Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (1,312)

Search Parameters:
Keywords = vaccine doses received

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
10 pages, 1240 KiB  
Perspective
Designing for Equity: An Evaluation Framework to Assess Zero-Dose Reduction Efforts in Southern Madagascar
by Guillaume Demare, Elgiraud Ramarosaiky, Zavaniarivo Rampanjato, Nadine Muller, Beate Kampmann and Hanna-Tina Fischer
Vaccines 2025, 13(8), 834; https://doi.org/10.3390/vaccines13080834 (registering DOI) - 5 Aug 2025
Abstract
Despite growing global momentum to reduce the number of children who never received a dose of any vaccine, i.e., zero-dose (ZD) children, persistent geographic and social inequities continue to undermine progress toward universal immunization coverage. In Madagascar, where routine vaccination coverage remains below [...] Read more.
Despite growing global momentum to reduce the number of children who never received a dose of any vaccine, i.e., zero-dose (ZD) children, persistent geographic and social inequities continue to undermine progress toward universal immunization coverage. In Madagascar, where routine vaccination coverage remains below 50% in most regions, the non-governmental organization Doctors for Madagascar and public sector partners are implementing the SOAMEVA program: a targeted community-based initiative to identify and reach ZD children in sixteen underserved districts in the country’s south. This paper outlines the equity-sensitive evaluation design developed to assess the implementation and impact of SOAMEVA. It presents a forward-looking evaluation framework that integrates both quantitative program monitoring and qualitative community insights. By focusing at the fokontany level—the smallest administrative unit in Madagascar—the evaluation captures small-scale variation in ZD prevalence and program reach, allowing for a detailed analysis of disparities often masked in aggregated data. Importantly, the evaluation includes structured feedback loops with community health workers and caregivers, surfacing local knowledge on barriers to immunization access and program adoption. It also tracks real-time adaptations to implementation strategy across diverse contexts, offering insight into how routine immunization programs can be made more responsive, sustainable, and equitable. We propose eight design principles for conducting equity-sensitive evaluation of immunization programs in similar fragile settings. Full article
(This article belongs to the Special Issue Inequality in Immunization 2025)
Show Figures

Figure 1

17 pages, 2767 KiB  
Article
Frequency, Timing, Burden and Recurrence of Adverse Events Following Immunization After HPV Vaccine Based on a Cohort Event Monitoring Study in the Netherlands
by Monika Raethke, Jeroen Gorter, Rachel Kalf, Leontine van Balveren, Rana Jajou and Florence van Hunsel
Vaccines 2025, 13(8), 812; https://doi.org/10.3390/vaccines13080812 (registering DOI) - 30 Jul 2025
Viewed by 361
Abstract
Background/Objectives: The aim of this study was to systematically assess Adverse Events Following Immunization (AEFI) among children following administration of the human papillomavirus (HPV) vaccine (Cervarix®) included in the Dutch National Immunization Program (NIP) and to characterize the pattern and recurrence [...] Read more.
Background/Objectives: The aim of this study was to systematically assess Adverse Events Following Immunization (AEFI) among children following administration of the human papillomavirus (HPV) vaccine (Cervarix®) included in the Dutch National Immunization Program (NIP) and to characterize the pattern and recurrence risk of AEFI after HPV revaccination. Methods: A longitudinal cohort event monitoring study, using patient-reported outcomes was used among recipients of the HPV vaccine at 10 years of age. Data were available for 3063 children following the first HPV vaccination and for 2209 children following the second HPV vaccination. Results: The most commonly reported AEFI following HPV vaccination were injection site reactions—reported by 46.5% of participants after the first dose and 31.9% after the second dose—followed by headache (8.2% and 3.9%, respectively) and joint pain (4.5% and 3.7%, respectively). Participants who received both HPV vaccine doses reported more AEFI after the first dose than after the second. Among girls, 61.2% reported at least one AEFI following the first dose, compared to 44.2% after the second dose. For boys, these percentages were 55.3% and 38.5%, respectively. This difference was statistically significant (p = 0.002). For some AEFI, such as injection site reactions, there appears to be a potential increased risk of recurrence following the second dose. Conclusions: This prospective longitudinal cohort event monitoring study showed that AEFI were more frequent after the first HPV dose and more frequent for girls compared to boys. An increased risk of recurrence was seen for AEFI, such as injection site reactions and headache. Furthermore, this study provides insight into the course of AEFI and the extent to which children were affected by these symptoms based on real-world data. Full article
(This article belongs to the Section Human Papillomavirus Vaccines)
Show Figures

Figure 1

13 pages, 291 KiB  
Article
Assessment of SARS-CoV-2 Infection, Vaccination, and Immunity Status Among a Population of Dentists/Academic Professors in a Clinical Setting: One-Year Findings
by Patricia Manarte-Monteiro, Gabriella Marques, Dina Alves, Mary Duro, Joana Domingues, Sandra Gavinha, Lígia Pereira da Silva and Liliana Teixeira
COVID 2025, 5(8), 120; https://doi.org/10.3390/covid5080120 - 28 Jul 2025
Viewed by 170
Abstract
Background: This study aimed to assess the prevalence of SARS-CoV-2 infection, vaccination, and immune status among a population, both Dentists and University Professors, within a clinical setting at one and at 12 months after COVID-19 vaccination. Methods: A cross-sectional study involving 47 professionals [...] Read more.
Background: This study aimed to assess the prevalence of SARS-CoV-2 infection, vaccination, and immune status among a population, both Dentists and University Professors, within a clinical setting at one and at 12 months after COVID-19 vaccination. Methods: A cross-sectional study involving 47 professionals (aged 27–52) was conducted in the University Fernando Pessoa. Participants completed an online survey on SARS-CoV-2 infection status and vaccination, received and provided plasma samples for serological analysis. The protocol was approved by the UFP-Ethics Committee. Anti-S1-RBD SARS-CoV-2 IgM and IgG antibody titration values (AU/mL) were measured, by enzyme-linked-immunosorbent assay (ELISA), with reactive immunoglobulins (Ig) seropositivity for values ≥1 AU/mL. Results: SARS-CoV-2 infection rate increased from 8.5% in July 2021 to 48.9% in June 2022, with 8.5% experiencing reinfection. Vaccination rate was 91.5% by July 2021 and increased slightly to 93.6% by June 2022; 72.3% of the sample received a third dose. IgG seropositivity increased from 91.5% to 95.7% in June 2022. After one-year, significant associations were found between IgG seropositivity and both participant’s age (p = 0.009; <50 years) and vaccine doses (p = 0.003; 1–3 doses) received. Conclusions: SARS-CoV-2 infection rate, vaccination, and IgG seropositivity rates were high and increased over one year. The age and vaccination status were associated with the immunity status at 12th month follow-up. Findings highlight variability in IgG seroprevalence due to multiple influencing factors, which justifies future studies. Full article
(This article belongs to the Section COVID Clinical Manifestations and Management)
6 pages, 1774 KiB  
Perspective
Case Series: Reactivation of Herpetic Keratitis After COVID-19 mRNA Vaccination During Herpetic Prophylaxis
by Michael Tsatsos, Efthymia Prousali, Athanasios Karamitsos and Nikolaos Ziakas
Vision 2025, 9(3), 63; https://doi.org/10.3390/vision9030063 - 28 Jul 2025
Viewed by 293
Abstract
This report presents two cases of herpes simplex keratitis recurrence after COVID-19 mRNA vaccination in patients on herpetic prophylaxis due to recurrent herpetic keratitis. A 58-year-old man with a history of a previous penetrating keratoplasty presented with blurred vision and evidence of corneal [...] Read more.
This report presents two cases of herpes simplex keratitis recurrence after COVID-19 mRNA vaccination in patients on herpetic prophylaxis due to recurrent herpetic keratitis. A 58-year-old man with a history of a previous penetrating keratoplasty presented with blurred vision and evidence of corneal endothelitis 48 h after the first dose of the m-RNA vaccination, and a 24-year-old male student came with a dendritic ulcer 72 h post first vaccination dose. The original prophylactic treatment of 400 mg of acyclovir twice daily was increased to five times per day for a week for both patients. The grafted patient additionally received an increase in Dexamethasone 0.1% from twice daily to four times a day. Improvement was noted within two days and documented at the weekly review, during which both patients returned to their prophylactic antiviral regime without further recurrence. At the time of their second dose of vaccination, both patients followed the same regime with an increase in treatment as per the first dose of vaccination without recurrence. Our findings suggest that patients with recurrent herpetic disease receiving prophylactic treatment need close monitoring when experiencing even subtle symptoms of recurrence and may benefit from an increase in their dose to therapeutic levels during the first days after the COVID-19 mRNA vaccination. Full article
Show Figures

Figure 1

12 pages, 634 KiB  
Article
Impaired Long-Term Quantitative Cellular Response to SARS-CoV-2 Vaccine in Thiopurine-Treated IBD Patients
by Luis Mayorga Ayala, Claudia Herrera-deGuise, Juliana Esperalba, Xavier Martinez-Gomez, Elena Céspedes Martinez, Xavier Serra Ruiz, Virginia Robles, Ernesto Lastiri, Zahira Perez, Elena Oller, Candela Fernandez-Naval, Mónica Martinez-Gallo, Francesc Casellas and Natalia Borruel
Cells 2025, 14(15), 1156; https://doi.org/10.3390/cells14151156 - 26 Jul 2025
Viewed by 329
Abstract
Background: Studies investigating the long-term cellular immune response to SARS-CoV-2 mRNA vaccines in patients with inflammatory bowel disease (IBD) remain limited, particularly among those receiving immunosuppressive therapy. Methods: We prospectively evaluated humoral and cellular immune responses at short-term (4–6 weeks) and [...] Read more.
Background: Studies investigating the long-term cellular immune response to SARS-CoV-2 mRNA vaccines in patients with inflammatory bowel disease (IBD) remain limited, particularly among those receiving immunosuppressive therapy. Methods: We prospectively evaluated humoral and cellular immune responses at short-term (4–6 weeks) and long-term (6–12 months) time points following SARS-CoV-2 mRNA vaccination in patients with IBD receiving anti-TNF agents, thiopurines, or combination therapy. We defined the short-term response as the measurement taken 4–6 weeks after the second vaccine dose and the long-term response as the measurement taken between 6 and 12 months after the first determination. A cohort of healthy controls was included for short-term comparative analysis. Results: At long-term follow-up, quantitative humoral responses were reduced in patients receiving anti-TNF monotherapy. In contrast, a reduced quantitative cellular response was found in the thiopurine (median 0.7 UI/mL, p < 0.05) and anti-TNF combo groups (median 0.4 UI/mL, p < 0.01) compared to anti-TNF monotherapy (median 2.2 UI/mL). Conclusions: There was a robust long-term humoral and cellular response to vaccination, but a diminished quantitative cellular response in patients treated with thiopurines or combo therapy compared to anti-TNF monotherapy. Full article
(This article belongs to the Section Cellular Immunology)
Show Figures

Figure 1

13 pages, 518 KiB  
Article
COVID-19 Vaccination Still Makes Sense: Insights on Pneumonia Risk and Hospitalization from a Large-Scale Study at an Academic Tertiary Center in Italy
by Elena Azzolini, Brenda Lupo Pasinetti, Antonio Voza, Antonio Desai, Michele Bartoletti, Stefano Aliberti and Massimiliano Greco
Microorganisms 2025, 13(8), 1744; https://doi.org/10.3390/microorganisms13081744 - 25 Jul 2025
Viewed by 212
Abstract
COVID-19 vaccines have revolutionized prevention and clinical management by reducing disease severity and mortality. However, their long-term impact on hospitalization is unclear. This retrospective study assessed whether vaccination status, timing, and number of vaccine doses influence the risk of hospitalization and COVID-19 pneumonia [...] Read more.
COVID-19 vaccines have revolutionized prevention and clinical management by reducing disease severity and mortality. However, their long-term impact on hospitalization is unclear. This retrospective study assessed whether vaccination status, timing, and number of vaccine doses influence the risk of hospitalization and COVID-19 pneumonia in a large cohort in Italy, several years after initial vaccine rollout. From 1 October 2023, to 2 February 2024, at Humanitas Research Hospital (Milan) and two affiliates, we recorded age, sex, comorbidities, vaccination status (number of doses and time since last dose), admission type (urgent vs. elective), and pneumonia diagnosis. Baseline health was quantified by the Charlson Comorbidity Index. Among 16,034 admissions (14,874 patients), vaccination data were available for 5743 cases: 40.8% were in the emergency setting and 59.2% were elective. Patients presented with pneumonia in 6.8% of cases. Laboratory results confirmed COVID-19 pneumonia occurred in 43.7% of pneumonia cases, with a 16.9% mortality. Patients with no vaccine dose had a higher proportion of COVID-19 pneumonia, while COVID-19 pneumonia rates were lower in individuals who had received more vaccine doses. There were no significant differences in COVID-19 pneumonia risk by timing of last vaccination. Moreover, hospitalized unvaccinated patients had overall more frequent emergency admissions (57.3%), while patients with three or more doses had about a ~40% emergency admission rate. COVID-19 positivity during hospitalization was highest in unvaccinated patients (90.7%) and declined with vaccination status. Vaccinated patients, especially those with multiple doses, had significantly lower COVID-19 pneumonia rates and emergency admissions. These findings suggest a possible protective effect of vaccination in modifying the clinical presentation and severity of illness among those who are hospitalized and support continued vaccination efforts for high-risk groups to reduce severe adverse outcomes. Full article
(This article belongs to the Special Issue SARS-CoV-2: Infection, Transmission, and Prevention)
Show Figures

Figure 1

15 pages, 1304 KiB  
Article
Correlates of SARS-CoV-2 Breakthrough Infections in Kidney Transplant Recipients Following a Third SARS-CoV-2 mRNA Vaccine Dose
by Miriam Viktov Thygesen, Charlotte Strandhave, Jeanette Mølgaard Kiib, Randi Berg, Malene Söth Andersen, Emma Berggren Dall, Bodil Gade Hornstrup, Hans Christian Østergaard, Frank Holden Mose, Jon Waarst Gregersen, Søren Jensen-Fangel, Jesper Nørgaard Bech, Henrik Birn, Marianne Kragh Thomsen and Rasmus Offersen
Vaccines 2025, 13(8), 777; https://doi.org/10.3390/vaccines13080777 - 22 Jul 2025
Viewed by 260
Abstract
Background: Kidney transplant recipients (KTRs) exhibit a significantly diminished immune response to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) vaccines compared with the general population, primarily due to ongoing immunosuppressive therapy. This study evaluated the immunogenicity of a third SARS-CoV-2 mRNA vaccine dose in [...] Read more.
Background: Kidney transplant recipients (KTRs) exhibit a significantly diminished immune response to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) vaccines compared with the general population, primarily due to ongoing immunosuppressive therapy. This study evaluated the immunogenicity of a third SARS-CoV-2 mRNA vaccine dose in KTRs and assessed the association between antibody response and protection against SARS-CoV-2 breakthrough infection. Additionally, the clinical and immunological correlates of post-vaccination SARS-CoV-2 infection were examined. Methods: A prospective cohort of 135 KTRs received a third vaccine dose approximately six months following the second dose. Plasma samples were collected at baseline (pre-vaccination), six months after the second dose, and six weeks following the third dose. Humoral responses were assessed using SARS-CoV-2-specific Immunoglobulin G (IgG) titers and virus neutralization assays against wild-type (WT) and viral strains, including multiple Omicron sub-lineages. Results: After the third vaccine dose, 74% of the KTRs had detectable SARS-CoV-2-specific IgG antibodies, compared with 48% following the second dose. The mean IgG titers increased approximately ten-fold post-booster. Despite this increase, neutralizing activity against the Omicron variants remained significantly lower than that against the WT strain. KTRs who subsequently experienced a SARS-CoV-2 breakthrough infection demonstrated reduced neutralizing antibody activity across all variants tested. Additionally, individuals receiving triple immunosuppressive therapy had a significantly higher risk of SARS-CoV-2 breakthrough infection compared with those on dual or monotherapy. A multivariate machine learning analysis identified age and neutralizing activity against WT, Delta, and Omicron BA.2 as the most robust correlates of SARS-CoV-2 breakthrough infection. Conclusions: A third SARS-CoV-2 mRNA vaccine dose significantly improves SARS-CoV-2-specific IgG levels in KTRs; however, the neutralizing response against Omicron variants remains suboptimal. Diminished neutralizing capacity and intensified immunosuppression are key determinants of SARS-CoV-2 breakthrough infection in this immunocompromised population. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

11 pages, 1036 KiB  
Article
The Re-Emergence of Pediatric Pertussis: Insights from a Regional Romanian Hospital
by Ioana Rosca, Alina Turenschi, Alexandru Dinulescu and Victoria Lichii
Antibiotics 2025, 14(7), 730; https://doi.org/10.3390/antibiotics14070730 - 21 Jul 2025
Viewed by 349
Abstract
Introduction: Pertussis, a vaccine-preventable disease caused by Bordetella pertussis, is resurging globally due to declining immunization rates. This study explores the clinical and epidemiological features of pediatric pertussis cases in a regional Romanian hospital amid growing vaccine hesitancy. Methods: We conducted a retrospective [...] Read more.
Introduction: Pertussis, a vaccine-preventable disease caused by Bordetella pertussis, is resurging globally due to declining immunization rates. This study explores the clinical and epidemiological features of pediatric pertussis cases in a regional Romanian hospital amid growing vaccine hesitancy. Methods: We conducted a retrospective cohort study on 99 children diagnosed with pertussis and admitted to Ploiești Pediatric Hospital between January 2024 and January 2025. Demographic, clinical, laboratory, and radiological data were analyzed using SPSS 25.0. Results: The median age was 11 months (IQR 4–25), with 12.1% under two months, and ineligible for the first DTaP dose. Notably, 72.7% of children were unvaccinated; 59.4% had missed scheduled doses. None of the mothers received the DTaP vaccination during pregnancy. Most cases (55.6%) had bilaterally accentuated interstitial patterns on chest X-ray, significantly associated with vaccination status (p = 0.019). The leukocyte count was higher in children with alveolar infiltrates (p = 0.028), and as the number of vaccine doses increased, the leukocyte count tended to slightly decrease (p = 0.022, R = −0.229). PCR confirmation was obtained after a mean of 2.2 days, with 12.1% of cases confirmed post-discharge. Azithromycin was used in 74.7% of cases, with good tolerability. Conclusions: Low pediatric and maternal vaccine uptake was a major contributor to pertussis resurgence in this cohort. Radiological severity correlated with vaccination status, suggesting that vaccination may confer protection not only against infection but also against severe pulmonary involvement. These findings support urgent public health efforts to restore vaccine confidence and coverage, particularly among vulnerable infant populations and expectant mothers. Full article
Show Figures

Figure 1

19 pages, 318 KiB  
Article
Exploring Ukrainian Refugee Women’s Beliefs and Concerns About Healthcare Systems, with a Focus on HPV Immunization Practices: A Mixed-Methods Study on Forcibly Displaced Populations in Romania
by Teodora Achimaș-Cadariu, Andrei Pașca, Delia Nicoară and Dan Lucian Dumitrașcu
Healthcare 2025, 13(14), 1744; https://doi.org/10.3390/healthcare13141744 - 18 Jul 2025
Viewed by 393
Abstract
Objectives: Scarce data are available regarding preventive medicine in forcibly displaced populations especially regarding non-communicable diseases like neoplasia, while even more limited data are available on Ukrainian refugees in Romania. To address this research gap, the present analysis was performed to investigate [...] Read more.
Objectives: Scarce data are available regarding preventive medicine in forcibly displaced populations especially regarding non-communicable diseases like neoplasia, while even more limited data are available on Ukrainian refugees in Romania. To address this research gap, the present analysis was performed to investigate Ukrainian refugee women’s beliefs, attitudes, and opinions towards the Romanian and Ukrainian healthcare system in a comparison model while focusing on the HPV immunization rates and factors influencing the uptake for themselves and their children. Methods: Participants were recruited using the snowball sampling method through their General Practitioner (GP) and a health mediator. Results: In total, 105 women completed the online or physical survey. The mean age was 50 years. In total, 40% of women had not been to a gynecological check-up in 3 or more years, and more than 56% had never been screened. Only four were vaccinated against HPV, and none remembered which type of vaccine was dispensed or how many doses were utilized. The primary hindrances to accessing health services or immunization programs were language barriers, financial burdens, and a lack of information. Respondents’ general distrust of health systems and healthcare workforces were recurrent themes. Relationship status, living arrangements, and previous engagement in screening practices influenced immunization rates. Perceiving the healthcare officials as proactive concerning optional vaccination programs such as HPV immunization and actively receiving recommendations drove respondents to pursue vaccination. Conclusions: This analysis offers a foundational insight into the specific needs of refugee women. It can guide the development of effective public health interventions to improve health outcomes and vaccination rates among Ukrainian refugees in Romania. Tailored preventive campaigns with adequate native language information and prompts from medical experts in designated centers should be deployed to ensure inclusive tactics for vulnerable populations. Full article
14 pages, 2675 KiB  
Article
Development of a Clostridium Perfringens Challenge Model in Broiler Chickens to Evaluate the Effects of Feed Additives
by Anna Kollár, Kinga Selymes, Gergely Tóth, Sándor Szekeres, Péter Ferenc Dobra, Krisztina Bárdos, László Ózsvári, Zsófia Bata, Viviána Molnár-Nagy and Miklós Tenk
Pathogens 2025, 14(7), 707; https://doi.org/10.3390/pathogens14070707 - 17 Jul 2025
Viewed by 386
Abstract
Necrotic enteritis, caused by Clostridium perfringens (C. perfringens) is a disease present worldwide and causes major economic losses. The re-emergence of the disease, in recent years, is mainly due to the ban of the usage of antibiotics as growth promoters in [...] Read more.
Necrotic enteritis, caused by Clostridium perfringens (C. perfringens) is a disease present worldwide and causes major economic losses. The re-emergence of the disease, in recent years, is mainly due to the ban of the usage of antibiotics as growth promoters in the EU. The aim of this study was to establish a reliable, robust challenge model. Ross hybrid broilers were divided into randomized groups: a positive and a negative control group, a group receiving antibiotic treatment and three groups fed with assorted feed supplements, all receiving the same basal diet. The birds in the treatment groups were vaccinated twice using a 10-times dose of an Infectious Bursitis live vaccine and the animals were challenged four times with a NetB toxin producing C. perfringens strain. The presence of clinical signs and body weight gain were monitored. At the end of the study necropsy was performed and the gut lesions were scored. During the experiment, clinical signs were absent in the negative control group and in the antibiotic treated group. The other animals displayed diarrhea and feather loss. These symptoms were the most pronounced in the positive control group. The gut lesion scores showed significant differences between the negative and positive control groups, with the former scoring the lowest. Based on these results, the challenge model establishment was successful and in this setup the assessment of the potency of feed additives is also possible. Full article
Show Figures

Figure 1

11 pages, 1020 KiB  
Communication
XBB.1.5 COVID-19 mRNA Vaccines Induce Inadequate Mucosal Immunity in Patients with Inflammatory Bowel Disease
by Simon Woelfel, Joel Dütschler, Daniel Junker, Marius König, Georg Leinenkugel, Claudia Krieger, Samuel Truniger, Annett Franke, Seraina Koller, Katline Metzger-Peter, Nicola Frei, STAR SIGN Study Investigators, Werner C. Albrich, Matthias Friedrich, Jan Hendrik Niess, Nicole Schneiderhan-Marra, Alex Dulovic, Wolfgang Korte, Justus J. Bürgi and Stephan Brand
Vaccines 2025, 13(7), 759; https://doi.org/10.3390/vaccines13070759 - 16 Jul 2025
Viewed by 514
Abstract
Background: Mucosal immunity plays a pivotal role in preventing infections with SARS-CoV-2. While COVID-19 mRNA vaccines induce robust systemic immune responses in patients with inflammatory bowel disease (IBD), little is known about their efficacy in the mucosal immune compartment. In this sub-investigation of [...] Read more.
Background: Mucosal immunity plays a pivotal role in preventing infections with SARS-CoV-2. While COVID-19 mRNA vaccines induce robust systemic immune responses in patients with inflammatory bowel disease (IBD), little is known about their efficacy in the mucosal immune compartment. In this sub-investigation of the ongoing STAR-SIGN study, we present the first analysis of mucosal immunity elicited by XBB.1.5 mRNA vaccines in immunocompromised patients with IBD. Methods: IgG and IgA antibodies targeting the receptor-binding domain of the SARS-CoV-2 JN.1 variant were quantified longitudinally in the saliva of IBD patients using the multiplex immunoassay MultiCoV-Ab. Antibody levels were quantified before and 2–4 weeks after vaccination with XBB.1.5 mRNA vaccines. All patients previously received three doses with original COVID-19 vaccines. Results: Mucosal IgG antibodies were readily induced by XBB.1.5 mRNA vaccines (p = 0.0013 comparing pre- and post-vaccination levels). However, mucosal IgA levels were comparable before and after vaccination (p = 0.8233). Consequently, mucosal IgG and IgA antibody levels correlated only moderately before and after immunization (pre-vaccination: r = 0.5294; p = 0.0239; post-vaccination: r = 0.4863; p = 0.0407). Contrary to a previous report in healthy individuals, vaccination did not induce serum IgA in patients with IBD (p = 0.5841 comparing pre- and post-vaccination levels). These data suggest that COVID-19 mRNA vaccines fail to elicit mucosal IgA in patients with IBD. Conclusions: Since mucosal IgA plays a pivotal role in infection control, the lack of IgA induction indicates that patients lack sufficient protection against SARS-CoV-2 infections which warrants the development of mucosal COVID-19 vaccines. Full article
Show Figures

Figure 1

12 pages, 1494 KiB  
Article
Breakthrough Infection After a Primary Series of COVID-19 Vaccination Induces Stronger Humoral Immunity and Equivalent Cellular Immunity to the Spike Protein Compared with Booster Shots
by Yoshifumi Uwamino, Takashi Yokoyama, Yasunori Sato, Shiho Tanaka, Yuka Kamoshita, Ayako Shibata, Toshinobu Kurafuji, Akiko Tanabe, Tomoko Arai, Akemi Ohno, Ho Namkoong, Tomoyasu Nishimura, Masatoshi Wakui, Mitsuru Murata, Naoki Hasegawa and Hiromichi Matsushita
Vaccines 2025, 13(7), 751; https://doi.org/10.3390/vaccines13070751 - 13 Jul 2025
Viewed by 431
Abstract
Background: The long-term immune implications of administering more than four doses of COVID-19 vaccine and the impact of breakthrough infections are not fully understood. Research Design and Methods: We conducted a follow-up cohort study on Japanese healthcare workers who received more than three [...] Read more.
Background: The long-term immune implications of administering more than four doses of COVID-19 vaccine and the impact of breakthrough infections are not fully understood. Research Design and Methods: We conducted a follow-up cohort study on Japanese healthcare workers who received more than three doses of the BNT162b2 vaccine. We assessed both the anti-SARS-CoV-2 antibody titer and cellular immunity in 429 participants and investigated the numbers, types, and brands of COVID-19 vaccines administered, as well as the episodes of COVID-19 infections after the third dose. Results: Individuals who received three total doses of vaccines with BTI episodes demonstrated higher antibody titers than those who received four total doses of vaccines with no BTIs. The cellular immune responses between these two groups were comparable. Conclusions: These findings suggest that BTIs occurring after the primary series of COVID-19 vaccinations (first to third dose) induced humoral immunity to the spike protein that is greater than that induced by booster doses (fourth or fifth dose) and elicit cellular immunity to the spike protein comparable to that of booster doses. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

11 pages, 662 KiB  
Article
Antibody Responses Following Primary Immunization with the Recombinant Herpes Zoster Vaccine (Shingrix®) in VZV Seronegative Immunocompromised Adults
by Andrea Wessely, Ines Zwazl, Melita Poturica, Lukas Weseslindtner, Michael Kundi, Ursula Wiedermann and Angelika Wagner
Vaccines 2025, 13(7), 737; https://doi.org/10.3390/vaccines13070737 - 8 Jul 2025
Viewed by 523
Abstract
Background: Immunocompromised patients are at risk of severe varicella zoster virus (VZV) infection and reactivation. In VZV seronegative immunocompromised persons, live-attenuated VZV vaccination is contraindicated, thus the recombinant herpes zoster vaccine (rHZV) remains a safe alternative, although an off-label application. Yet, data on [...] Read more.
Background: Immunocompromised patients are at risk of severe varicella zoster virus (VZV) infection and reactivation. In VZV seronegative immunocompromised persons, live-attenuated VZV vaccination is contraindicated, thus the recombinant herpes zoster vaccine (rHZV) remains a safe alternative, although an off-label application. Yet, data on the induction of a VZV-specific immune response in immunocompromised individuals with VZV-specific IgG below the assay’s cut-off are only available for patients after solid-organ transplantation (SOT). Methods: We retrospectively analyzed the induction of VZV-specific IgG antibody levels after vaccination with rHZV in immunocompromised patients who previously tested anti-VZV-IgG negative between March 2018 and January 2024. Results: Of 952 vaccinees screened that received 2 or 3 doses rHZV, depending on the underlying disease, 33 patients (median age 53.0; 51.5% female) with either hematopoietic stem cell transplantation (82%) or high-grade immunosuppressive treatment (18%) fulfilled the inclusion criteria. Upon rHZV vaccination, 88% (29/33) individuals mounted a significant antibody response exceeding the assay’s cut-off level for seropositivity (p < 0.0001). We detected higher geometric mean antibody concentrations after three compared to two doses. However, 12% remained below the assay’s cut-off level and were therefore considered non-responsive. Conclusions: The rHZV is immunogenic in VZV-seronegative immunocompromised individuals and therefore presents a valid option to induce seroconversion. However, antibody testing in high-risk groups should be considered to identify humoral non- and low responders. Full article
(This article belongs to the Special Issue Varicella and Zoster Vaccination)
Show Figures

Figure 1

11 pages, 538 KiB  
Article
COVID-19 Vaccine Response in Allo-HSCT Recipients: Insights from a Real-World Prospective Cohort Study
by Emine Merve Savaş, Şeyma Yıldız, Zübeyde Nur Özkurt, Zehra Baltacı, Özlem Güzel Tunçcan, Zeynep Arzu Yeğin, Kayhan Çağlar, Nurdan Köktürk, Gonca Erbaş, Gülendam Bozdayı and Münci Yağcı
Vaccines 2025, 13(7), 726; https://doi.org/10.3390/vaccines13070726 - 3 Jul 2025
Viewed by 458
Abstract
Background: Allogeneic hematopoietic stem cell transplant (Allo-HSCT) recipients are still at increased risk of severe COVID-19 infection. Vaccination is a critical strategy to protect this population. This real-world prospective cohort study aimed to evaluate the immune response and clinical outcomes of COVID-19 vaccines [...] Read more.
Background: Allogeneic hematopoietic stem cell transplant (Allo-HSCT) recipients are still at increased risk of severe COVID-19 infection. Vaccination is a critical strategy to protect this population. This real-world prospective cohort study aimed to evaluate the immune response and clinical outcomes of COVID-19 vaccines in Allo-HSCT recipients. Methods: Allo-HSCT recipients (median age: 48 years) who received either the BNT162b2 or CoronaVac vaccines were included. Antibodies against the SARS-CoV-2 spike protein were quantitatively measured using the chemiluminescent microparticle immunoassay. Patient- and vaccine-related factors affecting antibody responses were analyzed. Adverse events, including graft-versus-host disease (GVHD) and post-vaccine infections, were recorded. Results: Among 95 Allo-HSCT recipients, 86.3% achieved adequate antibody responses following COVID-19 vaccination. Patients receiving ≥3 vaccine doses showed significantly higher antibody titers compared to those with only 2 doses (OR: 0.11; 95% CI: 0.02–0.53; p = 0.006 **). The use of Ruxolitinib or Ibrutinib was associate with increased odds of low antibody response (OR: 38.39; 95% CI: 3.14–468.95; p = 0.004 **). Hypogammaglobulinemia (low serum IgG levels) was associated with a reduced antibody response (OR: 0.17; 95% CI: 0.03–0.96; p = 0.045 *), while no significant correlation was found between serum IgA levels and antibody responses (p = 0.672). Three cases of post-vaccine GVHD were observed, and no fatalities related to COVID-19 occurred during the study. Conclusions: COVID-19 vaccination is safe and effective in Allo-HSCT recipients, with stronger responses especially following ≥3 vaccine doses. Patients receiving GVHD treatment or with hypogammaglobulinemia exhibited impaired responses, emphasizing the need for tailored vaccination strategies and close monitoring in this population. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

14 pages, 2212 KiB  
Article
Long COVID and Its Impacts: A Case–Control Study in Brazil
by Cristina M. Ruas, Maria Laura Silva, Ana L. G. F. Figueiredo, Amanda P. de Alencar, Samuel de S. Melo, Geovani F. de Castro, Natália V. Carobin, Melina A. Cordeiro, Janete F. R. Aguirre, Amanda F. M. de Oliveira and Adriano de P. Sabino
Biomedicines 2025, 13(7), 1615; https://doi.org/10.3390/biomedicines13071615 - 1 Jul 2025
Viewed by 422
Abstract
Introduction: Long COVID, or post-COVID-19 syndrome, refers to a set of persistent symptoms following SARS-CoV-2 infection without another identifiable cause. Studies indicate that symptoms can last for up to two years and affect multiple body systems. Objective: The objective of this study is [...] Read more.
Introduction: Long COVID, or post-COVID-19 syndrome, refers to a set of persistent symptoms following SARS-CoV-2 infection without another identifiable cause. Studies indicate that symptoms can last for up to two years and affect multiple body systems. Objective: The objective of this study is to compare symptom prevalence between infected individuals pre and post-COVID-19 and non-infected individuals in a population from Southeastern Brazil. Materials and Methods: A case–control study was conducted with participants from the MonitoraCovid program in a university in Brazil. The study included adults who responded to a questionnaire about long COVID symptoms. Data were collected virtually between October 2023 and May 2024. Results: Of the 2886 individuals eligible for analysis, 75.5% reported having been positive for COVID-19. Most participants were vaccinated, with 82.99% receiving two doses. In the pre and post comparison, individuals who had COVID-19 were more likely to report increased symptoms after infection, with 95.5% of assessed conditions worsening, particularly cognitive and respiratory issues. A comparison between those who had and had not been infected with COVID-19 showed that only 6.67% of symptoms were more prevalent in the infected group. The most significant post-COVID-19 symptoms included memory problems, fatigue, and shortness of breath, though some conditions, such as anxiety and sleep disturbances, were less common among those who had COVID-19. Conclusions: The findings reinforce that long COVID significantly impacts cognitive health, highlighting the importance of monitoring previously infected individuals. The study also emphasizes the need for further research in Global South contexts to better understand the long-term implications of COVID-19. Full article
Show Figures

Figure 1

Back to TopTop