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Elife ; 102021 06 24.
Article in English | MEDLINE | ID: covidwho-1285537


Background: Childhood immunisation services have been disrupted by the COVID-19 pandemic. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic. Methods: We used two to three models per infection to estimate the health impact of 50% reduced routine vaccination coverage in 2020 and delay of campaign vaccination from 2020 to 2021 for measles vaccination in Bangladesh, Chad, Ethiopia, Kenya, Nigeria, and South Sudan, for meningococcal A vaccination in Burkina Faso, Chad, Niger, and Nigeria, and for yellow fever vaccination in the Democratic Republic of Congo, Ghana, and Nigeria. Our counterfactual comparative scenario was sustaining immunisation services at coverage projections made prior to COVID-19 (i.e. without any disruption). Results: Reduced routine vaccination coverage in 2020 without catch-up vaccination may lead to an increase in measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns in Ethiopia and Nigeria by a year may significantly increase the risk of measles outbreaks (both countries did complete their supplementary immunisation activities (SIAs) planned for 2020). For yellow fever vaccination, delay in campaigns leads to a potential disease burden rise of >1 death per 100,000 people per year until the campaigns are implemented. For meningococcal A vaccination, short-term disruptions in 2020 are unlikely to have a significant impact due to the persistence of direct and indirect benefits from past introductory campaigns of the 1- to 29-year-old population, bolstered by inclusion of the vaccine into the routine immunisation schedule accompanied by further catch-up campaigns. Conclusions: The impact of COVID-19-related disruption to vaccination programs varies between infections and countries. Planning and implementation of campaigns should consider country and infection-specific epidemiological factors and local immunity gaps worsened by the COVID-19 pandemic when prioritising vaccines and strategies for catch-up vaccination. Funding: Bill and Melinda Gates Foundation and Gavi, the Vaccine Alliance.

COVID-19/epidemiology , Immunization Programs/statistics & numerical data , Measles/prevention & control , Meningococcal Infections/prevention & control , Yellow Fever/prevention & control , Adolescent , Adult , Africa/epidemiology , Bangladesh/epidemiology , Child , Child, Preschool , Disease Outbreaks , Humans , Immunization Programs/methods , Infant , Measles/epidemiology , Measles Vaccine/therapeutic use , Meningococcal Infections/epidemiology , Meningococcal Vaccines/therapeutic use , Pandemics , Risk Assessment , SARS-CoV-2 , Vaccination/statistics & numerical data , Yellow Fever/epidemiology , Yellow Fever Vaccine/therapeutic use , Young Adult
Front Immunol ; 11: 575074, 2020.
Article in English | MEDLINE | ID: covidwho-1256374


Combined cellular and humoral host immune response determine the clinical course of a viral infection and effectiveness of vaccination, but currently the cellular immune response cannot be measured on simple blood samples. As functional activity of immune cells is determined by coordinated activity of signaling pathways, we developed mRNA-based JAK-STAT signaling pathway activity assays to quantitatively measure the cellular immune response on Affymetrix expression microarray data of various types of blood samples from virally infected patients (influenza, RSV, dengue, yellow fever, rotavirus) or vaccinated individuals, and to determine vaccine immunogenicity. JAK-STAT1/2 pathway activity was increased in blood samples of patients with viral, but not bacterial, infection and was higher in influenza compared to RSV-infected patients, reflecting known differences in immunogenicity. High JAK-STAT3 pathway activity was associated with more severe RSV infection. In contrast to inactivated influenza virus vaccine, live yellow fever vaccine did induce JAK-STAT1/2 pathway activity in blood samples, indicating superior immunogenicity. Normal (healthy) JAK-STAT1/2 pathway activity was established, enabling assay interpretation without the need for a reference sample. The JAK-STAT pathway assays enable measurement of cellular immune response for prognosis, therapy stratification, vaccine development, and clinical testing.

Dengue Virus/immunology , Immunity, Cellular , Orthomyxoviridae/immunology , Respiratory Syncytial Virus, Human/immunology , Rotavirus/immunology , Viral Vaccines/therapeutic use , Virus Diseases/immunology , Yellow fever virus/immunology , Biomarkers/blood , Dengue/blood , Dengue/immunology , Dengue/prevention & control , Dengue/virology , Dengue Vaccines/therapeutic use , Dengue Virus/pathogenicity , Diagnosis, Differential , Host-Pathogen Interactions , Humans , Immunogenicity, Vaccine , Influenza Vaccines/therapeutic use , Influenza, Human/blood , Influenza, Human/immunology , Influenza, Human/prevention & control , Influenza, Human/virology , Oligonucleotide Array Sequence Analysis , Orthomyxoviridae/pathogenicity , Predictive Value of Tests , RNA, Messenger/blood , RNA, Messenger/genetics , Respiratory Syncytial Virus Infections/blood , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/prevention & control , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/pathogenicity , Rotavirus/pathogenicity , Rotavirus Infections/blood , Rotavirus Infections/immunology , Rotavirus Infections/prevention & control , Rotavirus Infections/virology , Rotavirus Vaccines , Signal Transduction/genetics , Virus Diseases/blood , Virus Diseases/prevention & control , Virus Diseases/virology , Yellow Fever/blood , Yellow Fever/immunology , Yellow Fever/prevention & control , Yellow Fever/virology , Yellow Fever Vaccine/therapeutic use , Yellow fever virus/pathogenicity