Hepatitis C Virus-Core Antigen: Implications in Diagnostic, Treatment Monitoring and Clinical Outcomes.

The hepatitis C virus (HCV) infection, a global health concern, can lead to chronic liver disease. The HCV core antigen (HCVcAg), a viral protein essential for replication, offers a cost-effective alternative to HCV RNA testing, particularly in resource-limited settings. This review explores the significance of HCVcAg, a key protein in the hepatitis C virus, examining its structure, function, and role in the viral life cycle.

Seroprevalence of antibodies against diphtheria, tetanus, and pertussis across various age groups during the post-COVID-19 pandemic period in Chonburi Province, Thailand.

Background: Limited data exists regarding population immunity against diphtheria, tetanus, and pertussis in Thailand during the post-COVID-19 pandemic period. This study aimed to evaluate the age-specific seroprevalence of anti-diphtheria toxoid (anti-DT) IgG, anti-tetanus toxoid (anti-TT) IgG, and anti-pertussis toxin (anti-PT) IgG in individuals across diverse age groups in Chonburi province, Thailand following the COVID-19 pandemic.

Methods: Between October 2022 and January 2023, a total of 657 participants from Chonburi Province, Thailand, were included in this study.

Long-Term Dynamic Changes in Hybrid Immunity over Six Months after Inactivated and Adenoviral Vector Vaccination in Individuals with Previous SARS-CoV-2 Infection.

Numerous studies have largely focused on short-term immunogenicity in recovered individuals post mRNA vaccination. However, understanding the long-term durability, particularly in inactivated and adenoviral vectored vaccines, remains limited. We evaluated antibody responses, omicron variant neutralization, and IFN-γ responses in 119 previously infected individuals vaccinated with CoronaVac or ChAdOx1 up to six months post-vaccination.

Real-World Study: Hybrid Immunity against SARS-CoV-2 Influences the Antibody Levels and Persistency Lasting More than One Year.

This study investigated the impact of hybrid immunity on antibody responses in the participants who received two to seven doses of the COVID-19 vaccine. The study was conducted between April and June 2023. Out of 771 serum samples analyzed, 71.

Seroprevalence of SARS-CoV-2 anti-nucleocapsid total Ig, anti-RBD IgG antibodies, and infection in Thailand: a cross-sectional survey from October 2022 to January 2023.

Seroprevalence studies on SARS-CoV-2 are essential for estimating actual prevalence rates of infection and vaccination in communities. This study evaluated infection rates based on total anti-nucleocapsid immunoglobulin (N) and/or infection history. We determined the seroprevalence of anti-receptor binding domain (RBD) antibodies across age groups.

SARS-CoV-2 Antibody Dynamics after COVID-19 Vaccination and Infection: A Real-World Cross-Sectional Analysis.

The Coronavirus disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), continues to surge despite the widespread use of vaccination. In Thailand, more than 77% and 39% of the population received two doses and three doses of COVID-19 vaccines as of December 2022, respectively. In addition, during the Omicron predominant period in 2022, more than 70% of Thai individuals have been infected.

Investigation of the Molecular Epidemiology and Evolution of Circulating Severe Acute Respiratory Syndrome Coronavirus 2 in Thailand from 2020 to 2022 via Next-Generation Sequencing.

Coronavirus disease 2019 (COVID-19) is an infectious condition caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which surfaced in Thailand in early 2020. The current study investigated the SARS-CoV-2 lineages circulating in Thailand and their evolutionary history. Complete genome sequencing of 210 SARS-CoV-2 samples collected from collaborating hospitals and the Institute of Urban Disease Control and Prevention over two years, from December 2020 to July 2022, was performed using next-generation sequencing technology.

Evaluation of Anti-S1 IgA Response to Different COVID-19 Vaccination Regimens.

IgA plays a crucial role in early virus neutralization. To identify the IgA stimulation by COVID-19 vaccine, this study aimed to evaluate the level of anti-S1 IgA in the serum of participants immunized with different COVID-19 vaccination regimens. Sera from 567 eligible participants vaccinated with two, three, or four doses of different types of COVID-19 vaccine were recruited.

Seroprevalence of anti-SARS-CoV-2 antibodies and associated factors among household contacts of COVID-19 confirmed cases in Bangkok, Thailand.

Background: High COVID-19 transmission among household (HH) contacts of infected cases were reported with seroprevalence varying from 5.5% to 57.2% worldwide.

The Fourth Dose of mRNA COVID-19 Vaccine Following 12 Different Three-Dose Regimens: Safety and Immunogenicity to Omicron BA.4/BA.5.

The aim of this study is to investigate the reactogenicity and immunogenicity of the fourth dose using monovalent mRNA vaccines after different three-dose regimens and to compare the 30 µg BNT162b2 and 50 µg mRNA-1273 vaccines. This prospective cohort study was conducted between June and October 2022. The self-recorded reactogenicity was evaluated on the subsequent 7 days after a fourth dose.

Evolutionary and Genetic Recombination Analyses of Coxsackievirus A6 Variants Associated with Hand, Foot, and Mouth Disease Outbreaks in Thailand between 2019 and 2022.

Coxsackievirus (CV)-A6 infections cause hand, foot, and mouth disease (HFMD) in children and adults. Despite the serious public health threat presented by CV-A6 infections, our understanding of the mechanisms by which new CV-A6 strains emerge remains limited. This study investigated the molecular epidemiological trends, evolutionary dynamics, and recombination characteristics of CV-A6-associated HFMD in Thailand between 2019 and 2022.

Molecular characterisation and tracking of severe acute respiratory syndrome coronavirus 2 in Thailand, 2020-2022.

The global COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in China in December 2019. To date, there have been approximately 3.4 million reported cases of COVID-19 and over 24,000 deaths in Thailand.

Safety and immunogenicity of a third dose of COVID-19 protein subunit vaccine (Covovax) after homologous and heterologous two-dose regimens.

Objectives: To report the safety and immunogenicity profile of a protein subunit vaccine (Covovax) given as a third (booster) dose to individuals primed with different primary vaccine regimens.

Methods: A third dose was administered to individuals with an interval range of 3-10 months after the second dose. The four groups were classified according to their primary vaccine regimens, including two-dose BBIBP-CorV, AZD1222, BNT162b2, and CoronaVac/AZD1222.

Immunogenicity of ChAdOx1-nCoV-19 vaccine in solid malignancy patients by treatment regimen versus healthy controls: A prospective, multicenter observational study.

Background: Limited data exists regarding the efficacy of ChAdOx1-nCoV-19 vaccine against Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) in solid cancer patients. We aimed to assess the immunogenicity of the ChAdOx1-nCoV-19 vaccine and the impact of different anticancer therapies for solid malignancies on immune response.

Methods: This prospective, longitudinal observational study of immunogenicity following ChAdOx1-nCoV-19 vaccination among 385 solid cancer patients on active cancer treatment was conducted in two oncology centers.

Strong Correlations between the Binding Antibodies against Wild-Type and Neutralizing Antibodies against Omicron BA.1 and BA.2 Variants of SARS-CoV-2 in Individuals Following Booster (Third-Dose) Vaccination.

This study examined the neutralizing activity and receptor-binding domain (RBD) antibody levels against wild-type and omicron BA.1 and BA.2 variants in individuals who received three doses of COVID-19 vaccination.

Immunogenicity Following Two Doses of the BBIBP-CorV Vaccine and a Third Booster Dose with a Viral Vector and mRNA COVID-19 Vaccines against Delta and Omicron Variants in Prime Immunized Adults with Two Doses of the BBIBP-CorV Vaccine.

Coronavirus disease 2019 (COVID-19) booster vaccination is being comprehensively evaluated globally due to waning immunity and the emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Therefore, this study aimed to evaluate antibody responses in individuals vaccinated with two doses of the BBIBP-CorV vaccine and to explore the boosting effect of the different vaccine platforms in BBIBP-CorV-primed healthy adults, including a viral vector vaccine (AZD122) and mRNA vaccines (BNT162b2 and mRNA-1273). The results showed that in the BBIBP-CorV prime group, the total receptor-binding domain (RBD) immunoglobulin (Ig) and anti-RBD IgG levels waned significantly at three months after receiving the second dose.

Vaccine-Related adverse events following AZD1222 (ChAdOx1-nCoV-19) Covid-19 vaccine in solid malignancy patients receiving cancer treatment, as compared to age-matched healthy controls.

The study aimed to evaluate vaccine-related adverse events (VRAEs) following ChAdOx1-nCoV-19 vaccine in solid cancer patients receiving treatment compared to healthy controls. 399 cancer patients and 90 healthy volunteers were enrolled. In the overall population, the incidence of VRAEs was significantly lower in cancer patients than in healthy volunteers (57% vs 80%,  < .

Immunogenicity of heterologous inactivated and adenoviral-vectored COVID-19 vaccine: Real-world data.

Limited data are available on the responses to heterologous vaccine regimens for SARS-CoV-2, especially among countries using inactivated and adenoviral-vectored vaccines. A total of 77 participants who received heterologous inactivated COVID-19 vaccine (CoronaVac) and adenoviral-vectored vaccine (AZD1222) were enrolled in our study. There were two comparison groups vaccinated with the homologous CoronaVac (N = 79) and AZD1222 (N = 78) regimen.

Long-term persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific and neutralizing antibodies in recovered COVID-19 patients.

Understanding antibody responses after natural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can guide the coronavirus disease 2019 (COVID-19) vaccine schedule, especially in resource-limited settings. This study aimed to assess the dynamics of SARS-CoV-2 antibodies, including anti-spike protein 1 (S1) immunoglobulin (Ig)G, anti-receptor-binding domain (RBD) total Ig, anti-S1 IgA, and neutralizing antibody against wild-type SARS-CoV-2 over time in a cohort of patients who were previously infected with the wild-type SARS-CoV-2. Between March and May 2020, 531 individuals with virologically confirmed cases of wild-type SARS-CoV-2 infection were enrolled in our immunological study.

COVID-19 Breakthrough Infection after Inactivated Vaccine Induced Robust Antibody Responses and Cross-Neutralization of SARS-CoV-2 Variants, but Less Immunity against Omicron.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and the waning of immunity in vaccinated individuals is resulting in increased numbers of SARS-CoV-2 breakthrough infections. This study investigated binding antibody responses and neutralizing activities against SARS-CoV-2 variants, in patients with COVID-19 who had been fully vaccinated with CoronaVac ( = 77), individuals who had been fully vaccinated with CoronaVac but had not contracted COVID-19 ( = 170), and individuals who had received AZD1222 as a third vaccination ( = 210). Breakthrough infection was generally detected approximately 88 days after the second CoronaVac vaccination (interquartile range 68-100 days).