Why not think beyond preventing measles infection when measuring the impact of a measles vaccination campaign?
It is with great interest that we have read the BMJ news: ”Targeted measles and rubella vaccination campaign aims to stop global surge in cases” .
However, the impact of this campaign may go beyond targeting measles infection only and we therefore urge implementers and donors to take advantage of their unique situation to assess the wider impact on child health.
Over the past decades worldwide, all-cause child mortality has decreased tremendously  and billions of doses of the measles vaccine (MV) have been administered through campaigns . At the same time, accumulating evidence suggests that MV prevents mortality unrelated to measles infection; in other words, MV seems to have beneficial non-specific-effects . In an epidemiological review, commissioned by the World Health Organization, the authors have acknowledged that evidence is consistent on MV having beneficial non-specific effects on all-cause child mortality .
Thus, MV campaigns may have contributed to the decrease in all-cause child mortality beyond our common understanding [6, 7].
With the announced rollout of a measles and rubella vaccination campaign targeting 45 billion children in seven developing countries in the coming months , a unique opportunity arises to assess the impact of an MV campaign on all-cause child mortality.
With data from our health and demographic surveillance site (HDSS) in Guinea-Bissau, West Africa, we have previously taken advantage of ‘natural experiments’ arising when the Ministry of Health implements MV campaigns. In a before/after study among 8000 children, we found that all-cause child mortality was 20% lower after an MV campaign compared to the corresponding age group a year before the MV campaign (95%CI: 4%-34%), and that a large difference remained after censoring measles deaths (17% (95%CI: 0–31%)) . We also compared all-cause child mortality in MV campaign participants (5633) to non-participants (1006), which showed a markedly lower all-cause mortality in children who had received the MV campaign (72% (95%CI: 23–90%)); no deaths were measles related. Surprisingly, these reductions in all-cause mortality were stronger in children who had also received MV through the routine vaccination program [6, 7], which makes it less likely to explain the observed beneficial effects as caused merely by prevention of measles related deaths. Currently, we are pursuing these observations in a cluster-randomized controlled trial targeting about 18000 children aged 9-59 months in Guinea-Bissau .
The announced measles and rubella vaccination campaign could enable a prospective impact assessment using a massive sample size with great geographical diversity based on existing HDSS systems or the equivalent and/or through health facilities .
While the usual evaluation of coverage and post campaign measles mortality surveillance provides important information on the impact of an MV campaign , we emphasize a wider perspective, one that will hopefully encourage implementers and donors. An MV campaign may be much more efficient than assumed. However, to take advantage of its full potential, we need more research and thus, we should not miss the current unique opportunity. Perhaps, a future headline will state: ”Targeted measles vaccination campaign aims to reduce all-cause child mortality”?
Bandim Health Project, University of Southern Denmark (OPEN)
Competing interests: no competing interests
1. Mahase E. Targeted measles and rubella vaccination campaign aims to stop global surge in cases. BMJ 2020; 368:m473.
2. Hug L, Sharrow D, Zhong K, You D. Levels and Trends in Child Mortality. Report 2019. Estimates Developed by the UN Inter-agency Group for Child Mortality Estimation. 2019.
3. Orenstein WA, Cairns L, Hinman A, Nkowane B, Olivé J-M, Reingold AL. Measles and Rubella Global Strategic Plan 2012-2020 midterm review report: Background and summary. Vaccine 2018; 36 Suppl 1:A35-A42.
4. de Bree LCJ, Koeken V, Joosten LAB, et al. Non-specific effects of vaccines: Current evidence and potential implications. Semin Immunol 2018; 39:35-43.
5. Higgins JP, Soares-Weiser K, Lopez-Lopez JA, et al. Association of BCG, DTP, and measles containing vaccines with childhood mortality: systematic review. BMJ 2016; 355:i5170.
6. Fisker AB, Rodrigues A, Martins C, et al. Reduced All-cause Child Mortality After General Measles Vaccination Campaign in Rural Guinea-Bissau. Pediatr Infect Dis J 2015; 34:1369-76.
7. Byberg S, Thysen SM, Rodrigues A, et al. A general measles vaccination campaign in urban Guinea-Bissau: Comparing child mortality among participants and non-participants. Vaccine 2017; 35:33-9.
8. Varma A, Jensen AKG, Thysen SM, Pedersen LM, Aaby P, Fisker AB. Research protocol of two concurrent cluster-randomized trials: Real-life Effect of a CAMPaign with Measles Vaccination (RECAMP-MV) and Real-life Effect of a CAMPaign with Oral Polio Vaccination (RECAMP-OPV) on mortality and morbidity among children in rural Guinea-Bissau. BMC Public Health 2019; 19:1506.
9. Biai S, Rodrigues A, Nielsen J, Sodemann M, Aaby P. Vaccination status and sequence of vaccinations as risk factors for hospitalisation among outpatients in a high mortality country. Vaccine 2011; 29:3662-9.
10. KIT Royal Tropical Institute A. Measles campaigns and their effects on the overall immunization system. Available at: https://www.gavi.org/sites/default/files/document/measles-campaigns-in-n.... Accessed 02 March 2020.
Competing interests: No competing interests