BACKGROUND: The COVID-19 pandemic had a profound impact on healthcare systems and services, including routine immunization (RI). To date, there is limited information on the effects of the COVID-19 pandemic on RI in West African countries such as Sierra Leone, which had already experienced public health emergencies that disrupted its healthcare system. Here, we describe the impact of the COVID-19 pandemic on the RI of key antigens in Sierra Leone.
METHODS: We used vaccination data from the District Health Information System for BCG, measles-rubella 1 and 2, and pentavalent 1 and 3 antigens. We compared 2019, 2020, 2021, and 2022 annual coverage rates for the selected antigens at the national and district levels. We used the Pearson chi-square test to assess the difference between annual coverage rates between 2019 and 2020, 2020-2021, and 2021-2022.
RESULTS: National coverage rates for all antigens declined in 2019-2020, notably measles-rubella 1 and pentavalent 3 (-5.4% and - 4.9%). Between 2020 and 2021, there was an overall increase in coverage (+ 0.2% to + 2.5%), except for measles-rubella 2 (-1.8%). Measles-rubella antigens rebounded in 2021-2022, while others decreased between - 0.5 and - 1.9% in coverage. Overall, all district-level coverage rates in 2022 were lower than those in 2019. Most districts decreased between 2019 and 2022, though a few had a continuous increase; some had an increase/recovery between 2020 and 2021; some districts had recovered 2019 levels by 2022.
CONCLUSIONS: The COVID-19 pandemic impacted Sierra Leone\'s national BCG, measles-rubella, and pentavalent antigen immunization, which were not fully restored in 2022. Most districts experienced notable coverage declines during the pandemic, though a few reached or surpassed 2019 rates in 2022. Examining pandemic impact can benefit from a focus beyond the national level to identify vulnerable regions. Sierra Leone\'s post-pandemic RI reestablishment needs targeted strategies and continual investments for equitable access and coverage, as well as to prevent vaccine-preventable diseases.

Following the 2015 earthquake, a measles-rubella (MR) supplementary immunization activity (SIA), in four phases, was implemented in Nepal in 2015-2016. A post-campaign coverage survey (PCCS) was then conducted in 2017 to assess SIA performance and explore factors that were associated with vaccine uptake.
A household survey using stratified multi-stage probability sampling was conducted to assess coverage for a MR dose in the 2015-2016 SIA in Nepal. Logistic regression was then used to identify factors related to vaccine uptake.
Eleven thousand two hundred fifty-three households, with 4870 eligible children provided information on vaccination during the 2015-2016 MR SIA. Overall coverage of measles-rubella vaccine was 84.7% (95% CI: 82.0-87.0), but varied between 77.5% (95% CI: 72.0, 82.2) in phase-3, of 21 districts vaccinated in Feb-Mar 2016, to 97.7% (CI: 95.4, 98.9) in phase-4, of the last seven mountainous districts vaccinated in Mar-Apr 2016. Coverage in rural areas was higher at 85.6% (CI: 81.9, 88.8) than in urban areas at 79.0% (CI: 75.5, 82.1). Of the 4223 children whose caregivers knew about the SIA, 96.5% received the MR dose and of the 647 children whose caregivers had not heard about the campaign, only 1.8% received the MR dose.
The coverage in the 2015-2016 MR SIA in Nepal varied by geographical region with rural areas achieving higher coverage than urban areas. The single most important predictor of vaccination was the caregiver being informed in advance about the vaccination campaign. Enhanced efforts on social mobilization for vaccination have been used in Nepal since this survey, notably for the most recent 2020 MR campaign.

We present an extremely rare case of rubella that developed after rubella vaccine administration. A 54-year-old man complained of back and neck pain for some days. He presented with generalized rash and arthralgia that had persisted for two days before his visit. His vital signs were normal, and arthralgia had disappeared during an examination, but lymphadenopathy in the left posterior neck and pink papules were observed throughout the body. He had received his first Rubella vaccination 17 days before this visit and had attended a crowded festival. Owing to the rubella epidemic in that prefecture, we performed a rubella antibody test and polymerase chain reaction assay using blood, urine, and pharyngeal swab specimens. Rubella IgG and IgM antibody titers were 3 and 1.48, respectively. The pharyngeal swab yielded positive results for the 1a vaccine strain. Therefore, he was diagnosed with rubella due to rubella vaccination. His symptoms improved eventually. His clinical course was uncomplicated. Symptoms resolved within one week without specific treatment. The vaccine rubella strain is not as highly infectious as wild-type rubella strains. If rubella symptoms appear after vaccination, it must be investigated whether these are vaccine-specific adverse reactions, wild-strain rubella onset, or other eruptive viral infections.

Globally, measles remains a major cause of child mortality, and rubella is the leading cause of birth defects among all infectious diseases. In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan that set a target to eliminate Measles-Rubella (MR) in five of the six World Health Organization (WHO) regions by 2020. This was cross-sectional study employed both quantitative and qualitative research methods. The sample size was calculated to provide overall, age- and sex-specific coverage estimates for MR vaccine among children aged between 9 and 59 months at the national level. Using desired precision of ±5% with an expected coverage of 95%, a total of 15,235 households were required. The age of children, a child who had received the MR vaccine before the campaign, household wealth quintile, the age of caregivers, and their marital status were associated with non-coverage of MR vaccination among children aged 9-59 months in Tanzania. Nationally, an estimated 88.2% (95% CI: 87.3-89%) of children aged 9-59 months received the MR campaign dose, as assessed by caregivers\' recall. These estimates revealed slightly higher coverage in Zanzibar 89.6% (95% CI: 84.7-93%) compared to Mainland Tanzania 88.1% (95% CI 87.2-88.9%). These associated factors revealed causes of unvaccinated children and may be some of the reasons for Tanzania\'s failure to meet the MR campaign target of 95 percent vaccination coverage. Thus, vaccine development must increase programmatic oversight in order to improve immunization activities and communication strategies in Tanzanian areas with low MR coverage.

UNASSIGNED: in 2014, Tanzania introduced the combined measles-rubella vaccine in the routine immunization schedule. Two doses of measles-rubella vaccine (MR1 and MR2) are recommended at 9 and 18 months, respectively. In 2015, MR2 coverage among eligible 18-month-old children in Tanzania was only 57%, lower than the WHO-recommended coverage (95%). During the same period Mtwara District Council (MDC) reported a coverage of 52% which is lower than the nation average. We determined factors associated with non-uptake of MR2 among children in MDC Tanzania.
UNASSIGNED: we conducted a community-based cross-sectional survey using cluster sampling during January - April 2017 in MDC. Caretakers of children born during January 2014 - January 2015 and residing in MDC for the past three years were recruited. We interviewed participants and reviewed vaccination cards. Logistic regression modeling was employed to identify independent factors associated with uptake of MR2.
UNASSIGNED: of 1,000 children assessed, 558 (55.8%) were unvaccinated with MR2. Factors independently associated with non-uptake of MR2 included the caretaker being unaware of the ages for MR1 and MR2 administration [aOR=3.50; 95%CI 1.98-6.21; p<0.001], having MR2 vaccination services offered at the local vaccination station fewer than three days per week [aOR=1.50; 95%CI 1.42-5.59; p<0.001], not having the vaccine available during vaccination days [aOR=3.38; 95%CI 1.08-10.61; p<0.01], unwillingness of health workers to open multi-dose vaccine vials for a single child [aOR=3.80; 95% CI 2.12-6.79; p<0.001], and long waiting times for vaccination services [aOR=1.80; 95% CI 1.08-3.00; p<0.01].
UNASSIGNED: more than half the children under five years in MDC were not vaccinated with MR2. Lack of caretaker knowledge about appropriate vaccination age, unavailability of vaccine, having insufficient numbers of children waiting to warrant multidose vial use, and long clinic waiting times were associated with MR2 non-uptake. The community should receive education about MR vaccine; we recommend thorough screening of children?s vaccination status at each clinic visit and provision of vaccine whenever possible. Vaccine distribution should be improved in MDC.

Frequently, a country will procure a single vaccine vial size, but the question remains whether tailoring the use of different size vaccine vial presentations based on populations or location characteristics within a single country could provide additional benefits, such as reducing open vial wastage (OVW) or reducing missed vaccination opportunities.
Using the Highly Extensible Resource for Modeling Supply Chains (HERMES) software, we built a simulation model of the Zambia routine vaccine supply chain. At baseline, we distributed 10-dose Measles-Rubella (MR) vials to all locations, and then distributed 5-dose and 1-dose MR vials to (1) all locations, (2) rural districts, (3) rural health facilities, (4) outreach sites, and (5) locations with average MR session sizes <5 and <10 children. We ran sensitivity on each scenario using MR vial opening thresholds of 0% and 50%, i.e. a healthcare worker opens an MR vaccine for any number of children (0%) or if at least half will be used (50%).
Replacing 10-dose MR with 5-dose MR vials everywhere led to the largest reduction in MR OVW, saving 573,892 doses (103,161 doses with the 50% vial opening threshold) and improving MR availability by 1% (9%). This scenario, however, increased cold chain utilization and led to a 1% decrease in availability of other vaccines. Tailoring 5-dose MR vials to rural health facilities or based on average session size reduced cold transport constraints, increased total vaccine availability (+1%) and reduced total cost per dose administered (-$0.01) compared to baseline.
In Zambia, tailoring 5-dose MR vials to rural health facilities or by average session size results in the highest total vaccine availability compared to all other scenarios (regardless of OVT policy) by reducing open vial wastage without increasing cold chain utilization.

Involvement of the central nervous system is common in measles, but rare in rubella. However, rubella virus (RV) can cause a variety of central nervous system syndromes, including meningitis, encephalitis, Guillain-Barré syndrome and sub acute sclerosing panencephalitis. We report the occurrence of one fatal case of the encephalitis associated with measles-rubella (MR) vaccine during an immunization campaign in São Paulo, Brazil. A 31 year-old-man, previously in good health, was admitted at emergency room, with confusion, agitation, inability to stand and hold his head up. Ten days prior to admission, he was vaccinated with combined MR vaccine (Serum Institute of India) and three days later he developed \'flu-like\' illness with fever, myalgia and headache. Results of clinical and laboratory exams were consistent with a pattern of viral encephalitis. During hospitalization, his condition deteriorated rapidly with tetraplegia and progression to coma. On the 3rd day of hospitalization he died. Histopathology confirmed encephalitis and immunohistochemistry was positive for RV on brain tissue. RV was also detected by qPCR and virus isolation in cerebrospinal fluid, brain and other clinical samples. The sequence obtained from the isolated virus was identical to that of the RA 27/3 vaccine strain.