Insights from a modelling analysis of COVID-19 vaccination in the Eastern Mediterranean Region.

Background: Understanding the main determinants of COVID-19 vaccine uptake is critical to increasing vaccine coverage. This is particularly important for COVID-19 vaccine uptake, which has been affected by both demand and supply issues. Aim: To understand the links between vaccine uptake and demand and supply issues in the WHO Eastern Mediterranean and UNICEF Middle East and North Africa regions. Methods: We collected data through 2 rounds of a repeated cross-sectional phone survey from 11 000 individuals across 16 low- and middle-income countries. We used logit modelling to distil the main characteristics of the 4 vaccination categories (vaccinated, unvaccinated but willing, unvaccinated and undecided, and unvaccinated and unwilling) while also considering vaccine availability. We conducted sub-regional analysis to account for differences in level of development between the low- and middle-income countries. Results: Despite the increase in vaccination coverage from 60.9% at the end of 2021 to 78.3% by August 2022, about 9% were not willing and were not vaccinated during the two rounds of interviews. Our modelling analysis revealed that positive beliefs about safety, effectiveness and side effects of the COVID-19 vaccines were associated with increased odds of being vaccinated or willingness to be vaccinated. Those who did not believe in the safety of the vaccines were less likely to be vaccinated than those who believed in the safety of the vaccines (OR: 0.56; 95% CI: 0.46-0.67). By contrast, negative beliefs about the COVID-19 vaccines increased the probability of being unwilling to be vaccinated. Conclusion: The results from this research offer useful insights into tackling the supply and demand related barriers to COVID-19 vaccination uptake and provides lessons for future health threats.

Maiden immunization coverage survey in the republic of South Sudan: a cross-sectional study providing baselines for future performance measurement.

INTRODUCTION: Since the comprehensive peace agreement was signed in 2005, institutionalization of immunization services in South Sudan remained a priority. Routine administrative reporting systems were established and showed that national coverage rates for DTP-3 rose from 20% in 2002 to 80% in 2011. This survey was conducted as part of an overall review of progress in implementation of the first EPI Multi-Year Plan for South Sudan 2007-2011. This report provides maiden community coverage estimates for immunization. METHODS: A cross sectional community survey was conducted between January and May 2012. Ten cluster surveys were conducted to generate state-specific coverage estimates. The WHO 30x7 cluster sampling method was employed. Data was collected using pre-tested, interviewer guided, structured questionnaires through house to house visits. RESULTS: The fully immunized children were 7.3%. Coverage for specific antigens were; BCG (28.3%), DTP-1(25.9%), DTP-3 (22.0%), Measles (16.8%). The drop-out rate between the first and third doses of DTP was 21.3%. Immunization coverage estimates based on card and history were higher, at 45.7% for DTP-3, 45.8% for MCV and 32.2% for full immunization. Majority of immunizations (80.8%) were received at health facilities compared to community service points (19.2%). The major reason for missed immunizations was inadequate information (41.1%). CONCLUSION: The proportion of card-verified, fully vaccinated among children aged 12-23 months is very low at 7.3%. Future efforts to improve vaccination quality and coverage should prioritize training of vaccinators and program communication to levels equivalent or higher than investments in EPI cold chain systems since 2007.

Tanzania national survey on iodine deficiency: impact after twelve years of salt iodation.

BACKGROUND: In many low-income countries, children are at high risk of iodine deficiency disorders, including brain damage. In the early 1990s, Tanzania, a country that previously suffered from moderate to severe iodine deficiency, adopted universal salt iodation (USI) as an intervention strategy, but its impact remained unknown. METHODS: We report on the first national survey in mainland Tanzania, conducted in 2004 to assess the extent to which iodated salt was used and its apparent impact on the total goitre prevalence (TGP) and urinary iodine concentrations (UIC) among the schoolchildren after USI was initiated. In 2004, a cross-sectional goitre survey was conducted; covering 140,758 schoolchildren aged 6 - 18 years were graded for goitre according to new WHO goitre classification system. Comparisons were made with district surveys conducted throughout most of the country during the 1980s and 90s. 131,941 salt samples from households were tested for iodine using rapid field test kits. UIC was determined spectrophotometrically using the ammonium persulfate digestion method in 4523 sub-sampled children. RESULTS: 83.6% (95% CI: 83.4 - 83.8) of salt samples tested positive for iodine. Whereas the TGP was about 25% on average in the earlier surveys, it was 6.9% (95%CI: 6.8-7.0) in 2004. The TGP for the younger children, 6-9 years old, was 4.2% (95%CI: 4.0-4.4), n = 41,965. In the 27 goitre-endemic districts, TGP decreased from 61% (1980s) to 12.3% (2004). The median UIC was 204 (95% CF: 192-215) microg/L. Only 25% of children had UIC <100 microg/L and 35% were > or = 300 microg/L, indicating low and excess iodine intake, respectively. CONCLUSION: Our study demonstrates a marked improvement in iodine nutrition in Tanzania, twelve years after the initiation of salt iodation programme. The challenge in sustaining IDD elimination in Tanzania is now two-fold: to better reach the areas with low coverage of iodated salt, and to reduce iodine intake in areas where it is excessive. Particular attention is needed in improving quality control at production level and perhaps the national salt iodation regulations may need to be reviewed.