to 2 months later, we visited a subgroup of children to ask mothers/guardians about outpatient consultations since enrollment. In log-binomial models, we estimated the relative risk (RR) of nonaccidental outpatient consultations. Results Among 8319 children (4437 intervention/3882 control), 652 nonaccidental outpatient consultations occurred (322 intervention/330 control). The measles vaccination campaign tended to reduce nonaccidental outpatient consultations by 16% (RR, 0.84 [95% confidence interval {CI}, .65–1.11]), especially if caused by respiratory symptoms (RR, 0.68 [95% CI, .42–1.11]). The reduction tended to be larger in children who prior to trial enrollment had a pentavalent vaccination (diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b) as the most recent vaccination (RR, 0.61 [95% CI, .42–.89]) than in children who prior to trial enrollment had a routine measles vaccination as the most recent vaccination (RR, 0.93 [95% CI, .68–1.26]) (P = .04 for interaction). Conclusions In the short term, a measles vaccination campaign seems not to increase nonaccidental outpatient consultations but may reduce them. Clinical Trials Registration NCT03460002.

Measles, mumps, and rubella vaccine at age 6 months and hospitalisation for infection before age 12 months: randomised controlled trial

“…Our findings corroborate the non-significant overall results of eight studies carried out in low income countries on the potential non-specific effects of standard titre measles vaccines on non-measles related hospitalisation and outpatient contacts. 10 11 17 22 23 25 27 28 One of these studies reported beneficial effects on hospital admissions in a subgroup analysis of girls (hazard ratio 0.59, 95% confidence interval 0.36 to 0.97). 10 No sex specific effects were, however, observed in the present trial.…”

“…Notably, randomised trials for outcomes of both overall mortality and morbidity consistently result in non-significant beneficial non-specific effects. 10 11 12 17 19 20 21 22 23 24 25 26 27 28 56 …”

“…However, based on our systematic review and meta-analysis of 22 randomised controlled trials testing the potential non-specific effects of measles vaccines, 5 6 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 no such beneficial effects were identified for non-measles related overall mortality or morbidity. A systematic review and meta-analysis published in 2016 came to the same conclusion.…”