Prevalence and incidence rates of tuberculosis in people with HIV during the coronavirus 2019 pandemic: a single center retrospective analysis.

BACKGROUND: Tuberculosis (TB) poses a significant risk to people with HIV (PWH), with heightened incidence and prevalence rates, especially in countries with a high TB burden. This study assesses the prevalence and incidence rates of TB among PWH during the COVID-19 pandemic, and on treatment outcomes in TB-HIV co-infections. METHODS: A retrospective study was conducted at Suddhavej Hospital, Faculty of Medicine, Mahasarakham University, Maha Sarakham, Thailand, from January 2020 to September 2023, involving newly diagnosed adult PWH. Data were collected on TB prevalence and incidence rates, with TB cases categorized as definite or possible. The primary outcomes were TB prevalence and incidence rates per 100,000 person-years of follow-up. RESULTS: Among 171 newly diagnosed PWH, the prevalence of TB was 5.85%, with an incidence rate of 4,568.71 per 100,000 person-years. All but one TB cases were diagnosed before antiretroviral therapy (ART) initiation. There was no incident TB during the follow-up period during ART. Nearly half of the TB cases required therapeutic trials without microbiological confirmation. CONCLUSIONS: The study revealed a high prevalence and incidence rate of TB among PWH during the COVID-19 pandemic, comparable to pre-pandemic rates in Thailand. The findings highlight the necessity of comprehensive TB screening prior to ART initiation and the cautious implementation of universal TB preventive therapy. The use of molecular diagnostics, in addition to symptom screening, can enhance TB diagnosis among PWH, though accessibility remains an issue in many regions.

Comparative Performance in the Detection of Four Coronavirus Genera from Human, Animal, and Environmental Specimens.

Emerging coronaviruses (CoVs) are understood to cause critical human and domestic animal diseases; the spillover from wildlife reservoirs can result in mild and severe respiratory illness in humans and domestic animals and can spread more readily in these naïve hosts. A low-cost CoV molecular method that can detect a variety of CoVs from humans, animals, and environmental specimens is an initial step to ensure the early identification of known and new viruses. We examine a collection of 50 human, 46 wastewater, 28 bat, and 17 avian archived specimens using 3 published pan-CoV PCR assays called Q-, W-, and X-CoV PCR, to compare the performance of each assay against four CoV genera. X-CoV PCR can detect all four CoV genera, but Q- and W-CoV PCR failed to detect δ-CoV. In total, 21 (42.0%), 9 (18.0%), and 21 (42.0%) of 50 human specimens and 30 (65.22%), 6 (13.04%), and 27 (58.70%) of 46 wastewater specimens were detected using Q-, W-, and X-CoV PCR assays, respectively. The X-CoV PCR assay has a comparable sensitivity to Q-CoV PCR in bat CoV detection. Combining Q- and X-CoV PCR assays can increase sensitivity and avoid false negative results in the early detection of novel CoVs.

An unusual diarrheal outbreak in the community in Eastern Thailand caused by Norovirus GII.3[P25].

BACKGROUND: Sentinel laboratory surveillance for diarrheal disease determined norovirus to be the most common cause of non-bacterial gastroenteritis in people during the COVID-19 pandemic in Thailand. An increase in patients presenting with diarrhea and vomiting in hospitals across Chanthaburi province between December 2021 and January 2022 led to the need for the identification of viral pathogens that may be responsible for the outbreak. METHODS: Fecal samples (rectal swabs or stool) from 93 patients, of which 65 patients were collected during the December 2021 to January 2022 outbreak, were collected and screened for viral infection by real-time RT-PCR. Positive samples for norovirus GII were then genotyped by targeted amplification and sequencing of partial polymerase and capsid genes. Full genome sequencing was performed from the predominant strain, GII.3[P25]. RESULTS: Norovirus was the most common virus detected in human fecal samples in this study. 39 of 65 outbreak samples (60%) and 3 of 28 (10%) non-outbreak samples were positive for norovirus genogroup II. One was positive for rotavirus, and one indicated co-infection with rotavirus and norovirus genogroups I and II. Nucleotide sequences of VP1 and RdRp gene were successfully obtained from 28 of 39 positive norovirus GII and used for dual-typing; 25/28 (89.3%) were GII.3, and 24/28 (85.7) were GII.P25, respectively. Norovirus GII.3[P25] was the predominant strain responsible for this outbreak. The full genome sequence of norovirus GII.3[P25] from our study is the first reported in Thailand and has 98.62% and 98.57% similarity to norovirus found in China in 2021 and the USA in 2022, respectively. We further demonstrate the presence of multiple co-circulating norovirus genotypes, including GII.21[P21], GII.17[P17], GII.3[P12] and GII.4[P31] in our study. CONCLUSIONS: An unusual diarrhea outbreak was found in December 2021 in eastern Thailand. Norovirus strain GII.3[P25] was the cause of the outbreak and was first detected in Thailand. The positive rate during GII.3[P25] outbreak was six times higher than sporadic cases (GII.4), and, atypically, adults were the primary infected population rather than children.

High Transmission Rates of Early Omicron Subvariant BA.2 in Bangkok, Thailand.

The emergence of Omicron as the fifth variant of concern within the SARS-CoV-2 pandemic in late 2021, characterized by its rapid transmission and distinct spike gene mutations, underscored the pressing need for cost-effective and efficient methods to detect viral variants, especially given their evolving nature. This study sought to address this need by assessing the effectiveness of two SARS-CoV-2 variant classification platforms based on RT-PCR and mass spectrometry. The primary aim was to differentiate between Delta, Omicron BA.1, and Omicron BA.2 variants using 618 COVID-19-positive samples collected from Bangkok patients between November 2011 and March 2022. The analysis revealed that both BA.1 and BA.2 variants exhibited significantly higher transmission rates, up to 2-3 times, when compared to the Delta variant. This research presents a cost-efficient approach to virus surveillance, enabling a quantitative evaluation of variant-specific public health implications, crucial for informing and adapting public health strategies.

Treatment Outcomes After Switching to Second-Line Anti-Retroviral Therapy: Results From the Thai National Treatment Program.

This study aimed to assess second-line antiretroviral therapy (ART) outcomes in a National HIV Treatment program. People living with HIV aged ≥18 years initiating first-line ART who switched to second-line protease inhibitor-based regimens from January 2008 to May 2019, with a minimum of 1-year follow-up were studied. The primary outcome was second-line treatment failure (two consecutive virological failure episodes (viral load ≥1000 copies/mL)). Of 318,506 PLH initiating ART, 29,015 (9.1%) switched to second-line regimens after a median (IQR) ART duration of 1.63 (0.60-3.59) years. Lost to follow-up (LTFU) occurred in 5316 (18.3%) of whom 1376 (5%) remained LTFU and alive; 4606 (15.9%) died. Cumulative second-line failure incidence was 9.8% at 6 years, more common in females, younger PLH those with lower switch CD4 cell counts. Multidisciplinary, innovative support systems are needed to improve second-line treatment outcomes, particularly those relating to modifiable risk factors.

Outcomes after switching to second line antiretroviral regimens in the Thai National Treatment programWe assessed the rates of virological failure, losses to follow-up and death in 29,015 people who switched to second line antiretroviral therapy in Thailand. The cumulative rate of virological failure was a 9.8% at 6 years, loss to follow-up occurred in 18.3% (5% who remained alive) and 15.9% died. Women and those with lower CD4 counts at switch had the highest risk of virological failure.

Long-term immunogenicity in previously vaccinated healthcare workers with inactivated virus vaccine after SARS-CoV-2 infection or booster vaccination.

Immunity against SARS-CoV-2 infection in vaccinated individuals varies based on the vaccine type, duration after vaccination or infection, and SARS-CoV-2 variant type. We conducted a prospective observational study to evaluate the immunogenicity of a booster vaccination with AZD1222 after two doses of CoronaVac (booster group) compared to individuals who had SARS-CoV-2 infection after receiving two doses of CoronaVac (infection group). We used a surrogate virus neutralization test (sVNT) to evaluate immunity against wild-type and Omicron variant (BA.1) at 3 and 6 months after infection or booster dose. Of the 89 participants, 41 were in the infection group, and 48 were in the booster group. At 3 months post-infection or booster vaccination, the median (IQR) sVNT against wild-type was 97.87 % (97.57-97.93 %) and 97.65 % (95.38-98.00 %), p = 0.66, respectively, while the sVNT against Omicron was 18.8 % (0-47.10 %) and 24.46 (11.69-35.47 %), p = 0.72 respectively. At 6 months, the median (IQR) sVNT against wild-type was 97.68 % (95.86-97.92 %) in the infection group, higher than 94.7 % (95.38-98.00 %) in the booster group (p = 0.03). Results showed no significant difference in immunity against wild-type and Omicron at 3 months between the two groups. However, the infection group exhibited better immunity than the booster group at 6 months.

SARS-CoV-2 Variants Detection Strategies in Wastewater Samples Collected in the Bangkok Metropolitan Region.

Wastewater surveillance is considered a promising approach for COVID-19 surveillance in communities. In this study, we collected wastewater samples between November 2020 and February 2022 from twenty-three sites in the Bangkok Metropolitan Region to detect the presence of SARS-CoV-2 and its variants for comparison to standard clinical sampling. A total of 215 wastewater samples were collected and tested for SARS-CoV-2 RNA by real-time PCR with three targeted genes (N, E, and ORF1ab); 102 samples were positive (42.5%). The SARS-CoV-2 variants were determined by a multiplex PCR MassARRAY assay to distinguish four SARS-CoV-2 variants, including Alpha, Beta, Delta, and Omicron. Multiple variants of Alpha-Delta and Delta-Omicron were detected in the wastewater samples in July 2021 and January 2022, respectively. These wastewater variant results mirrored the country data from clinical specimens deposited in GISAID. Our results demonstrated that wastewater surveillance using multiple signature mutation sites for SARS-CoV-2 variant detection is an appropriate strategy to monitor the presence of SARS-CoV-2 variants in the community at a low cost and with rapid turn-around time. However, it is essential to note that sequencing surveillance of wastewater samples should be considered complementary to whole genome sequencing of clinical samples to detect novel variants.

Simultaneous detection of omicron and other SARS-CoV-2 variants by multiplex PCR MassARRAY technology.

The rapid emergence of SARS-CoV-2 variants with high severity and transmutability adds further urgency for rapid and multiplex molecular testing to identify the variants. A nucleotide matrix-assisted laser-desorption-ionization time-of-flight mass spectrophotometry (MALDI-TOF MS)-based assay was developed (called point mutation array, PMA) to identify four major SARS-CoV-2 variants of concern (VOCs) including Alpha, Beta, Delta, and Omicron (namely PMA-ABDO) and differentiate Omicron subvariant (namely PMA-Omicron). PMA-ABDO and PMA-Omicron consist of 24 and 28 mutation sites of the spike gene. Both PMA panels specifically identified VOCs with as low as 10 viral copies/µl. The panel has shown a 100% concordant with the Next Generation Sequencing (NGS) results testing on 256 clinical specimens with real-time PCR cycle threshold (Ct) values less than 26. It showed a higher sensitivity over NGS; 25/28 samples were positive by PMA but not NGS in the clinical samples with PCR Ct higher than 26. Due to the mass of nucleotide used to differentiate between wild-type and mutation strains, the co-infection or recombination of multiple variants can be determined by the PMA method. This method is flexible in adding a new primer set to identify a new emerging mutation site among the current circulating VOCs and the turnaround time is less than 8 h. However, the spike gene sequencing or NGS retains the advantage of detecting newly emerged variants.

Telepharmacy during home isolation: drug-related problems and pharmaceutical care in COVID-19 patients receiving antiviral therapy in Thailand.

BACKGROUND: Home isolation has been proposed for coronavirus disease 2019 (COVID-19) patients with mild symptoms to avoid hospital overcrowding. This study aimed to describe the drug-related problems (DRPs) and the pharmaceutical care of home-isolating COVID-19 patients in Thailand. METHODS: Our cross-sectional study was undertaken from July 1 to September 30, 2021, at the King Chulalongkorn Memorial Hospital, Thailand. Patients who were ≥ 18 years old, were diagnosed with mild COVID-19 by real-time polymerase chain reaction (RT-PCR), and were able to isolate at home while receiving an antiviral agent and standard symptomatic treatment were enrolled. Infectious disease pharmacists provided a telepharmacy service on days 1 and 3 after the COVID-19 diagnosis. RESULTS: A total of 197 patients met the study criteria. Their median age was 45 years, and their most common underlying disease was hypertension (44.29%). All patients exhibited excellent anti-COVID-19 drug adherence. We identified 125 DRPs, including adverse reactions (68%), and the unnecessary use of products (62.40%). Moreover, 91 patients (46.19%) reported the use of supplements or herbs, with vitamin C being the main supplement (37.36%). Pharmacists provided 36 recommendations and received 33 questions from COVID-19 patients. CONCLUSIONS: Our study demonstrates that telepharmacy is an essential service for detecting and preventing DRPs in home-isolating COVID-19 patients.

Simultaneous Detection of Omicron and Other SARS-CoV-2 Variants by Multiplex PCR MassARRAY Technology.

The rapid emergence of SARS-CoV-2 variants with high severity and transmutability adds further urgency for rapid and multiplex molecular testing to identify the variants. A nucleotide matrix-assisted laser-desorption-ionization time-of-flight mass spectrophotometry (MALDI-TOF MS)-based assay was developed (called point mutation array, PMA) to identify four major SARS-CoV-2 variants of concern (VOCs) including Alpha, Beta, Delta, and Omicron (namely PMA-ABDO) and differentiate Omicron subvariant (namely PMA-Omicron). PMA-ABDO and PMA-Omicron consist of 24 and 28 mutation sites of the spike gene. Both PMA panels specifically identified VOCs with as low as 10 viral copies/ µl. The panel has shown a 100% concordant with the Next Generation Sequencing (NGS) results testing on 256 clinical specimens with real-time PCR cycle threshold (Ct) values less than 26. It showed a higher sensitivity over NGS; 25/28 samples were positive by PMA but not NGS in the clinical samples with PCR Ct higher than 26. Due to the mass of nucleotide used to differentiate between wild-type and mutation strains, the co-infection or recombination of multiple variants can be determined by the PMA method. This method is flexible in adding a new primer set to identify a new emerging mutation site among the current circulating VOCs and the turnaround time is less than 8 hours. However, the spike gene sequencing or NGS retains the advantage of detecting newly emerged variants.

Impact of SARS-CoV-2 infection on the profiles and responses of innate immune cells after recovery.

BACKGROUNDS: SARS-CoV-2 infection results in a broad spectrum of clinical outcomes, ranging from asymptomatic to severe symptoms and death. Most COVID-19 pathogenesis is associated with hyperinflammatory conditions driven primarily by myeloid cell lineages. The long-term effects of SARS-CoV-2 infection post recovery include various symptoms. METHODS: We performed a longitudinal study of the innate immune profiles 1 and 3 months after recovery in the Thai cohort by comparing patients with mild, moderate, and severe clinical symptoms using peripheral blood mononuclear cells (n = 62). RESULTS: Significant increases in the frequencies of monocytes compared to controls and NK cells compared to mild and moderate patients were observed in severe patients 1-3 months post recovery. Increased polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were observed in all recovered patients, even after 3 months. Increased IL-6 and TNFα levels in monocytes were observed 1 month after recovery in response to lipopolysaccharide (LPS) stimulation, while decreased CD86 and HLA-DR levels were observed regardless of stimulation. A multiplex analysis of serum cytokines performed at 1 month revealed that most innate cytokines, except for TNFα, IL4/IL-13 (Th2) and IFNγ (Th1), were elevated in recovered patients in a severity-dependent manner. Finally, the myelopoiesis cytokines G-CSF and GM-CSF were higher in all patient groups. Increased monocytes and IL-6- and TNFα-producing cells were significantly associated with long COVID-19 symptoms. CONCLUSIONS: These results reveal that COVID-19 infection influences the frequencies and functions of innate immune cells for up to 3 months after recovery, which may potentially lead to some of the long COVID symptoms.

SARS-CoV-2 Omicron variant emerged under immune selection.

The SARS-CoV-2 Omicron variant (B.1.1.529 lineage) escapes antibodies that neutralize the ancestral virus. We tested human serum panels from participants with differing infection and vaccination status using a multiplex surrogate virus neutralization assay targeting 20 sarbecoviruses. We found that bat and pangolin sarbecoviruses showed significantly less neutralization escape than the Omicron variant. We propose that SARS-CoV-2 variants have emerged under immune selection pressure and are evolving differently from animal sarbecoviruses.

Early switching of tenofovir disoproxil fumarate (TDF) in HIV-infected patients with TDF-induced nephrotoxicity: a prospective study.

Background: Tenofovir disoproxil fumarate (TDF) can induce proximal renal tubulopathy (PRT) and necessitate changes in treatment regimen. This prospective study aimed to compare tubular function recovery following early switching versus late switching of TDF in human immunodeficiency virus (HIV)-infected patients with TDF-induced PRT.Methods: For this prospective study, conducted during 2017-2019, we enrolled HIV-1-infected, virologically suppressed adults undergoing TDF-containing combination antiretroviral therapy. Patients were separated into a late-switching group (LSG) and an early-switching group (ESG). The LSG included patients having an estimated glomerular filtration rate (eGFR) decrease ≥25% from the pretreatment level or Fanconi syndrome. The ESG included patients having ≥2 of the following indicators of PRT: fractional excretion of phosphate (FEUP) ≥10%, low tubular maximum reabsorption of phosphate (TmP)/GFR, or uricosuria; fractional uric acid excretion ≥10%; urine protein-creatinine index (UPCI) ≥500 mg/g creatinine, normoglycemic glycosuria, or decrease in eGFR of 15%-24%. Recovery of proximal tubular function at 6 and 12 months after TDF discontinuation was assessed. Complete recovery was defined as normalization of all abnormal tubular markers.Results: Thirty-three HIV-infected patients were enrolled (70% male). Except for tubular function markers, baseline characteristics were not significantly different between the two groups. The proportion of patients having complete recovery was significantly higher in the ESG (p = 0.007, log-rank test). FEUP improved significantly in the ESG after TDF discontinuation; improvements of eGFR and UPCI were greater in the LSG. An eGFR change of 10% from baseline was the only independent predictor of failure to achieve complete recovery after switching. After median follow-up of 2.25 years post-trial, sustained recovery of eGFR within 5% of pre-TDF eGFR was achieved only in the ESG.Conclusions: Early-switching of TDF in HIV patients with PRT may allow complete recovery of proximal renal tubular function.

Homologous or Heterologous COVID-19 Booster Regimens Significantly Impact Sero-Neutralization of SARS-CoV-2 Virus and Its Variants.

We determined the levels of neutralizing antibodies against the SARS-CoV-2 ancestral strain, Delta and Omicron variants of concern (VOCs), in 125 healthcare workers who received CoronaVac as their primary vaccination and later received either a single ChAdOx1 or a combi-nation of two consecutive boosters using either two ChAdOx1 doses or a ChAdOx1 or BNT162b2 as the primary and second boosters, respectively, or two doses of BNT162b2. The titers 12 weeks after primary vaccination were inadequate to neutralize all strains. After a single ChAdOx1 booster, the levels of neutralization at Day 30 varied significantly, with only a small proportion of participants developing neutralizing titers against Omicron at Day 7 and 30. The two doses of ChAdOx1 as the booster induced the lowest activity. A combination ChAdOx1 and BNT162b2 induced greater neutralization than by two doses of ChAdOx1. Two doses of BNT162b2 as the booster had the maximal activity against Omicron VOC.

Use of qRT-PCR for SARS-CoV-2 sgRNA leader for the therapeutic plan: a preliminary report on 10 patients.

INTRODUCTION: Duration of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) shedding is important for infection control. The presence of SARS-CoV-2 subgenomic RNA (sgRNA) leader indicates that the virus is replicative. This study examined the shedding duration of SARS-CoV-2 sgRNA leader and genomic RNA (gRNA) in diverse respiratory specimens. METHODOLOGY: One hundred and eleven respiratory specimens collected sequentially from 10 COVID-19 patients with real-time RT-PCR SARS-CoV-2 orf1ab gene confirmed positive admitted to King Chulalongkorn Memorial Hospital were examined for SARS-CoV-2 E sgRNA leader and E gRNA by using Real-time reverse transcription PCR (qRT-PCR). These specimens included nasopharyngeal swab and throat swabs, nasal swab and throat swabs, sputum, and endotracheal aspirate, and were collected from the first day of admission until the time of orf1ab real-time RT-PCR negative of at least 2-4 consecutive days. RESULTS: E sgRNA leader could only be detectable in specimens with ≥ 1E+05 virus E gene copies per ml within the first 15 days after hospitalization. SARS-CoV-2 sgRNA leader was undetectable from one to 15 days earlier than that of gRNA in all patients. Re-shedding of sgRNA was evident in 2 cases, both on a single occasion after being undetectable for 3-10 days. CONCLUSIONS: Assessment of the presence of sgRNA leader may be useful for therapeutic planning.

Dynamics of Neutralizing Antibody and T-Cell Responses to SARS-CoV-2 and Variants of Concern after Primary Immunization with CoronaVac and Booster with BNT162b2 or ChAdOx1 in Health Care Workers.

Inactivated SARS-CoV-2 vaccine (CoronaVac) is commonly used in national immunization programs. However, the immune response significantly declines within a few months. Our study assessed the immune response against SARS-CoV-2 after receiving booster shots of BNT162b2 or ChAdOx1 among health care workers who previously received CoronaVac as their primary immunization. Fifty-six participants who received ChAdOx1 and forty-two participants who received BNT162b2 were enrolled into this study, which evaluated immune responses, including anti-SARS-CoV-2 spike total antibodies (Elecsys®), surrogated viral neutralization test (sVNT) to ancestral strain (cPass™; GenScript), five variants of concern (Alpha, Beta, Gamma, Delta, and Omicron) (Luminex; multiplex sVNT) and the ELISpot with spike (S1 and S2) peptide pool against the ancestral SARS-CoV-2 strain. The samples were analyzed at baseline, 4, and 12 weeks after primary immunization, as well as 4 and 12 weeks after receiving the booster. This study showed a significant increase in anti-SARS-CoV-2 spike total antibodies, sVNT, and T-cell immune response after the booster, including against the Omicron variant. Immune responses rapidly decreased in the booster group at 12 weeks after booster but were still higher than post-primary vaccination. A fourth dose or a second booster should be recommended, particularly in health care workers.

Behavioral-biological surveillance of emerging infectious diseases among a dynamic cohort in Thailand.

BACKGROUND: Interactions between humans and animals are the key elements of zoonotic spillover leading to zoonotic disease emergence. Research to understand the high-risk behaviors associated with disease transmission at the human-animal interface is limited, and few consider regional and local contexts. OBJECTIVE: This study employed an integrated behavioral-biological surveillance approach for the early detection of novel and known zoonotic viruses in potentially high-risk populations, in an effort to identify risk factors for spillover and to determine potential foci for risk-mitigation measures. METHOD: Participants were enrolled at two community-based sites (n = 472) in eastern and western Thailand and two hospital (clinical) sites (n = 206) in northeastern and central Thailand. A behavioral questionnaire was administered to understand participants' demographics, living conditions, health history, and animal-contact behaviors and attitudes. Biological specimens were tested for coronaviruses, filoviruses, flaviviruses, influenza viruses, and paramyxoviruses using pan (consensus) RNA Virus assays. RESULTS: Overall 61/678 (9%) of participants tested positive for the viral families screened which included influenza viruses (75%), paramyxoviruses (15%), human coronaviruses (3%), flaviviruses (3%), and enteroviruses (3%). The most salient predictors of reporting unusual symptoms (i.e., any illness or sickness that is not known or recognized in the community or diagnosed by medical providers) in the past year were having other household members who had unusual symptoms and being scratched or bitten by animals in the same year. Many participants reported raising and handling poultry (10.3% and 24.2%), swine (2%, 14.6%), and cattle (4.9%, 7.8%) and several participants also reported eating raw or undercooked meat of these animals (2.2%, 5.5%, 10.3% respectively). Twenty four participants (3.5%) reported handling bats or having bats in the house roof. Gender, age, and livelihood activities were shown to be significantly associated with participants' interactions with animals. Participants' knowledge of risks influenced their health-seeking behavior. CONCLUSION: The results suggest that there is a high level of interaction between humans, livestock, and wild animals in communities at sites we investigated in Thailand. This study highlights important differences among demographic and occupational risk factors as they relate to animal contact and zoonotic disease risk, which can be used by policymakers and local public health programs to build more effective surveillance strategies and behavior-focused interventions.

Differential escape of neutralizing antibodies by SARS-CoV-2 Omicron and pre-emergent sarbecoviruses.

The SARS-CoV-2 B.1.1.529 lineage, Omicron variant, was first detected in November 2021 and carries 32 amino acid mutations in the spike protein (15 in RBD) and exhibits significant escape of neutralizing antibodies targeting the parental SARS-CoV-2 virus. Here, we performed a high-resolution multiplex (16-plex) surrogate virus neutralization assay covering all major SARS-CoV-2 variants and pre-emergent ACE2-binding sarbecoviruses against 20 different human serum panels from infected, vaccinated and hybrid immune individuals which had vaccine-breakthrough infections or infection followed by vaccination. Among all sarbecoviruses tested, we observed 1.1 to 4.7-, 2.3 to 10.3- and 0.7 to 33.3-fold reduction in neutralization activities to SARS-CoV-2 Beta, Omicron and SARS-CoV-1, respectively. Among the SARS-CoV-2 related sarbecoviruses, it is found that the genetically more distant bat RaTG13 and pangolin GX-P5L sarbecoviruses had less neutralization escape than Omicron. Our data suggest that the SARS-CoV-2 variants emerged from the changed immune landscape of human populations are more potent in escaping neutralizing antibodies, from infection or vaccination, than pre-emergent sarbecoviruses naturally evolved in animal populations with no or less immune selection pressure.

Host genetic factors of COVID-19 susceptibility and disease severity in a Thai population.

Host genetic factors have been shown to play a role in SARs-CoV-2 infection in diverse populations. However, the genetic landscape differs among various ethnicities; therefore, we explored the host genetic factors associated with COVID-19 disease susceptivity and disease severity in a Thai population. We recruited and genotyped 212 unrelated COVID-19 Thai patients and 36 controls using AxiomTM Human Genotyping SARs-COV-2 array, including 847,384 single nucleotide polymorphisms related to SARs-COV-2 pathogenesis, immune response, and related comorbidity No SNPs passed the genome-wide significance threshold of p value <1 × 10-8. However, with a threshold of p value <1 × 10-5, a locus on chromosome 5q32 was found to have a suggestive association with COVID-19 disease susceptibility (p value 6.9 × 10-6; Q-Q plot λ = 0.805, odds ratio 0.02). Notably, IL17B is a gene located in this linkage disequilibrium block and is previously shown to play a part in inflammation and pneumonia. Additionally, a suggestive locus on chromosome 12q22, harboring EEA1 and LOC643339, was associated with COVID-19 disease severity (p value 1.3 × 10-6 - 4.4 × 10-6, Q-Q plot λ = 0.997, odds ratio 0.28-0.31). EEA1 is involved in viral entry into cells, while LOC643339 is a long non-coding RNA. In summary, our study suggested loci on chromosomes 5q32 and 12q22 to be linked to COVID-19 disease susceptibility and disease severity, respectively. The small sample size of this study may lessen the likelihood that the association found is real, but it could still be true. Further study with a larger cohort is required to confirm these findings.