Impact of COVID-19 Vaccination on Pregnant Women.

In light of the COVID-19 pandemic, researchers across the world hastened to develop vaccines that would aid in bolstering herd immunity. Utilizing mRNA coding and viral vector technology, the currently approved vaccines were required to undergo extensive testing to confirm their safety for mass usage in the general population. However, clinical trials failed to test the safety and efficacy of the COVID-19 vaccines in groups with weakened immune systems, especially pregnant women. Lack of information on the effects of vaccinations in pregnancy and the safety of fetuses are among the topmost reasons preventing pregnant women from receiving immunization. Thus, the lack of data examining the effects of COVID-19 vaccinations on pregnant women must be addressed. This review focused on the safety and efficacy of the approved COVID-19 vaccinations in pregnancy and their impact on both maternal and fetal immune responses. For that, we took the approach of combined systematic review/meta-analysis and compiled the available data from the original literature from PubMed, Web of Science, EMBASE and Medline databases. All articles analyzed presented no adverse effects of vaccination in pregnancy, with varying conclusions on the degree of effectiveness. The majority of the findings described robust immune responses in vaccinated pregnant women, successful transplacental antibody transfer, and implications for neonatal immunity. Hence, findings from the cumulative data available can be helpful in achieving COVID-19 herd immunization, including pregnant women.

Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome-An Extempore Game of Misfiring with Defense Arsenals.

The lethal combination involving TB and HIV, known as "syndemic" diseases, synergistically act upon one another to magnify the disease burden. Individuals on anti-retroviral therapy (ART) are at risk of developing TB-associated immune reconstitution inflammatory syndrome (TB-IRIS). The underlying inflammatory complication includes the rapid restoration of immune responses following ART, eventually leading to exaggerated inflammatory responses to MTB antigens. TB-IRIS continues to be a cause of morbidity and mortality among HIV/TB coinfected patients initiating ART, and although a significant quantum of knowledge has been acquired on the pathogenesis of IRIS, the underlying pathomechanisms and identification of a sensitive and specific diagnostic marker still remain a grey area of investigation. Here, we reviewed the latest research developments into IRIS immunopathogenesis, and outlined the modalities to prevent and manage strategies for better clinical and diagnostic outcomes for IRIS.

T cell perturbations persist for at least 6 months following hospitalization for COVID-19.

COVID-19 is being extensively studied, and much remains unknown regarding the long-term consequences of the disease on immune cells. The different arms of the immune system are interlinked, with humoral responses and the production of high-affinity antibodies being largely dependent on T cell immunity. Here, we longitudinally explored the effect COVID-19 has on T cell populations and the virus-specific T cells, as well as neutralizing antibody responses, for 6-7 months following hospitalization. The CD8+ TEMRA and exhausted CD57+ CD8+ T cells were markedly affected with elevated levels that lasted long into convalescence. Further, markers associated with T cell activation were upregulated at inclusion, and in the case of CD69+ CD4+ T cells this lasted all through the study duration. The levels of T cells expressing negative immune checkpoint molecules were increased in COVID-19 patients and sustained for a prolonged duration following recovery. Within 2-3 weeks after symptom onset, all COVID-19 patients developed anti-nucleocapsid IgG and spike-neutralizing IgG as well as SARS-CoV-2-specific T cell responses. In addition, we found alterations in follicular T helper (TFH) cell populations, such as enhanced TFH-TH2 following recovery from COVID-19. Our study revealed significant and long-term alterations in T cell populations and key events associated with COVID-19 pathogenesis.

Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and Omicron BA.1.1.529 but not with Omicron BA.1.1 and BA.2 variants.

The rapid spread of SARS-CoV-2 variants in the global population is indicative of the development of selective advantages in emerging virus strains. Here, we performed a case-control investigation of the clinical and demographic characteristics, clinical history, and virological markers to predict disease progression in hospitalized adults for COVID-19 between December 2021 and January 2022 in Chennai, India. COVID-19 diagnosis was made by a commercial TaqPath COVID-19 RT-PCR, and WGS was performed with the Ion Torrent Next Generation Sequencing System. High-quality (<5% of N) complete sequences of 73 Omicron B.1.1.529 variants were randomly selected for phylogenetic analysis. SARS-CoV-2 viral load, number of comorbidities, and severe disease presentation were independently associated with a shorter time-to-death. Strikingly, this was observed among individuals infected with Omicron BA.2 but not among those with the BA.1.1.529, BA.1.1, or the Delta B.1.617.2 variants. Phylogenetic analysis revealed severe cases predominantly clustering under the BA.2 lineage. Sequence analyses showed 30 mutation sites in BA.1.1.529 and 33 in BA.1.1. The mutations unique to BA.2 were T19I, L24S, P25del, P26del, A27S, V213G, T376A, D405N and R408S. Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and the Omicron BA.1.1.529 variant but not with Omicron BA.1.1 or BA.2 suggests that the newer strains are largely immune escape variants. The number of vaccine doses received was independently associated with increased odds of developing asymptomatic disease or recovery. We propose that the novel mutations reported herein could likely bear a significant impact on the clinical characteristics, disease progression, and epidemiological aspects of COVID-19. Surging rates of mutations and the emergence of eclectic variants of SARS-CoV-2 appear to impact disease dynamics.

Factors Associated With the Decay of Anti-SARS-CoV-2 S1 IgG Antibodies Among Recipients of an Adenoviral Vector-Based AZD1222 and a Whole-Virion Inactivated BBV152 Vaccine.

Background: The magnitude of protection conferred following recovery from COVID-19 or by vaccine administration, and the duration of protective immunity developed, remains ambiguous. Methods: We investigated the factors associated with anti-SARS-CoV-2 S1 IgG decay in 519 individuals who recovered from COVID-19 illness or received COVID-19 vaccination with two commercial vaccines, viz., an adenoviral vector-based (AZD1222) and a whole-virion-based inactivated (BBV152) vaccine in Chennai, India from March to December 2021. Blood samples collected during regular follow-up post-infection/-vaccination were examined for anti-SARS-CoV-2 S1 IgG by a commercial automated chemiluminescent immunoassay (CLIA). Results: Age and underlying comorbidities were the two variables that were independently associated with the development of a breakthrough infection. Individuals who were >60 years of age with underlying comorbid conditions (viz., hypertension, diabetes mellitus and cardiovascular disease) had a ~15 times and ~10 times greater odds for developing a breakthrough infection and hospitalization, respectively. The time elapsed since the first booster dose was associated with attrition in anti-SARS-CoV-2 IgG, where each month passed was associated with an ebb in the anti-SARS-CoV-2 IgG antibody levels by a coefficient of -6 units. Conclusions: Our findings advocate that the elderly with underlying comorbidities be administered with appropriate number of booster doses with AZD1222 and BBV152 against COVID-19.

Japan prospective multicenter study for optimization of COVID-19 vaccinations based on the immune response and safety profile in Inflammatory Bowel Disease patients: Interim analyses of the J-COMBAT trial

Background Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Methods IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and non-administrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti-TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1–62.3;p=0.0293), and tended to be influenced by COVID-19 infection (139.1, 41.0–472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA-1273 (90.3 [60.8–134.1]) than for BNT162b2 (39.6 [35.2–44.6], p= 0.0001). Systemic steroids (22.9 [13.9–37.7], p=0.0119), IM (24.2 [18.7–31.4], p<0.0001), anti-TNF agents (20.8 [15.3–28.3], p<0.0001), vedolizumab (25.2 [15.0–42.2], p=0.0409), ustekinumab (28.9 [18.5–45.0], p=0.0754), and tofacitinib (5.5 [2.8–10.9], p<0.0001), but not oral 5-ASA (39.1 [31.9–47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs.

T cell perturbations persist for at least 6 months following hospitalization for COVID-19

COVID-19 is being extensively studied, and much remains unknown regarding the long-term consequences of the disease on immune cells. The different arms of the immune system are interlinked, with humoral responses and the production of high-affinity antibodies being largely dependent on T cell immunity. Here, we longitudinally explored the effect COVID-19 has on T cell populations and the virus-specific T cells, as well as neutralizing antibody responses, for 6-7 months following hospitalization. The CD8+ TEMRA and exhausted CD57+ CD8+ T cells were markedly affected with elevated levels that lasted long into convalescence. Further, markers associated with T cell activation were upregulated at inclusion, and in the case of CD69+ CD4+ T cells this lasted all through the study duration. The levels of T cells expressing negative immune checkpoint molecules were increased in COVID-19 patients and sustained for a prolonged duration following recovery. Within 2-3 weeks after symptom onset, all COVID-19 patients developed anti-nucleocapsid IgG and spike-neutralizing IgG as well as SARS-CoV-2-specific T cell responses. In addition, we found alterations in follicular T helper (TFH) cell populations, such as enhanced TFH-TH2 following recovery from COVID-19. Our study revealed significant and long-term alterations in T cell populations and key events associated with COVID-19 pathogenesis.

JAPAN PROSPECTIVE MULTICENTER STUDY FOR OPTIMIZATION OF COVID-19 VACCINATIONS BASED ON THE IMMUNE RESPONSE AND SAFETY PROFILE IN INFLAMMATORY BOWEL DISEASE PATIENTS: INTERIM ANALYSES

Background: Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Subjects and Methods: IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results: In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and non-administrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti- TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1-62.3;p=0.0293), and tended to be influenced by COVID- 19 infection (139.1, 41.0-472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA- 1273 (90.3 [60.8-134.1]) than for BNT162b2 (39.6 [35.2-44.6], p= 0.0001). Systemic steroids (22.9 [13.9-37.7], p=0.0119), IM (24.2 [18.7-31.4], p<0.0001), anti-TNF agents (20.8 [15.3-28.3], p<0.0001), vedolizumab (25.2 [15.0-42.2], p=0.0409), ustekinumab (28.9 [18.5-45.0], p=0.0754), and tofacitinib (5.5 [2.8-10.9], p<0.0001), but not oral 5- ASA (39.1 [31.9-47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion: Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs. (Table Presented) (Table Presented)

Dengue Infection - Recent Advances in Disease Pathogenesis in the Era of COVID-19.

The dynamics of host-virus interactions, and impairment of the host's immune surveillance by dengue virus (DENV) serotypes largely remain ambiguous. Several experimental and preclinical studies have demonstrated how the virus brings about severe disease by activating immune cells and other key elements of the inflammatory cascade. Plasmablasts are activated during primary and secondary infections, and play a determinative role in severe dengue. The cross-reactivity of DENV immune responses with other flaviviruses can have implications both for cross-protection and severity of disease. The consequences of a cross-reactivity between DENV and anti-SARS-CoV-2 responses are highly relevant in endemic areas. Here, we review the latest progress in the understanding of dengue immunopathogenesis and provide suggestions to the development of target strategies against dengue.

Japan prospective multicenter study for optimization of COVID-19 vaccinations based on the immune response and safety profile in Inflammatory Bowel Disease patients: Interim analyses of the J-COMBAT trial

Background: Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Methods: IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results: In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and nonadministrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti-TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1-62.3;p=0.0293), and tended to be influenced by COVID-19 infection (139.1, 41.0-472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA-1273 (90.3 [60.8-134.1]) than for BNT162b2 (39.6 [35.2-44.6], p= 0.0001). Systemic steroids (22.9 [13.9-37.7], p=0.0119), IM (24.2 [18.7-31.4], p<0.0001), anti-TNF agents (20.8 [15.3-28.3], p<0.0001), vedolizumab (25.2 [15.0-42.2], p=0.0409), ustekinumab (28.9 [18.5-45.0], p=0.0754), and tofacitinib (5.5 [2.8-10.9], p<0.0001), but not oral 5-ASA (39.1 [31.9-47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion: Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs.

Hijacking of the Host's Immune Surveillance Radars by Burkholderia pseudomallei.

Burkholderia pseudomallei (B. pseudomallei) causes melioidosis, a potentially fatal disease for which no licensed vaccine is available thus far. The host-pathogen interactions in B. pseudomallei infection largely remain the tip of the iceberg. The pathological manifestations are protean ranging from acute to chronic involving one or more visceral organs leading to septic shock, especially in individuals with underlying conditions similar to COVID-19. Pathogenesis is attributed to the intracellular ability of the bacterium to 'step into' the host cell's cytoplasm from the endocytotic vacuole, where it appears to polymerize actin filaments to spread across cells in the closer vicinity. B. pseudomallei effectively evades the host's surveillance armory to remain latent for prolonged duration also causing relapses despite antimicrobial therapy. Therefore, eradication of intracellular B. pseudomallei is highly dependent on robust cellular immune responses. However, it remains ambiguous why certain individuals in endemic areas experience asymptomatic seroconversion, whereas others succumb to sepsis-associated sequelae. Here, we propose key insights on how the host's surveillance radars get commandeered by B. pseudomallei.

SARS-CoV-2-Indigenous Microbiota Nexus: Does Gut Microbiota Contribute to Inflammation and Disease Severity in COVID-19?

Gut microbiome alterations may play a paramount role in determining the clinical outcome of clinical COVID-19 with underlying comorbid conditions like T2D, cardiovascular disorders, obesity, etc. Research is warranted to manipulate the profile of gut microbiota in COVID-19 by employing combinatorial approaches such as the use of prebiotics, probiotics and symbiotics. Prediction of gut microbiome alterations in SARS-CoV-2 infection may likely permit the development of effective therapeutic strategies. Novel and targeted interventions by manipulating gut microbiota indeed represent a promising therapeutic approach against COVID-19 immunopathogenesis and associated co-morbidities. The impact of SARS-CoV-2 on host innate immune responses associated with gut microbiome profiling is likely to contribute to the development of key strategies for application and has seldom been attempted, especially in the context of symptomatic as well as asymptomatic COVID-19 disease.

Asymptomatic SARS-CoV-2 infection: is it all about being refractile to innate immune sensing of viral spare-parts?-Clues from exotic animal reservoirs.

A vast proportion of coronavirus disease 2019 (COVID-19) individuals remain asymptomatic and can shed severe acute respiratory syndrome (SARS-CoV) type 2 virus to transmit the infection, which also explains the exponential increase in the number of COVID-19 cases globally. Furthermore, the rate of recovery from clinical COVID-19 in certain pockets of the globe is surprisingly high. Based on published reports and available literature, here, we speculated a few immunovirological mechanisms as to why a vast majority of individuals remain asymptomatic similar to exotic animal (bats and pangolins) reservoirs that remain refractile to disease development despite carrying a huge load of diverse insidious viral species, and whether such evolutionary advantage would unveil therapeutic strategies against COVID-19 infection in humans. Understanding the unique mechanisms that exotic animal species employ to achieve viral control, as well as inflammatory regulation, appears to hold key clues to the development of therapeutic versatility against COVID-19.