Vaccine effectiveness against COVID-19: A test negative case-control study in Tunisia, August 2021

BACKGROUND

In response to the COVID-19 pandemic, multiple vaccines to protect against COVID-19 disease have been developed rapidly. Precise estimates of vaccine effectiveness (VE) vary according to studies design, outcomes measured and circulating variants. The aim of this study was to evaluate the anti-covid-19 vaccine effectiveness in Tunisia.

METHODS

We conducted a matched case-control study from 2nd to 15th August 2021. Cases and controls were subjects over 60 years of age, selected from the National testing database, regardless vaccine status. A standardized questionnaire was administered for cases and controls to collect information about vaccination status. For cases, vaccination status was defined based on the number of doses received before becoming ill and excludes doses received during the previous two weeks. For matched controls, a reference date based on the case's date of illness onset was defined in order to look at the control's vaccination status before its corresponding case became ill. The odds-ratio was calculated using simple conditional logistic regression. The VE (95 % confidence intervals) was calculated as (1 - odds ratio for vaccination) × 100 %.

RESULTS

A sample of 977 matched peers for age and Gender, were included between August 2, and August 15, 2021. The overall vaccine effectiveness (VE) was 70 % [95 % CI 62.8-75.8 %]. Among our sample, 68.1 % of the male population and 56.4 % of the female population were vaccinated with a VE of 73 % [95 % CI 62.9-80.3 %] and 67 % [95 % CI 55.8-75.3 %] respectively, regardless vaccine scheme (complete or incomplete). VE was higher for the age group [60-70 years[ (72.3 % [95 % CI 62.8-79.3 %]). VE was 77.6 % [95 % CI 70.9-82.8 %] to prevent both symptomatic and asymptomatic forms of the disease. Moreover, in prevention from severe forms (treated with oxygen-therapy or admission to an Intensive-care-unit) VE was 86.6 % [95 % CI 75.6-92.7 %] and 98.4 % [95 % CI [79.2-99.8 %] in prevention from COVID-19 deaths with a complete anti-Covid vaccination scheme.

CONCLUSION

The results of our study showed that the anti-Covid-19 vaccines used in Tunisia are efficient to prevent both SARS-COV-2 infections and severe forms related to the disease. This study provided important data on the performance of vaccines in real-world settings that guide decisions about vaccine sustained use.

Epidemiological patterns of Hepatitis A infection during the pre-vaccination Era: A population-based survey in Tunisia in 2015

BACKGROUND

In the 1980s, Tunisia was considered a country of high endemicity for Hepatitis A virus (HAV). Since 2000, an epidemiological shift has led to an increased incidence of symptomatic and severe forms of HAV infection.

OBJECTIVE

In 2015, we conducted a cross-sectional nationwide household-based HAV seroprevalence study in the total population regardless of age, sex, or geographical origin using a stratified sampling design in order to make an overview of the HAV epidemiological situation in Tunisia before vaccine implementation.

RESULTS

A total of 6322 individuals were enrolled. The HAV prevalence was 78.8%. The anti-HAV IgG seropositivity rate increases from 16% for ages 5-9 years to 45% for ages 10-14, 67% for ages 15-19, 87% for ages 20-24, and >90% for older age groups, which suggests an age at midpoint of population immunity (AMPI) in late adolescence. It was significantly higher in rural areas (p<10^-3) and varied significantly between and within regions (p<10^-4).

CONCLUSIONS

In this study, although the overall AMPI suggests intermediate endemicity, the regional AMPI varies from intermediate to very high endemicity profiles attributable to different socio-economic determinants and conditions of sanitation and hygiene. Also it provides insights for the best decisions in terms of vaccinations strategies.

Innovative Approaches to Improve Public Health Practice in the Eastern Mediterranean Region: Findings From the Sixth Eastern Mediterranean Public Health Network Regional Conference

Public health professionals in the Eastern Mediterranean region (EMR) have limited access to continuing education, including workshops and conferences in public health. Held under the theme Innovative Approaches: Adapting to the Current EMR Context, the Eastern Mediterranean Public Health Network (EMPHNET) organized and conducted the Sixth EMPHNET Regional Conference from March 26 to 29, 2018. This paper summarizes the key activities including workshops, roundtable discussions, oral and poster presentations, keynote speeches, and side meetings. Before the opening, 5 preconference workshops were held: “Field Epidemiology Training Program (FETP) Accreditation,” “Innovative Public Health Surveillance,” “Human and Animal Brucellosis,” “Rapid Response Teams,” and “Polio Transition and Routine Immunization.” The conference hosted 6 roundtable discussions: “Consolidation of the FETP Network,” “One Health to Achieve Global Health Security,” “Polio Eradication Efforts and Transition Planning for Measles Elimination,” “Mobile Data Collection and Other Innovative Tools to Enhance Decision Making,” “Confronting Candida auris: An Emerging Multidrug-resistant Global Pathogen,” and “Functioning and Sustainable Country Public Health Emergency Response Operation Framework.” One of the conference’s key objectives was to provide a space for FETP residents, graduates, and public health professionals to showcase achievements. A total of 421 abstracts were submitted and after professional review, 34.9% (147/421) were accepted (111 for oral presentations and 36 for poster presentations) and published by Iproceeding. The conference met the primary objectives of showcasing the public health accomplishments and contributions of the EMR, encouraging the exchange of ideas and coordination among stakeholders, and engaging cross-sectoral workforce in producing recommendations for approaching regional and global health concerns. Moreover, the conference presented a unique opportunity for FETPs and other public health professionals from the Mediterranean region to present their significant scientific work and also facilitated networking among professionals. EMPHNET strives to continue to present similar exchange opportunities for public health professionals in the region.