Vaccine最新文献

{"title":"Effectiveness of COVID-19 vaccine against SARS-CoV-2 infection among symptomatic COVID-19 patients in Uganda","authors":"Andrew M. Abaasa,&nbsp;Sylvia Kusemererwa,&nbsp;Violet Ankunda,&nbsp;Terry A. Ongaria,&nbsp;Bernadette Nayiga,&nbsp;Ayoub Kakande,&nbsp;Deogratius Ssemwanga,&nbsp;Geofrey Kimbugwe,&nbsp;Henry K. Bosa,&nbsp;Yonas T. Woldemariam,&nbsp;Annet Kisakye,&nbsp;James Humphreys,&nbsp;Archibald K. Worwui,&nbsp;Sandra Cohuet,&nbsp;Jason M. Mwenda,&nbsp;Alison M. Elliott,&nbsp;Pontiano Kaleebu,&nbsp;Eugene Ruzagira","doi":"10.1016/j.vaccine.2025.126976","DOIUrl":"10.1016/j.vaccine.2025.126976","url":null,"abstract":"<div><h3>Background</h3><div>COVID-19 vaccines significantly reduce severe disease outcomes, but uncertainty remains about long-term protection. We investigated vaccine effectiveness (VE) against SARS-CoV-2 infection over extended periods in the World Health Organisation AFRO-MoVE network studies in Africa.</div></div><div><h3>Methods</h3><div>Participants with COVID-19-like symptoms were recruited between 2023 and 2024 for a test-negative case-control study conducted across 19-healthcare centres in Uganda. Cases were symptomatic patients with any three of cough, sore-throat, coryza, among others, and PCR-confirmed SARS-CoV-2, while controls were SARS-CoV-2 PCR-negative. Vaccination was verified from vaccination cards, hospital-records, vaccination registry and self-reporting. VE was assessed through three measures: (a) Annual - patients vaccinated in the past 12-months regardless of dose vs those vaccinated &gt;12-months before symptom onset plus unvaccinated; (b) Absolute - patients vaccinated in the past 12-months vs unvaccinated; and (c) Relative - patients vaccinated in the past 12-months vs those vaccinated &gt;12-months before symptom onset. VE was calculated as 1- adjusted odds ratio for three patient groups based on days since the last dose; (1) &lt;365, (2) 7–269 and (3) 270–364 while adjusting for age, sex, calendar-time and chronic conditions. The sensitivity analysis excluded patients that were previously infected with SARS-CoV-2.</div></div><div><h3>Findings</h3><div>In total, 1371 patients, 56 % female were recruited. Of these, 173 were classified as cases, with 97 (56 %) fully vaccinated compared to 701 (59 %) controls, <em>p</em> = 0.830. The overall adjusted VE was moderate, 45 % to 59 %, and remained consistent across the annual, absolute and relative measures. Sensitivity analysis showed consistently lower VE (32 % to 38 %) across all measures.</div></div><div><h3>Interpretation</h3><div>The results suggest that COVID-19 vaccination provides moderate protection against symptomatic SARS-CoV-2 infection up to 12-months after the last dose and highlight the importance of up-to-date vaccinations for high-risk individuals. The lack of clear COVID-19 seasonality in this and other African settings creates a challenge to selecting the optimal timing for annual vaccination.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 126976"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143588817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of BNT162b2 and Ad26.COV2.S vaccines against COVID-19-related hospitalisation amongst adult members of a private health insurance plan in South Africa during the Delta and Omicron periods: A test-negative case-control study","authors":"Siobhan L. Johnstone,&nbsp;Daniel Shapiro,&nbsp;Nicola Chiwandire,&nbsp;Lundi Matoti,&nbsp;Carmen Whyte,&nbsp;Jolene Bultinck-Human,&nbsp;Selaelo Mametja,&nbsp;Craig Getz,&nbsp;Boldwin Moyo,&nbsp;Mabatlo Semenya,&nbsp;Sibongile Walaza,&nbsp;Cheryl Cohen,&nbsp;Michelle J. Groome","doi":"10.1016/j.vaccine.2025.127068","DOIUrl":"10.1016/j.vaccine.2025.127068","url":null,"abstract":"<div><h3>Background</h3><div>COVID-19 vaccine effectiveness estimates from Africa are limited. These data can guide decisions on selecting priority groups in vaccine programs. This study estimated VE for BNT162b2 and Ad26.COV2.S against COVID-19-related hospitalisation, stratified by age group, time since vaccination, and HIV-infection status for three SARS-CoV-2 surges in South Africa.</div></div><div><h3>Methods</h3><div>We applied a test-negative case-control design to hospitalisations for acute respiratory infections amongst members of a medical insurance plan during the delta (9 May 2021–18 September 2021), omicron BA.1 (28 November 2021–5 February 2022), and BA.4/5 (17 April 2022–28 May 2022) variant periods. All data, including vaccination history, were extracted from insurance plan claims. Logistic regression models adjusted for age, comorbidities, time since vaccination, income level and documentation of previous SARS-CoV-2 infection, were used to calculate VE.</div></div><div><h3>Results</h3><div>BNT162b2 was protective against COVID-19-related hospitalisation for all variant periods (VE 89.3 % (95 % CI, 85.9–91.9) for delta, reduced to 31.4 % (95 % CI, 19.1–41.9) and 22.7 % (95 % CI, 2.2–38.9) for omicron BA.1, and BA.4/5 respectively). VE estimates for Ad26.COV2·S, although lower than BNT162b2, were protective for all periods (48.8 % (95 % CI, 39.6–56.5), 19.8 % (95 % CI, 5.8–31.6), and 45.0 % (95 % CI, 29.8–57.0) for delta, omicron BA.1, and BA.4/5 respectively). Protection against severe infection was shown in those ≥60 years and younger age groups, as well as in people living with HIV (PLWH) and HIV-uninfected individuals.</div></div><div><h3>Conclusion</h3><div>Vaccination offered significant protection against COVID-19-related hospitalisation in PLWH and the elderly, and is therefore an effective means of reducing severe outcomes in these high-risk populations in South Africa. VE against BA.4/5 waned with time since vaccination suggesting boosters may be necessary.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 127068"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COVID-19 vaccine effectiveness against severe acute respiratory infections (SARI) hospitalisations associated with laboratory-confirmed SARS-CoV-2 in Ghana, June 2022 to March 2024","authors":"Nicholas Amoako,&nbsp;Sandra Cohuet,&nbsp;Michael Rockson Adjei,&nbsp;Celine Gurry,&nbsp;Abraham Oduro,&nbsp;Prince Darko Agyapong,&nbsp;Osei Musah,&nbsp;Ivy Asantewaa Asante,&nbsp;Anthony Afum-Adjei Awuah,&nbsp;Reuben Ayivor-Djanie,&nbsp;Kwabena Obeng Duedu,&nbsp;Ernest Kenu,&nbsp;George Obeng Adjei,&nbsp;Ellis Owusu-Dabo,&nbsp;John Amuasi,&nbsp;Franklin Asiedu-Bekoe,&nbsp;Dennis Laryea,&nbsp;Francis Kasolo,&nbsp;Sally-Ann Ohene,&nbsp;Angela M.C. Rose,&nbsp;Kwaku Poku Asante","doi":"10.1016/j.vaccine.2026.128310","DOIUrl":"10.1016/j.vaccine.2026.128310","url":null,"abstract":"<div><h3>Background</h3><div>The use of vaccines to urgently respond to the COVID-19 pandemic generated the need for monitoring vaccine effectiveness in the context of new viral variants and changing epidemiology. This study measured the COVID-19 vaccine effectiveness (VE) against laboratory-confirmed SARS-CoV-2 in hospitalised patients diagnosed with severe acute respiratory infections (SARI) in Ghana.</div></div><div><h3>Methods</h3><div>This was a test-negative, case-control study, among patients aged ≥15 years, attending 32 hospitals that participate in influenza surveillance system between June 2022 and March 2024. Naso-and oropharyngeal swabs were tested for SARS-CoV-2 by PCR. Medical and vaccination data were obtained. VE was estimated as one minus adjusted odds of vaccination among participants, expressed as a percentage, and the reference was either unvaccinated cases (absolute VE) or unvaccinated plus those vaccinated &gt;12 months prior to symptom onset (annual VE).</div></div><div><h3>Results</h3><div>Of 1974 SARI patients, 1796 (91%) were enrolled, including 929/1796 males (52%) and 867/1796 females (48%); 41% were above 60 years old. At least one chronic medical condition was reported in 167/1796 (9%) participants. A total of 118/1796 (7%) tested positive for SARS-CoV-2, of whom 29 (25%) have received at least one dose of vaccine (Sputnik V, Vaxzevria, JCovden, or Comirnaty). Of the 1678 (93%) who tested negative for SARS-CoV-2, 412 (25%) received at least one dose of vaccine. Among pregnant women (<em>n</em> = 50), 5 (10%) tested positive for SARS-CoV-2 Absolute and annual VE against COVID-19 SARI hospitalization were respectively 22% (95% CI, −107–70) and 19% (95% CI, −113%–50%) for last dose of vaccine received up to 179 days prior but waned after 6 months.</div></div><div><h3>Conclusion</h3><div>COVID-19 vaccines may have prevented COVID-19-associated SARI hospitalizations in the first 6 months over the study period in Ghana, and a pattern of protective effective was observed, consistent with report from other settings, although effect estimates were imprecise.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 128310"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146222678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of COVID-19 vaccines against laboratory-confirmed SARS-CoV-2 infection amongst health workers, Windhoek, Namibia","authors":"Kaveto Sikuvi,&nbsp;Natasha Nghitukwa,&nbsp;Ndiitodino Kakehongo,&nbsp;Ismael Katjitae,&nbsp;Carolina Matos,&nbsp;Philip Oedi,&nbsp;Sibongile Manga Netha,&nbsp;Emmanuel Nepolo,&nbsp;Christian Winter","doi":"10.1016/j.vaccine.2025.126977","DOIUrl":"10.1016/j.vaccine.2025.126977","url":null,"abstract":"<div><h3>Introduction</h3><div>As of 24 October 2021, 128,868 laboratory-confirmed COVID-19 cases and 3550 deaths were reported from Namibia. The national COVID-19 vaccination campaign that started in March 2021 included health workers (HWs) as a priority group. The vaccines most administered were Sinopharm, AstraZeneca, Pfizer-BioNtech, and Janssen. We aimed to measure the effectiveness of COVID-19 vaccines (VE) amongst HWs against laboratory-confirmed SARS-CoV-2 infection in Namibia.</div></div><div><h3>Methods</h3><div>We conducted a test negative design (TND) amongst HWs from the two main hospitals treating COVID-19 patients. HWs were defined as all hospital staff over 18 years in direct or indirect contact with patients, eligible for COVID-19 vaccination. We interviewed actively recruited HWs with standardized questionnaires in-person from 25/10/2021 to 25/4/2022. The participants had to state their vaccination status, which was verified through vaccination card, vaccine registry and/or District Health Information System 2. RT-PCR testing of respiratory specimens and serological testing (Wantai and Platelia-ELISA) were conducted. We measured VE by comparing the vaccination status between RT-PCR positive and negative HWs using a multivariable logistic regression model, which was adjusted for confounders. We calculated VE = (1-odds ratio of vaccination)*100 %.</div></div><div><h3>Results</h3><div>We included 1201 HWs of which 322 (26.8 %) participants were fully vaccinated with a primary series against COVID-19, 62 (5.2 %) were partially vaccinated and 735 (61.2 %) were not vaccinated. In total, 1119 (93 %) participants had antibodies against SARS-CoV-2 including 637 (90 %) of the unvaccinated participants. Fifty-eight (4.8 %) participants tested RT-PCR positive for SARS-CoV-2. The Omicron variant was detected in all 13 sequenced genomes (11 BA.1.18, 2 BA.1). The estimated overall VE for full vaccination was 61.8 % (95 %-confidence interval, 9.3–83.9 %).</div></div><div><h3>Conclusions</h3><div>The VE results suggest that COVID-19 vaccines used in Namibia provided good protection from infections with the Omicron variant even if many participants had a SARS-CoV-2 infection before the study. Therefore, COVID-19 vaccines should be administered to risk groups such as HWs independent from previous infections.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 126977"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143617613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COVID-19 testing acceptance among symptomatic individuals screened for a randomized clinical trial in The Gambia","authors":"Mary Grey-Johnson,&nbsp;Abdul Khalie Muhammad,&nbsp;Fatoumata Sillah,&nbsp;Chiquita Joquina Jones,&nbsp;Catherine Sarr,&nbsp;Hakeem Edun Babatunde,&nbsp;Bakary Dibba,&nbsp;Ebrahim Ndure,&nbsp;Lamin Bojang,&nbsp;Charles Roberts,&nbsp;Mustapha Bittaye,&nbsp;Nuredin Mohammed,&nbsp;Behzad Nadjm,&nbsp;Umberto D'Alessandro,&nbsp;Anna Roca,&nbsp;Effua Usuf","doi":"10.1016/j.vaccine.2025.127608","DOIUrl":"10.1016/j.vaccine.2025.127608","url":null,"abstract":"<div><h3>Background</h3><div>Testing is a critical component to control disease outbreaks. The screening process required to enrol study participants from individuals with suspected COVID-19 disease in a clinical trial, presented an opportunity to explore factors that influence the willingness to be tested for COVID-19.</div></div><div><h3>Methods</h3><div>We analyzed data from individuals with symptoms suggestive of mild-moderate COVID-19 in two different health facilities in Western Gambia. As part of pre-enrollment screening for recruitment into a COVID-19 drug trial, we recorded clinical, epidemiological, and demographic information. Individuals who consented had a nasopharyngeal and/or oropharyngeal sample collected for SARS-CoV-2 testing. We compared consenting and non-consenting individuals using univariate and multivariable logistic regression and calculated adjusted odds ratio. Over-time trends were visualised using a 30-day moving sum for participants who consented.</div></div><div><h3>Results</h3><div>Among the 1361 suspected COVID-19 individuals identified between January 2021 and August 2022, 33.4 % (458/1361) consented to be tested for SARS-CoV-2. In the multivariate analysis, history of smoking (aOR: 3.07, 95 %CI: 1.60–5.88 <em>p</em> &lt; 0.001), high educational level (aOR: 6.32, 95 %CI: 3.84–10.39 p &lt; 0.001), history of travel (aOR: 2.94, 95 %CI: 1.20–7.22, <em>p</em> = 0.019), and loss of smell (aOR: 4.00, 95 %CI: 2.24–7.17 <em>p</em> = 0.002,) were significantly associated with acceptance to COVID-19 testing. The 30-day moving sum showed a downward trend of testing acceptance over time.</div></div><div><h3>Conclusion</h3><div>Although testing acceptance was very low, individuals with recognised risk factors for COVID-19 were more likely to accept testing. Early and sustained information about these risk factors particularly targeting individuals in low-education cadres may enhance testing uptake during a pandemic.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 127608"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144862760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disclaimer Page","authors":"","doi":"10.1016/S0264-410X(26)00307-5","DOIUrl":"10.1016/S0264-410X(26)00307-5","url":null,"abstract":"","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 128499"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148020565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing the African region monitoring vaccine effectiveness (AFRO-MoVE) network for respiratory pathogens","authors":"C.E. Gurry,&nbsp;J.M. Mwenda,&nbsp;A. Nardone,&nbsp;S. Cohuet,&nbsp;A. Worwui,&nbsp;M. Valenciano,&nbsp;H.C. Lewis,&nbsp;C.S. Wiysonge,&nbsp;R. Katsande,&nbsp;R. Mukaro,&nbsp;F. Braka,&nbsp;A.S. Gueye,&nbsp;T. Balde,&nbsp;I. Bergeri,&nbsp;B. Impouma,&nbsp;the AFRO-MoVE Network","doi":"10.1016/j.vaccine.2024.126616","DOIUrl":"10.1016/j.vaccine.2024.126616","url":null,"abstract":"<div><div>Population-level vaccination with newly developed vaccines to respond to the COVID-19 pandemic created a need to monitor vaccine effectiveness (VE) in the context of emerging SARS-CoV-2 variants and changing epidemiology. WHO and partners launched the African Region Monitoring Vaccine Effectiveness (AFRO-MoVE) Network in March 2021 to assess the performance of COVID-19 vaccines in real-world conditions in Africa.</div><div>The Network aimed to facilitate and support comparable COVID-19 vaccine effectiveness studies in the African region, to provide a platform of scientific expertise and infrastructure, encourage the use of robust similar study designs to enable pooling to produce regional VE estimates and to build a sustainable network of hospitals, institutions, and experts to evaluate vaccines against pandemic and endemic respiratory pathogens.</div><div>In the two years since its inception, the network has coordinated VE studies in the region and provided technical guidance and generic protocols employing robust methodologies. It brought together over 200 experts, representing 22 African countries and 55 organisations, and strengthened capacities by hosting ten webinars and six technical workshops. Of the 55 partners organisations, 25 based in 13 countries collaborated on implementing VE studies in the region.</div><div>AFRO-MoVE supported study implementation in two phases, first targeting COVID-19 vaccination priority groups, then the general population. The network provides technical and financial support to nine studies, including three cohort studies in health workers and adults with comorbidities, and six test-negative design studies evaluating VE against symptomatic and severe disease. A data platform was established for pooled regional estimates.</div><div>The AFRO-MoVE Network can form a sustainable platform to provide data for evidence informed decisions and timely VE monitoring for existing and new vaccines against respiratory pathogens and other diseases in the African region. Further development and consolidation of the network’s activities can enable rapid response to future epidemics and pandemics.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 126616"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142916757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COVID-19 vaccination status and associated factors among patients presenting with COVID-19-like symptoms in Uganda","authors":"Sylvia Kusemererwa,&nbsp;Violet Ankunda,&nbsp;Terry A. Ongaria,&nbsp;Andrew Abaasa,&nbsp;Ayoub Kakande,&nbsp;Deogratius Ssemwanga,&nbsp;Geofrey Kimbugwe,&nbsp;Bernadette Nayiga,&nbsp;Henry K. Bosa,&nbsp;Alfred Driwale,&nbsp;Yonas T. Woldemariam,&nbsp;Annet Kisakye,&nbsp;James Humphreys,&nbsp;Archibald K. Worwui,&nbsp;Sandra Cohuet,&nbsp;Jason M. Mwenda,&nbsp;Alison M. Elliott,&nbsp;Pontiano Kaleebu,&nbsp;Eugene Ruzagira","doi":"10.1016/j.vaccine.2025.126984","DOIUrl":"10.1016/j.vaccine.2025.126984","url":null,"abstract":"<div><h3>Introduction</h3><div>The emergence of new SARS-CoV-2 variants threatens the effectiveness of global vaccination campaigns. This study examines the vaccination status and associated factors among patients presenting with COVID-19-like symptoms at 19 healthcare facilities in Uganda.</div></div><div><h3>Materials and methods</h3><div>A cross-sectional analysis was conducted using data collected at health facilities to evaluate the effectiveness of COVID-19 vaccines in Uganda from March 2023 to March 2024. Participants were individuals aged 12 years and older with COVID-19-like symptoms who underwent a SARS-CoV-2 qPCR test within 10 days of symptom onset. The study involved obtaining informed consent, collecting medical and vaccination histories (confirmed using vaccination cards and Ministry of Health COVID-19 database), performing physical examinations, administering a questionnaire, and taking oral/nasopharyngeal swabs for SARS-CoV-2 qPCR testing. Vaccination coverage was defined as receiving at least one vaccine dose. Logistic regression was used to identify factors associated with vaccination status.</div></div><div><h3>Results</h3><div>Among 1398 participants enrolled (55.4 % female), the median age was 30.0 years (IQR: 24.0–41.0). Vaccination coverage, was 66.6 %. Residing in Wakiso district compared to the Capital, Kampala was associated with a higher likelihood of vaccination (adjusted odds ratio [aOR] = 1.4, 95 % CI: 1.0–1.8, <em>p</em> = 0.021). Frontline and healthcare workers were more likely to be vaccinated (aOR = 5.0, 95 % CI: 3.6–7.3, <em>p</em> &lt; 0.001), as were individuals with a previous COVID-19 diagnosis (aOR = 2.4, 95 % CI: 1.6–3.9, p &lt; 0.001).</div></div><div><h3>Conclusions</h3><div>Our results underscore the need for targeted public health messaging and support to promote vaccination, especially among non-healthcare workers. Addressing these gaps is crucial for maintaining high vaccination coverage and mitigating the impact of new SARS-CoV-2 variants on the population.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 126984"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143588816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors associated with laboratory-confirmed SARS-Cov-2 infection among patients with severe respiratory illness (SRI): Findings from the COVID-19 vaccine effectiveness evaluation in Kenya and Mali, 2022–2023","authors":"Raphael O. Anyango,&nbsp;Bryan O. Nyawanda,&nbsp;Brian O. Onyando,&nbsp;Fadima C. Haidara,&nbsp;Collins Okello,&nbsp;Ian K. Orege,&nbsp;Sidney Ogolla,&nbsp;Billy Ogwel,&nbsp;Alex O. Awuor,&nbsp;Samuel Kadivane,&nbsp;Philip Ngere,&nbsp;Carolyne Nasimiyu,&nbsp;Eric Osoro,&nbsp;M. Kariuki Njenga,&nbsp;Victor Akelo,&nbsp;Amos Otedo,&nbsp;Shirley Lidechi,&nbsp;John B. Ochieng,&nbsp;Nancy A. Otieno,&nbsp;Erick M.O. Muok,&nbsp;Richard Omore","doi":"10.1016/j.vaccine.2025.127234","DOIUrl":"10.1016/j.vaccine.2025.127234","url":null,"abstract":"<div><h3>Background</h3><div>Understanding the epidemiology of SARS-CoV-2 infection in settings with limited data, especially given the dynamic nature of the virus and the reported epidemiological heterogeneity across countries, is important. We used data from the COVID-19 Vaccine effectiveness evaluation to determine factors associated with SARS-COV-2 infection among patients (≥ 12 years) with severe respiratory illness (SRI) in Kenya and Mali.</div></div><div><h3>Methods</h3><div>SRI was defined as acute onset (≤ 14 days) of at least two of the following: cough, fever, chills, rigors, myalgia, headache, sore throat, fatigue, congestion or runny nose, loss of taste or smell, or pneumonia diagnosis. We collected demographic and clinical characteristics of the patients, and nasopharyngeal and oropharyngeal specimens for SARS-CoV-2 testing using RT-PCR. We used a mixed effect logistic regression to determine factors associated with SARS-CoV-2 infection adjusting for age and sex while controlling for clustering by site and month of illness onset.</div></div><div><h3>Results</h3><div>Between July 2022 and October 2023, a total of 9941 patients with SRI were enrolled, of whom, 588 (5.9 %) tested positive for SARS-CoV-2. Compared to patients aged 12–24 years, those who were aged &gt;64 years were more likely to have SARS-CoV-2 infection (adjusted Odds Ratio [aOR] = 1.60; 95 % Confidence Interval [95 % CI] 1.07–2.40). Additionally, SRI patients presenting with cough (aOR = 1.37; 95 % Confidence Interval [95 % CI] 1.05–1.80), sore throat (aOR = 1.56; 95 % CI 1.23–1.99), runny nose (aOR = 1.51; 95 % CI 1.18–1.94), and ear pain discharge (aOR = 2.58; 95 % CI 1.43–4.66) were more likely to have SARS-CoV-2 infection compared to those who did not. SRI patients who had HIV were also more likely to have SAR-CoV-2 infection compared to those who did not (aOR =1.32; 95 % CI 1.04–1.67).</div></div><div><h3>Conclusion</h3><div>Older adults and HIV patients were at increased-risk of SARS-CoV-2 infection consistent with WHO guidelines highlighting the need for targeted prevention and management strategies focused on them.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 127234"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144051276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics and seroprevalence of anti-SARS-CoV-2 antibodies in vaccinated and unvaccinated health workers in Bamako, Mali, November 2021–February 2023","authors":"Saidou Balam,&nbsp;Fousseyni Kane,&nbsp;Bourama Traore,&nbsp;Drissa Konate,&nbsp;Fatimata A. Diallo,&nbsp;Housseini Dolo,&nbsp;Anou Moise Somboro,&nbsp;Ousmane Kodio,&nbsp;Antieme Combo Georges Togo,&nbsp;Bassirou Diarra,&nbsp;Nathan C. Incandela,&nbsp;Fatoumata Diallo,&nbsp;Abdouramane Traore,&nbsp;Salimata Kante,&nbsp;Merepen dite Agnes Guindo,&nbsp;Bourema Kouriba,&nbsp;Yaya Ibrahim Coulibaly,&nbsp;Ousmane Faye,&nbsp;Seydou Doumbia,&nbsp;Mahamadou Diakite","doi":"10.1016/j.vaccine.2025.127680","DOIUrl":"10.1016/j.vaccine.2025.127680","url":null,"abstract":"<div><h3>Background</h3><div>This prospective study aimed to evaluate the dynamics and seroprevalence of anti-SARS-CoV-2 antibodies in a cohort of vaccinated and unvaccinated health workers (HWs) in Bamako, Mali. The study also measured antibody responses as a function of SARS-CoV-2 infections, socio-demography, vaccination status and associated comorbidities.</div></div><div><h3>Method</h3><div>685 vaccinated and 413 unvaccinated HWs (total = 1098) were monitored over a 15-month periods with follow-up visits every 3 months for the first 6 months and a final visit after 15 months. Anti-spike and anti-nucleoprotein antibodies were assessed using ELISA. Non-parametric tests and logistic regression analyses were performed to compare antibody levels and to investigate associated factors.</div></div><div><h3>Results</h3><div>Overall, anti-SARS-CoV-2 antibodies tended to increase over the first 3 months in both vaccinated and unvaccinated groups. Spike (&gt;98 %) and nucleoprotein (&gt;91 %) antibodies remained high and relatively stable after 3 months and correlated inversely with the rate attack of symptomatic and asymptomatic COVID-19. Males demonstrated lower antibody responses, particularly for nucleoprotein (<em>p</em> &lt; 0.05) compared to females. HWs with comorbidities demonstrated higher antibody responses. Participants with active SARS-CoV-2 infections exhibited decreased antibody levels. Vaccinated participants exhibited a trend toward higher spike antibodies. Virus-inactivated type vaccination increased nucleoprotein antibodies. Furthermore, there was no increase of antibody levels after receiving, two or more vaccine doses, independently of whether the same or a different type of used vaccines. Nucleoprotein antibodies varied significantly at inclusion among participants across blood groups.</div></div><div><h3>Conclusion</h3><div>This study identified a progressive increase in anti-spike and anti-nucleoprotein antibodies in both vaccinated and unvaccinated HWs, correlating with reduced COVID-19 infection rates. These findings highlight the significance of both natural and vaccine-induced immunity and the need to assess antibody levels and long-term protection beyond the 15-month study period.</div></div>","PeriodicalId":23491,"journal":{"name":"Vaccine","volume":"77 ","pages":"Article 127680"},"PeriodicalIF":4.5,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144984675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}