Local discrepancies in measles vaccination opportunities: results of population-based surveys in Sub-Saharan Africa

Abstract

BackgroundThe World Health Organization recommends African children receive two doses of measles containing vaccine (MCV) through routine programs or supplemental immunization activities (SIA). Moreover, children have an additional opportunity to receive MCV through outbreak response immunization (ORI) mass campaigns in certain contexts. Here, we present the results of MCV coverage by dose estimated through surveys conducted after outbreak response in diverse settings in Sub-Saharan Africa.MethodsWe included 24 household-based surveys conducted in six countries after a non-selective mass vaccination campaign. In the majority (22/24), the survey sample was selected using probability proportional to size cluster-based sampling. Others used Lot Quality Assurance Sampling.ResultsIn total, data were collected on 60,895 children from 2005 to 2011. Routine coverage varied between countries (>95% in Malawi and Kirundo province (Burundi) while <35% in N’Djamena (Chad) in 2005), within a country and over time. SIA coverage was <75% in most settings. ORI coverage ranged from >95% in Malawi to 71.4% [95% CI: 68.9-73.8] in N’Djamena (Chad) in 2005.In five sites, >5% of children remained unvaccinated after several opportunities. Conversely, in Malawi and DRC, over half of the children eligible for the last SIA received a third dose of MCV.ConclusionsControl pre-elimination targets were still not reached, contributing to the occurrence of repeated measles outbreak in the Sub-Saharan African countries reported here. Although children receiving a dose of MCV through outbreak response benefit from the intervention, ensuring that programs effectively target hard to reach children remains the cornerstone of measles control.

Sub-national variation in measles vaccine coverage and outbreak risk: a case study from a 2010 outbreak in Malawi

“…Blantyre, which was prioritized based on R E , was the first district to receive vaccination campaigns (week 18) [ 2 ]. Although our estimates were calculated retrospectively, estimating vaccination coverage and susceptible birth cohort is possible before or during an outbreak [ 14 , 22 , 25 ] and could be used to allocate resources during an outbreak, such as the recent epidemic in the Democratic Republic of Congo [ 8 ]. Estimating R E before or during an outbreak is more difficult, generally requiring the use of models [ 17 ].…”

Description of a large measles epidemic in Democratic Republic of Congo, 2010–2013

“…Between 2010 and 2013, MSF conducted multiple household-based surveys in different areas of DRC, providing local information on vaccination coverage. Results of these surveys and their respective methodologies are reported elsewhere [ 12 , 13 ].…”

“…This data was exempt from review by the MSF Ethical Review Board (ERB) and the national ERB in Kinshasa as routinely collected data were used. During vaccine coverage surveys, verbal informed consent was obtained from each head of household visited [ 12 ]. Privacy and confidentiality of patients were ensured by ensuring that no identifying information was recorded.…”

Self-enforcing regional vaccination agreements

“…While many countries are adopting policies for universal coverage of childhood vaccines, vaccination coverage is far from universal in many locations and increasing coverage in those places will require more investment. There are particular disparities in local vaccination coverage in the case of measles in sub-Saharan Africa [56], especially in remote areas [57], making this system a good candidate for policy interventions that foster coalitions. Another example where a coalition approach would be useful is in funding immunization campaigns with the new meningococcal meningitis conjugate vaccine in the 25 countries of the African meningitis belt [58][59][60].…”