Correlating IgG Levels with Neutralising Antibody Levels to Indicate Clinical Protection in Healthcare Workers at Risk during a Measles Outbreak.

The rapid transmission of measles poses a great challenge for measles elimination. Thus, rapid testing is required to screen the health status in the population during measles outbreaks. A pseudotype-based virus neutralisation assay was used to measure neutralising antibody titres in serum samples collected from healthcare workers in Sheffield during the measles outbreak in 2016. Vesicular stomatitis virus (VSV) pseudotypes bearing the haemagglutinin and fusion glycoproteins of measles virus (MeV) and carrying a luciferase marker gene were prepared; the neutralising antibody titre was defined as the dilution resulting in 90% reduction in luciferase activity. Spearman's correlation coefficients between IgG titres and neutralising antibody levels ranged from 0.40 to 0.55 (p < 0.05) or from 0.71 to 0.79 (p < 0.0001) when the IgG titres were obtained using different testing kits. In addition, the currently used vaccine was observed to cross-neutralise most circulating MeV genotypes. However, the percentage of individuals being "well-protected" was lower than 95%, the target rate of vaccination coverage to eliminate measles. These results demonstrate that the level of clinical protection against measles in individuals could be inferred by IgG titre, as long as a precise correlation has been established between IgG testing and neutralisation assay; moreover, maintaining a high vaccination coverage rate is still necessary for measles elimination.

Measles outbreak in sub-Saharan Africa amidst COVID-19: A rising concern, efforts, challenges, and future recommendations.

In Sub-Saharan Africa, the number cases of Measles have spiked by 400%, some of the countries affected being Ethiopia, Somalia and Democratic Republic of the Congo. This is due to the emergence of COVID-19 which has disrupted the global fight against Measles by impairing the routine immunization programs. This has led to suspension of the measles vaccination drive, where about 23 million children missed out on all basic childhood vaccines including Measles-Mumps-Rubella vaccine in Sub-Saharan Africa. Despite the efforts to conduct mass immunization campaign for Measles in some countries, there is a need to build stronger health systems that would provide education to promote awareness and commitment to routine Measles vaccination and provide Vitamin A supplements to boost immunity.

Non-COVID-19 vaccine hesitancy among migrant populations worldwide: a scoping review of the literature, 2000-2020.

INTRODUCTION: Migration can be linked to the transmission of vaccine-preventable diseases. Hence, monitoring migrants' vaccination-related concerns can inform needed interventions to support vaccine acceptance. AREAS COVERED: Along with Google and Google Scholar, we searched 13 bibliographic databases between 1 January 2000 and 10 October 2020, to identify published studies of vaccine hesitancy among migrant populations. From a total of 8,915 records, we screened 745 abstracts and included 112 eligible articles. We summarized extracted data using figures, tables, and narrations. Of the 112 articles, 109 were original quantitative (48%), qualitative (45%), and mixed-methods (7%) research, originating mainly from the United States (US) (68%), the United Kingdom (UK) (12%), and Scandinavia (6%). Most articles addressed human papillomavirus (63%), measles (13%), and influenzas (9%) vaccinations, and the leading sponsor of funded research was the US National Institutes of Health (50%). Discernable migrant groups with vaccine-specific concerns included Somali diasporas, UK-based Poles and Romanians, and US-based Haitians and Koreans. Among US-based Latina/Latino immigrants, lower vaccine uptake frequency was mostly associated with awareness levels, knowledge gaps, and uninsured status. EXPERT OPINION: Migrants' vaccine-related apprehensions may cascade well beyond their proximate social connections and influence vaccine attitudes and behaviors in their countries-of-origin.

Measles outbreak investigation in Aweil East county, South Sudan.

During January 2018-June 2020, Aweil East confirmed five measles outbreaks. In March 2020, Aweil East reported twenty measles IgM+ cases. Before this outbreak, Aweil East had confirmed an outbreak in late November 2019. Even after conducting outbreak reactive vaccinations (ORV) in December 2019 and February 2020, measles spread was not interrupted. The nationally supported measles follow-up campaign (MFUC) conducted in late February 2020 was deferred in Aweil East because of the February ORV. We reviewed the measles data collected through passive and active surveillance. A matched case-control study was conducted to evaluate potential exposures. Face-to-face interviews with cases and controls using a semi-structured questionnaire were used to collect demographics, disease, and exposures related data. A total of 687 cases with eight deaths; attack and case fatality rate of 123/100,000 population and 1.16%, respectively. Among the cases, 51.8% were male, the median age was four years, and 59% of cases ≥9 months were unvaccinated. Eighty point six percent (80.6%) of cases reported after the February ORV were unvaccinated. The outbreak peaked in late March 2020. Unvaccinated persons had higher odds of getting measles (adjusted odds ratio (AOR)=8.569; 95% CI [1.41- 53.4], p=0.02). Non exposed persons had a lower odd of getting measles (AOR=0.114; 95% CI [0.02-0.61], p=0.011). During 2018-2019, the accumulated number of unvaccinated children (18,587) is more than a birth cohort of the county. Persistent low routine vaccination is the most critical driver of the measles outbreaks. Low-quality ORV and the intermediate population density are secondary drivers of the outbreaks.