The main coronavirus disease 2019 (COVID-19) vaccine formulations used today are mainly based on the wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein as an antigen. However, new virus variants capable of escaping neutralization activity of serum antibodies elicited in vaccinated individuals have emerged. The Omicron (B.1.1.529) variant caused epidemics in regions of the world in which most of the population has been vaccinated. In this study, we aimed to understand what determines individual's susceptibility to Omicron in a scenario of extensive vaccination. For that purpose, we collected nasopharynx swab (n = 286) and blood samples (n = 239) from flu-like symptomatic patients, as well as their vaccination history against COVID-19. We computed the data regarding vaccine history, COVID-19 diagnosis, COVID-19 serology, and viral genome sequencing to evaluate their impact on the number of infections. As main results, we showed that vaccination in general did not reduce the number of individuals infected by Omicron, even with an increased immune response found among vaccinated, noninfected individuals. Nonetheless, we found that individuals who received the third vaccine dose showed significantly reduced susceptibility to Omicron infections. A relevant evidence that support this finding was the higher virus neutralization capacity of serum samples of most patients who received the third vaccine dose. In summary, this study shows that boosting immune responses after a third vaccine dose reduces susceptibility to COVID-19 caused by the Omicron variant. Results presented in this study are useful for future formulations of COVID-19 vaccination policies.
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http://dx.doi.org/10.1002/jmv.28481 | DOI Listing |
Lancet Microbe
January 2025
Jenner Institute, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, UK.
Background: R21 is a novel malaria vaccine, composed of a fusion protein of the malaria circumsporozoite protein and hepatitis B surface antigen. Following favourable safety and immunogenicity in a phase 1 study, we aimed to assess the efficacy of R21 administered with Matrix-M (R21/MM) against clinical malaria in adults from the UK who were malaria naive in a controlled human malaria infection study.
Methods: In this open-label, partially blinded, phase 1-2A controlled human malaria infection study undertaken in Oxford, Southampton, and London, UK, we tested five novel vaccination regimens of R21/MM.
Hum Vaccin Immunother
December 2025
Clinical Development, Takeda Pharmaceuticals International AG, Zurich, Switzerland.
As infants suffer significant morbidity and mortality due to norovirus-related acute gastroenteritis (AGE), we assessed four formulations of the bivalent virus-like particle (VLP) vaccine candidate (HIL-214) in Panamanian and Colombian infants. 360 infants aged 6 weeks to 5 months were randomly allocated to 8 groups to receive three doses of HIL-214 or two doses of HIL-214 and one dose of placebo (Days 1, 56 and 112), where HIL-214 doses contained 15/15, 15/50, 50/50 or 50/150 μg of GI.1/GII.
View Article and Find Full Text PDFImmunol Lett
January 2025
Miami Transplant Institute, Jackson Health System, Miami, FL, USA; Department of Medicine, Division of Nephrology, University of Miami Miller School of Medicine Miami, FL, USA. Electronic address:
Introduction: In Solid Organ Transplant (SOT) recipients, due to immunosuppression, the immunogenicity after COVID-19 vaccination is suboptimal and its durability is unknown.
Methods: We conducted a post-hoc analysis of a patient-blinded, single center, randomized controlled trial comparing BNT162b2 vs JNJ-78436735 as the third dose after two doses of BNT162b2 in adult SOT recipients with active graft to compare long-term immunogenicity.
Results: Forty-one recipients were analyzed.
Public Health
January 2025
Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Third Hospital of Shanxi Medical University, Tongji Shanxi Hospital, Taiyuan, 030032, China; Department of Allergy, Immunology & Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan; Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan; Institute of Medicine/Department of Nursing, Chung Shan Medical University, Taichung, Taiwan. Electronic address:
Objectives: Limited data are available to assess breakthrough SARS-CoV-2 infections, medical utilization, and mortality in patients with tuberculosis (TB). The aim of this study was to examine the risk of COVID-19 and severe outcomes in patients with TB between January 2020 and March 2022.
Study Design: US electronic medical records were used to identify TB and non-TB patients who completed the primary series of vaccination and had no prior COVID-19.
Hum Vaccin Immunother
December 2025
Academy of Preventive Medicine, Shandong University, Jinan, China.
Acute hepatitis E infection could induce severe outcomes among chronic hepatitis B (CHB) patients. Between 2016 and 2017, an open-label study was conducted to evaluate the immunogenicity and safety of hepatitis E vaccine (HepE) in CHB patients, using healthy adults as parallel controls in China. Eligible participants who were aged ≥30 y were enrolled in the study.
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