Ammar Abdurrahman Hasyim

Dr. Ammar Abdurrahman Hasyim

Laboratory of Vaccinology and Applied Immunology, Kanazawa University, Kanazawa, Ishikawa, Japan
orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 April 2025 in Journal of Fungi
Verified
Journal Article
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ARAnna Rozaliyani
Anna Rozaliyani
Findra SetianingrumFindra Setianingrum
Findra Setianingrum
FIFathiyah Isbaniah
Fathiyah Isbaniah
HAHeidy Agustin
Heidy Agustin
RHRaden Rara Diah Handayani
Raden Rara Diah Handayani
DDDavid W. Denning
David W. Denning
Background: A significant complication among post-tuberculosis patients is chronic pulmonary aspergillosis (CPA), with prevalence and outcomes varying by region. This study aimed to explore the epidemiology, clinical characteristics, and microbiological profiles of 219 post-tuberculosis patients with persistent respiratory symptoms and lung cavities in Indonesia. Methods: The patients were divided into CPA (n = 144) and non-CPA (n = 75) groups. This cross-sectional study diagnosed CPA in post-tuberculosis patients using ERS/ESCMID criteria, integrating clinical, radiological, and fungal assessments. Serological tests for Aspergillus-specific IgG were conducted using immunochromatographic (ICT) and ELISA on serum samples. Sputum specimens were used in parallel for fungal culture, and radiological evaluations (e.g., chest X-rays or CT scans) were performed to identify typical CPA features such as cavitation and fibrosis. Results: Persistent cough was significantly more common in CPA patients (83.3%, p = 0.015), highlighting its role as a clinical indicator for CPA. Radiological infiltrates were found in 165 patients (75.3%); critical diagnostic markers of CPA were cavitation and pericavitary fibrosis. Aspergillus-specific IgG testing demonstrated high diagnostic utility, with positivity rates of 69.4% for ICT and 63.2% for ELISA among CPA patients. Among those with infiltrates, a positive Aspergillus culture was not more common (p > 0.05), whereas Aspergillus IgG was more often raised (p = 0.037), as was a positive ICT (p = 0.021). Regional analysis revealed a higher CPA burden in Region 1 (75%) compared to Region 2 (56%, p = 0.003), with Aspergillus fumigatus and Aspergillus niger predominating in Region 1. Conclusions: These findings highlight the importance of comprehensive approaches and region-specific CPA management strategies in Indonesia.

21 September 2023 in Antibodies
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Journal Article
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SNSitti Nurisyah
Sitti Nurisyah
MIMitsuhiro Iyori
Mitsuhiro Iyori
Ammar Abdurrahman HasyimAmmar Abdurrahman Hasyim
Ammar Abdurrahman Hasyim
ASAkihiko Sakamoto
Akihiko Sakamoto
HHHinata Hashimoto
Hinata Hashimoto
YYYenni Yusuf
Yenni Yusuf
Background: To fight the COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also by vaccination. The effect of COVID-19 vaccination on previously infected persons is debatable. Methods: A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons—with and without COVID-19 pre-infection. The sera were analyzed for the anti-receptor binding domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays. Results: Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection and vaccinated naïve individuals (Spearman correlation coefficient (r) = −0.8558; 95% CI, −0.9259 to −0.7288), p < 0.0001 vs. −0.7855; 95% CI, −0.8877 to −0.6096, p < 0.0001 and −0.581; 95% CI, −0.7679 to −0.3028, p = 0.0002, respectively), indicating the capacity to neutralize the virus is most superior by infection alone. Conclusions: Vaccines induce anti-RBD titers as high as the natural infection with lower neutralization capacity, and it does not boost immunity in pre-infected persons.

10 October 2024 in Vaccines
Verified
Journal Article
Open access
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KZKartika Hardianti Zainal
Kartika Hardianti Zainal
Ammar Abdurrahman HasyimAmmar Abdurrahman Hasyim
Ammar Abdurrahman Hasyim
YYYutaro Yamamoto
Yutaro Yamamoto
TMTetsushi Mizuno
Tetsushi Mizuno
YSYuna Sato
Yuna Sato
SYShigeto Yoshida
Shigeto Yoshida
Background/Objectives: We developed a multistage Plasmodium falciparum vaccine using a heterologous prime-boost immunization strategy. This involved priming with a highly attenuated, replication-competent vaccinia virus strain LC16m8Δ (m8Δ) and boosting with adeno-associated virus type 1 (AAV1). This approach demonstrated 100% efficacy in both protection and transmission-blocking in a murine model. In this study, we compared our LC16m8∆/AAV1 vaccine, which harbors a gene encoding Pfs25-PfCSP fusion protein, to RTS,S/AS01 (RTS,S) in terms of immune responses, protective efficacy, and transmission-blocking activity (TBA) in murine models. Methods: Mice were immunized following prime-boost vaccine regimens m8∆/AAV1 or RTS,S and challenged with transgenic Plasmodium berghei parasites. Immune responses were assessed via ELISA, and TB efficacy was evaluated using direct feeding assays. Results: m8∆/AAV1 provided complete protection (100%) in BALB/c mice and moderate (40%) protection in C57BL/6 mice, similar to RTS,S. Unlike RTS,S’s narrow focus (repeat region), m8∆/AAV1 triggered antibodies for all PfCSP regions (N-terminus, repeat, and C-terminus) with balanced Th1/Th2 ratios. Regarding transmission blockade, serum from m8∆/AAV1-vaccinated BALB/c mice achieved substantial transmission-reducing activity (TRA = 83.02%) and TB activity (TBA = 38.98%)—attributes not observed with RTS,S. Furthermore, m8∆/AAV1 demonstrated durable TB efficacy (94.31% TRA and 63.79% TBA) 100 days post-immunization. Conclusions: These results highlight m8∆/AAV1′s dual action in preventing sporozoite invasion and onward transmission, a significant advantage over RTS,S. Consequently, m8∆/AAV1 represents an alternative and a promising vaccine candidate that can enhance malaria control and elimination strategies.

1 January 2025 in Narra J
Verified
Journal Article
Open access
SNSitti Nurisyah
Sitti Nurisyah
MIMitsuhiro Iyori
Mitsuhiro Iyori
Ammar Abdurrahman HasyimAmmar Abdurrahman Hasyim
Ammar Abdurrahman Hasyim
KAKhaeriah Amru
Khaeriah Amru
KIKei Itani
Kei Itani
YYYenni Yusuf
Yenni Yusuf
Evaluating long-term immunity after COVID-19 infection and vaccination is critical for managing potential outbreaks. The aim of this study was to develop a cost-effective in-house enzyme-linked immunosorbent assay (ELISA) based on Escherichia coli-expressed SARS-CoV-2 spike protein (E-S1) for antibody detection and to evaluate its performance. The system was validated by comparing the in-house ELISA results with those obtained using a commercial ELISA with HEK293-expressed spike protein (H-S1). Recombinant SARS-CoV-2 spike protein was produced in E. coli, purified, and validated for antigenicity via ELISA. Indirect ELISAs with both E-S1 and H-S1 antigens were performed on 386 serum samples from COVID-19 survivors, vaccinated individuals, and pre-pandemic controls collected at different time points. The E-S1 ELISA showed a statistically significant but weak correlation with H-S1 ELISA across all samples (r=0.205; p=0.0001). Stronger correlations were observed among vaccinated individuals with prior infection on day 90 (r=0.6017; p<0.001) and in naïve vaccine recipients on day 30 (r=0.5361; p=0.0003). Pre-pandemic sera from a rural population in Sumba Island exhibited high background reactivity in E-S1 ELISA, likely due to anti-E. coli antibodies, while urban pre-pandemic sera from Jakarta showed a stronger correlation with H-S1 ELISA. This suggests potential regional or immune background differences influencing assay performance. Although E-S1 retained antigenic properties, its diagnostic utility is limited by non-specific reactivity and reduced sensitivity compared to H-S1. In conclusion, E. coli expression systems may not be ideal for producing spike protein-based ELISA antigens specific to SARS-CoV-2. Alternative expression systems, such as human or baculovirus, could enhance diagnostic accuracy and specificity for COVID-19 antibody detection.

8 August 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
SNSitti Nurisyah
Sitti Nurisyah
MIMitsuhiro Iyori
Mitsuhiro Iyori
Ammar Abdurrahman HasyimAmmar Abdurrahman Hasyim
Ammar Abdurrahman Hasyim
ASAkihiko Sakamoto
Akihiko Sakamoto
HHHinata Hashimoto
Hinata Hashimoto
YYYenni Yusuf
Yenni Yusuf
(1) Background: To fight for COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also vaccination. Controversies exist about the effect of COVID-19 vaccination on previously infected persons; (2) Methods: A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons--with and without COVID-19 pre-infection. The sera were analyzed for the anti-Receptor Binding Domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays; (3) Results; Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection (Spearman correlation coefficient (r) = -0.8558; 95% CI, -0.9259 to -0.7288), p <0.0001 vs -0. 581; 95% CI, -0.7679 to -0.3028; p = 0.0002, respectively), indicating the capacity to neutralize the virus is better among the unvaccinated individuals. (4) Conclusions: Vaccines induced anti-RBD titers as high as the natural infection with lower neutralization capacity, and it did not boost the immunity in pre-infected persons.

18 September 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
KZKartika Hardianti Zainal
Kartika Hardianti Zainal
Ammar Abdurrahman HasyimAmmar Abdurrahman Hasyim
Ammar Abdurrahman Hasyim
YYYutaro Yamamoto
Yutaro Yamamoto
TMTetsushi Mizuno
Tetsushi Mizuno
YSYuna Sato
Yuna Sato
SYShigeto Yoshida
Shigeto Yoshida
Background/objectives: We developed a multistage Plasmodium falciparum vaccine using a heterologous prime-boost immunization strategy. This involved priming with a highly attenuated, replication-competent vaccinia virus strain LC16m8Δ (m8Δ) and boosting with adeno-associated virus type 1 (AAV1). This approach demonstrated 100% efficacy in both protection and transmission-blocking in a murine model. In this study, we compared our LC16m8∆/AAV1 vaccine, which harbors a gene encoding Pfs25-PfCSP fusion protein, to RTS,S/AS01 (RTS,S) in terms of immune responses, protective efficacy, and TB activity in murine models. Methods: Mice were immunized following prime-boost vaccine regimens m8∆/AAV1 or RTS,S and challenged with transgenic Plasmodium berghei parasites. Immune responses were assessed via ELISA, and TB efficacy was evaluated using direct feeding assays. Results: m8∆/AAV1 provided complete protection (100%) in BALB/c mice and moderate (40%) protection in C57BL/6 mice, similar to RTS,S. Unlike RTS,S’s narrow focus (repeat region), m8∆/AAV1 triggered antibodies for all PfCSP regions (N-terminus, repeat, and C-terminus) with balanced Th1/Th2 ratios. Regarding transmission blockade, serum from m8∆/AAV1-vaccinated BALB/c mice achieved substantial transmission-reducing activity (TRA = 83.02%) and TB activity (TBA = 38.98%)—attributes not observed with RTS,S. Furthermore, m8∆/AAV1 demonstrated durable TB efficacy (94.31% TRA and 63.79% TBA) 100 days post-immunization. Conclusions: These results highlight m8∆/AAV1's dual action in preventing sporozoite invasion and onward transmission, a significant advantage over RTS,S. Consequently, m8∆/AAV1 represents an alternative and a promising vaccine candidate that can enhance malaria control and elimination strategies.