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1.
Clin Immunol ; 251: 109342, 2023 06.
Article in English | MEDLINE | ID: covidwho-2303610

ABSTRACT

BACKGROUND: Information regarding the heterologous prime-boost COVID vaccination has been fully elucidated. The study aimed to evaluate both humoral, cellular immunity and cross-reactivity against variants after heterologous vaccination. METHODS: We recruited healthcare workers previously primed with Oxford/AstraZeneca ChAdOx1-S vaccines and boosted with Moderna mRNA-1273 vaccine boost to evaluate the immunological response. Assay used: anti-spike RBD antibody, surrogate virus neutralizing antibody and interferon-γ release assay. RESULTS: All participants exhibited higher humoral and cellular immune response after the booster regardless of prior antibody level, but those with higher antibody level demonstrated stronger booster response, especially against omicron BA.1 and BA.2 variants. The pre-booster IFN-γ release by CD4+ T cells correlates with post-booster neutralizing antibody against BA.1 and BA.2 variant after adjustment with age and gender. CONCLUSIONS: A heterologous mRNA boost is highly immunogenic. The pre-existing neutralizing antibody level and CD4+ T cells response correlates with post-booster neutralization reactivity against the Omicron variant.


Subject(s)
COVID-19 , Immunity, Humoral , Humans , T-Lymphocytes , 2019-nCoV Vaccine mRNA-1273 , SARS-CoV-2 , COVID-19/prevention & control , Vaccination , Antibodies, Neutralizing , CD4-Positive T-Lymphocytes , Antibodies, Viral
3.
Diagnostics (Basel) ; 12(6)2022 Jun 06.
Article in English | MEDLINE | ID: covidwho-1884055

ABSTRACT

The COVID-19 pandemic has had an enormous impact on individuals, societies, and economies worldwide and has resulted in a significant loss of life worldwide [...].

4.
Vaccines (Basel) ; 10(2)2022 Feb 10.
Article in English | MEDLINE | ID: covidwho-1705620

ABSTRACT

As of August 2021, there have been over 200 million confirmed case of coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus and more than 4 million COVID-19-related deaths globally. Although real-time polymerase chain reaction is considered to be the primary method of detection for SARS-CoV-2 infection, the use of serological assays for detecting COVID-19 antibodies has been shown to be effective in aiding with diagnosis, particularly in patients who have recovered from the disease and those in later stages of infection. Since it has a high detection rate and few limitations compared to conventional enzyme-linked immunosorbent assay protocols, we used a lateral flow immunoassay as our diagnostic tool of choice. Since lateral flow immunoassay results interpreted by the naked eye may lead to erroneous diagnoses, we developed an innovative, portable device with the capacity to capture a high-resolution reflectance spectrum as a means of promoting diagnostic accuracy. We combined this spectrum-based device with commercial lateral flow immunoassays to detect the neutralizing antibody in serum samples collected from 30 COVID-19-infected patients (26 mild cases and four severe cases). The results of our approach, lateral flow immunoassays coupled with a spectrum-based reader, demonstrated a 0.989 area under the ROC curve, 100% sensitivity, 95.7% positive predictive value, 87.5% specificity, and 100% negative predictive value. As a result, our approach exhibited great value for neutralizing antibody detection. In addition to the above tests, we also tested plasma samples from 16 AstraZeneca-vaccinated (ChAdOx1nCoV-19) patients and compared our approach and enzyme-linked immunosorbent assay results to see whether our approach could be applied to vaccinated patients. The results showed a high correlation between these two approaches, indicating that the lateral flow immunoassay coupled with a spectrum-based reader is a feasible approach for diagnosing the presence of a neutralizing antibody in both COVID-19-infected and vaccinated patients.

5.
Front Immunol ; 13: 807454, 2022.
Article in English | MEDLINE | ID: covidwho-1686483

ABSTRACT

Background: Innate immunity, armed with pattern recognition receptors including Toll-like receptors (TLR), is critical for immune cell activation and the connection to anti-microbial adaptive immunity. However, information regarding the impact of age on the innate immunity in response to SARS-CoV2 adenovirus vector vaccines and its association with specific immune responses remains scarce. Methods: Fifteen subjects between 25-35 years (the young group) and five subjects between 60-70 years (the older adult group) were enrolled before ChAdOx1 nCoV-19 (AZD1222) vaccination. We determined activation markers and cytokine production of monocyte, natural killer (NK) cells and B cells ex vivo stimulated with TLR agonist (poly (I:C) for TLR3; LPS for TLR4; imiquimod for TLR7; CpG for TLR9) before vaccination and 3-5 days after each jab with flow cytometry. Anti-SARS-CoV2 neutralization antibody titers (surrogate virus neutralization tests, sVNTs) were measured using serum collected 2 months after the first jab and one month after full vaccination. Results: The older adult vaccinees had weaker vaccine-induced sVNTs than young vaccinees after 1st jab (47.2±19.3% vs. 21.2±22.2%, p value<0.05), but this difference became insignificant after the 2nd jab. Imiquimod, LPS and CpG strongly induced CD86 expression in IgD+CD27- naïve and IgD-CD27+ memory B cells in the young group. In contrast, only the IgD+ CD27- naïve B cells responded to these TLR agonists in the older adult group. Imiquimode strongly induced the CD86 expression in CD14+ monocytes in the young group but not in the older adult group. After vaccination, the young group had significantly higher IFN-γ expression in CD3- CD56dim NK cells after the 1st jab, whilst the older adult group had significantly higher IFN-γ and granzyme B expression in CD56bright NK cells after the 2nd jab (all p value <0.05). The IFN-γ expression in CD56dim and CD56bright NK cells after the first vaccination and CD86 expression in CD14+ monocyte and IgD-CD27-double-negative B cells after LPS and imiquimod stimulation correlated with vaccine-induced antibody responses. Conclusions: The innate immune responses after the first vaccination correlated with the neutralizing antibody production. Older people may have defective innate immune responses by TLR stimulation and weak or delayed innate immune activation profile after vaccination compared with young people.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , B-Lymphocytes/immunology , ChAdOx1 nCoV-19/immunology , Killer Cells, Natural/immunology , SARS-CoV-2/immunology , Adult , Aged , COVID-19/prevention & control , Female , Humans , Imiquimod/pharmacology , Immunity, Innate/immunology , Immunosenescence/immunology , Interferon-gamma/blood , Male , Middle Aged , Poly I-C/administration & dosage , Poly I-C/immunology , Toll-Like Receptors/immunology , Vaccination
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