Analysis of Clinical Outcomes of Pregnant Patients Treated With Nirmatrelvir and Ritonavir for Acute SARS-CoV-2 Infection

IMPORTANCE

Pregnant people are at increased risk of poor outcomes due to infection with SARS-CoV-2, and there are limited therapeutic options available.

OBJECTIVE

To evaluate the clinical outcomes associated with nirmatrelvir and ritonavir used to treat SARS-CoV-2 infection in pregnant patients.

DESIGN, SETTING, AND PARTICIPANTS

This case series included pregnant patients who were diagnosed with SARS-CoV-2 infection, received nirmatrelvir and ritonavir, and delivered their offspring within the Johns Hopkins Health System between December 22, 2021, and August 20, 2022.

EXPOSURES

Treatment with nirmatrelvir and ritonavir for SARS-CoV-2 infection during pregnancy.

MAIN OUTCOMES AND MEASURES

Clinical characteristics and outcomes were ascertained through manual record review.

RESULTS

Forty-seven pregnant patients (median [range] age, 34 [22-43] years) were included in the study, and the median (range) gestational age of their offspring was 28.4 (4.3-39.6) weeks. Medication was initiated at a median (range) of 1 (0-5) day after symptom onset, and only 2 patients [4.3%] did not complete the course of therapy because of adverse effects. Thirty patients (63.8%) treated with nirmatrelvir and ritonavir had a comorbidity in addition to pregnancy that could be a risk factor for developing severe COVID-19. Twenty-five patients [53.2%] delivered after treatment with nirmatrelvir and ritonavir. Twelve of these patients [48.0%] underwent cesarean delivery, 9 [75.0%] of which were scheduled. Two of 47 patients [4.3%] were hospitalized for conditions related to preexisting comorbidities.

CONCLUSIONS AND RELEVANCE

In this case series, pregnant patients who were treated with nirmatrelvir and ritonavir tolerated treatment well, although there was an unexpectedly high rate of cesarean deliveries. The lack of an increase in serious adverse effects affecting pregnant patients or offspring suggests that clinicians can use this drug combination to treat pregnant patients with SARS-CoV-2 infection.

The immune phenotype of perinatal anxiety

BACKGROUND

Immune dysregulation has been linked to both psychiatric illness and pregnancy morbidity, including perinatal depression, but little is known about the immune phenotype of perinatal anxiety. Here, we sought to identify the unique immune profile of antenatal anxiety.

MATERIALS AND METHODS

Pregnant women (n = 107) were followed prospectively at 2nd and 3rd trimesters (T2, T3) and 6 weeks postpartum (PP6). Each visit included a blood draw and psychological evaluation, with clinical anxiety assessed using the Spielberg State-Trait Anxiety Scale. We enrolled both healthy controls and participants with anxiety alone; those with comorbid depression were excluded. Multiplex cytokine assays and flow cytometry were used to examine the association of anxiety symptoms with secreted immune markers and PBMC-derived immune cells.

RESULTS

K cluster means revealed three clusters of anxiety symptomatology; due to low numbers in the highest severity anxiety group, these were collapsed into two groups: Non-Anxiety and Anxiety. Principal components analysis revealed two distinct clusters of cytokine secretion including one cluster that consisted of many innate immune cytokines and differed between groups. Compared to women in the Non-Anxiety group, women in the Anxiety group had lower levels of cytokine expression during pregnancy and an increase in levels into the postpartum, whereas Non-Anxiety women experienced a time-dependent decline. Immune cell populations also differed between our two groups, with the Anxiety group showing a decrease in the ratio of B cells to T cells from pregnancy to postpartum, whereas the Non-Anxiety women showed an increase in this ratio over time. Women in the Anxiety group also demonstrated an increased ratio of cytotoxic to helper T cells throughout pregnancy, a modest increase in the Th1:Th2 ratio across pregnancy, and a lower ratio of Th17:T_REG cells in the postpartum as compared with Non-Anxiety women.

CONCLUSION

These data suggest that the immune response throughout the antenatal period differs for women with anxiety symptoms compared to those without, suggestive of a unique immune phenotype of perinatal anxiety.

Greater Breadth of Vaccine-Induced Immunity in Females than Males Is Mediated by Increased Antibody Diversity in Germinal Center B Cells

Inactivated influenza vaccines induce greater antibody responses in females than males among both humans and mice. To test the breadth of protection, we used recombinant mouse-adapted A/California/2009 (maA/Cal/09) H1N1 viruses containing mutations at one (1M), two (2M), or three (3M) antigenic sites, in addition to a virus containing the 1M mutation and a substitution of the Ca2 antigenic site (Sub) with one derived from an H5 hemagglutinin (HA) to challenge mice of both sexes. Following maA/Cal/09 vaccination, females produced greater virus-specific, class-switched total IgG and IgG2c antibodies against the vaccine and all mutant viruses, and antibodies from females recognized a greater number of unique, linear HA epitopes than did antibodies from males. While females had greater neutralizing antibody titers against the vaccine virus, both sexes showed a lower neutralization capacity against mutant viruses. After virus challenge, vaccinated females had lower pulmonary virus titers and reduced morbidity than males for the 1M and 2M viruses, but not the Sub virus. Females generated greater numbers of germinal center (GC) B cells containing superior somatic hypermutation (SHM) frequencies than vaccinated males. Deletion of activation-induced cytidine deaminase (Aicda) eliminated female-biased immunity and protection against the 2M virus. Harnessing methods to improve GC B cell responses and frequencies of SHM, especially in males, should be considered in the development of universal influenza vaccines. IMPORTANCE Adult females develop greater antibody responses to influenza vaccines than males. We hypothesized that female-biased immunity and protection would be dependent on the extent of virus diversity as well as molecular mechanisms in B cells which constrain the breadth of epitope recognition. We developed a panel of mouse-adapted (ma) A/Cal/09 viruses that had mutations in the immunodominant hemagglutinin. Following vaccination against maA/Cal/09, females were better able to neutralize maA/Cal/09 than males, but neutralization of mutant maA/Cal/09 viruses was equally poor in both sexes, despite vaccinated females being better protected against these viruses. Vaccinated females benefited from the greater production of class-switched, somatically hypermutated antibodies generated in germinal center B cells, which increased recognition of more diverse maA/Cal/09 hemagglutinin antigen epitopes. Female-biased protection against influenza infection and disease after vaccination is driven by differential mechanisms in males versus females and should be considered in the design of novel vaccine platforms.

Sex Differences in Active Pulmonary Tuberculosis Outcomes in Mali, West Africa

Men and women often respond differently to infectious diseases and their treatments. Tuberculosis (TB) is a life-threatening communicable disease that affects more men than women globally. Whether male sex is an independent risk factor for unfavorable TB outcomes, however, has not been rigorously investigated in an African context, where individuals are likely exposed to different microbial and environmental factors. We analyzed data collected from a cohort study in Mali by focusing on newly diagnosed active pulmonary TB individuals who were treatment naive. We gathered baseline demographic, clinical, and microbiologic characteristics before treatment initiation and also at three time points during treatment. More males than females were affected with TB, as evidenced by a male-to-female ratio of 2.4:1. In addition, at baseline, males had a significantly higher bacterial count and shorter time to culture positivity as compared with females. Male sex was associated with lower smear negativity rate after 2 months of treatment also known as the intensive phase of treatment, but not at later time points. There was no relationship between patients' sex and mortality from any cause during treatment. This study suggests that sex-based differences in TB outcomes exist, with sex-specific effects on disease outcomes being more pronounced before treatment initiation and during the intensive phase of treatment rather than at later phases of treatment.

Association of Frailty, Age, and Biological Sex With Severe Acute Respiratory Syndrome Coronavirus 2 Messenger RNA Vaccine-Induced Immunity in Older Adults

BACKGROUND

Male sex and old age are risk factors for severe coronavirus disease 2019, but the intersection of sex and aging on antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines has not been characterized.

METHODS

Plasma samples were collected from older adults (aged 75-98 years) before and after 3 doses of SARS-CoV-2 mRNA vaccination, and from younger adults (aged 18-74 years) post-dose 2, for comparison. Antibody binding to SARS-CoV-2 antigens (spike protein [S], S receptor-binding domain, and nucleocapsid), functional activity against S, and live-virus neutralization were measured against the vaccine virus and the Alpha, Delta, and Omicron variants of concern (VOCs).

RESULTS

Vaccination induced greater antibody titers in older females than in older males, with both age and frailty associated with reduced antibody responses in males but not females. Responses declined significantly in the 6 months after the second dose. The third dose restored functional antibody responses and eliminated disparities caused by sex, age, and frailty in older adults. Responses to the VOCs, particularly the Omicron variant, were significantly reduced relative to the vaccine virus, with older males having lower titers to the VOCs than older females. Older adults had lower responses to the vaccine and VOC viruses than younger adults, with greater disparities in males than in females.

CONCLUSIONS

Older and frail males may be more vulnerable to breakthrough infections owing to low antibody responses before receipt of a third vaccine dose. Promoting third dose coverage in older adults, especially males, is crucial to protecting this vulnerable population.

A Fourth Dose of COVID-19 Vaccine Does Not Induce Neutralization of the Omicron Variant Among Solid Organ Transplant Recipients With Suboptimal Vaccine Response

BACKGROUND

Humoral responses to coronavirus disease 2019 (COVID-19) vaccines are attenuated in solid organ transplant recipients (SOTRs), necessitating additional booster vaccinations. The Omicron variant demonstrates substantial immune evasion, and it is unknown whether additional vaccine doses increase neutralizing capacity versus this variant of concern (VOC) among SOTRs.

METHODS

Within an observational cohort, 25 SOTRs with low seroresponse underwent anti-severe acute respiratory syndrome coronavirus 2 spike and receptor-binding domain immunoglobulin (Ig)G testing using a commercially available multiplex ELISA before and after a fourth COVID-19 vaccine dose (D4). Surrogate neutralization (percent angiotensin-converting enzyme 2 inhibition [%ACE2i], range 0%-100% with >20% correlating with live virus neutralization) was measured against full-length spike proteins of the vaccine strain and 5 VOCs including Delta and Omicron. Changes in IgG level and %ACE2i were compared using the paired Wilcoxon signed-rank test.

RESULTS

Anti-receptor-binding domain and anti-spike seropositivity increased post-D4 from 56% to 84% and 68% to 88%, respectively. Median (interquartile range) anti-spike antibody significantly increased post-D4 from 42.3 (4.9-134.2) to 228.9 (1115.4-655.8) World Health Organization binding antibody units. %ACE2i (median [interquartile range]) also significantly increased against the vaccine strain (5.8% [0%-16.8%] to 20.6% [5.8%-45.9%]) and the Delta variant (9.1% [4.9%-12.8%] to 17.1% [10.3%-31.7%]), yet neutralization versus Omicron was poor, did not increase post-D4 (4.1% [0%-6.9%] to 0.5% [0%-5.7%]), and was significantly lower than boosted healthy controls.

CONCLUSIONS

Although a fourth vaccine dose increases anti-spike IgG and neutralizing capacity against many VOCs, some SOTRs may remain at high risk for Omicron infection despite boosting. Thus, additional protective interventions or alternative vaccination strategies should be urgently explored.

Genetic and hormonal mechanisms underlying sex-specific immune responses in tuberculosis

Tuberculosis (TB), the world's deadliest bacterial infection, afflicts more human males than females, with a male/female (M/F) ratio of 1.7. Sex disparities in TB prevalence, pathophysiology, and clinical manifestations are widely reported, but the underlying biological mechanisms remain largely undefined. This review assesses epidemiological data on sex disparity in TB, as well as possible underlying hormonal and genetic mechanisms that might differentially modulate innate and adaptive immune responses in males and females, leading to sex differences in disease susceptibility. We consider whether this sex disparity can be extended to the efficacy of vaccines and discuss novel animal models which may offer mechanistic insights. A better understanding of the biological factors underpinning sex-related immune responses in TB may enable sex-specific personalized therapies for TB.

My story of sex, gender, and women's health in a pandemic

After more than 20 years of studying sex differences in viral pathogenesis and immunity to vaccines, the COVID‐19 pandemic provided me with a unique opportunity to raise awareness about biological sex differences. The scientific community and public, alike, embraced the clinical and epidemiological data and supported inquiries into how males are twice as likely to be hospitalized and die from COVID‐19. Immunological changes associated with pregnancy also contribute to worse outcomes from COVID‐19. Collectively, we are finding that inflammation is a critical mediator of worse outcomes for males and pregnant females. The pandemic gave me a platform to discuss and address sex differences on a bigger stage, but two decades of studies working with other viruses prepared me for this moment in history.

Sex biases in infectious diseases research

Reporting the distribution and inclusion of both males and females in immunology and infectious diseases research is improving, but rigorous analyses of differential outcomes between males and females, including mechanistic inquiries into the causes of sex differences, still lags behind.

Mission, Organization, and Future Direction of the Serological Sciences Network for COVID-19 (SeroNet) Epidemiologic Cohort Studies

Background

Global efforts are needed to elucidate the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the underlying cause of coronavirus disease 2019 (COVID-19), including seroprevalence, risk factors, and long-term sequelae, as well as immune responses after vaccination across populations and the social dimensions of prevention and treatment strategies.

Methods

In the United States, the National Cancer Institute in partnership with the National Institute of Allergy and Infectious Diseases, established the SARS-CoV-2 Serological Sciences Network (SeroNet) as the nation's largest coordinated effort to study coronavirus disease 2019. The network comprises multidisciplinary researchers bridging gaps and fostering collaborations among immunologists, epidemiologists, virologists, clinicians and clinical laboratories, social and behavioral scientists, policymakers, data scientists, and community members. In total, 49 institutions form the SeroNet consortium to study individuals with cancer, autoimmune disease, inflammatory bowel diseases, cardiovascular diseases, human immunodeficiency virus, transplant recipients, as well as otherwise healthy pregnant women, children, college students, and high-risk occupational workers (including healthcare workers and first responders).

Results

Several studies focus on underrepresented populations, including ethnic minorities and rural communities. To support integrative data analyses across SeroNet studies, efforts are underway to define common data elements for standardized serology measurements, cellular and molecular assays, self-reported data, treatment, and clinical outcomes.

Conclusions

In this paper, we discuss the overarching framework for SeroNet epidemiology studies, critical research questions under investigation, and data accessibility for the worldwide scientific community. Lessons learned will help inform preparedness and responsiveness to future emerging diseases.

Early Outpatient Treatment for Covid-19 with Convalescent Plasma

BACKGROUND

Polyclonal convalescent plasma may be obtained from donors who have recovered from coronavirus disease 2019 (Covid-19). The efficacy of this plasma in preventing serious complications in outpatients with recent-onset Covid-19 is uncertain.

METHODS

In this multicenter, double-blind, randomized, controlled trial, we evaluated the efficacy and safety of Covid-19 convalescent plasma, as compared with control plasma, in symptomatic adults (≥18 years of age) who had tested positive for severe acute respiratory syndrome coronavirus 2, regardless of their risk factors for disease progression or vaccination status. Participants were enrolled within 8 days after symptom onset and received a transfusion within 1 day after randomization. The primary outcome was Covid-19-related hospitalization within 28 days after transfusion.

RESULTS

Participants were enrolled from June 3, 2020, through October 1, 2021. A total of 1225 participants underwent randomization, and 1181 received a transfusion. In the prespecified modified intention-to-treat analysis that included only participants who received a transfusion, the primary outcome occurred in 17 of 592 participants (2.9%) who received convalescent plasma and 37 of 589 participants (6.3%) who received control plasma (absolute risk reduction, 3.4 percentage points; 95% confidence interval, 1.0 to 5.8; P = 0.005), which corresponded to a relative risk reduction of 54%. Evidence of efficacy in vaccinated participants cannot be inferred from these data because 53 of the 54 participants with Covid-19 who were hospitalized were unvaccinated and 1 participant was partially vaccinated. A total of 16 grade 3 or 4 adverse events (7 in the convalescent-plasma group and 9 in the control-plasma group) occurred in participants who were not hospitalized.

CONCLUSIONS

In participants with Covid-19, most of whom were unvaccinated, the administration of convalescent plasma within 9 days after the onset of symptoms reduced the risk of disease progression leading to hospitalization. (Funded by the Department of Defense and others; CSSC-004 ClinicalTrials.gov number, NCT04373460.).

Influenza A virus-specific maternal antibodies impair vaccine-induced antibody responses and protection in male to a greater extent than female offspring

Influenza A virus (IAV) is a public health threat to pregnant people and infants. Transfer of antibodies across the placenta to the fetus and during lactation provides key protection from infectious pathogens during the neonatal period. Despite this, pathogen-specific maternal antibodies may interfere with infant vaccination. We hypothesized that transfer of IAV-specific maternal antibody, would negatively affect vaccine-induced immunity and protection in male and female offspring, with males being more impacted. Pregnant CD1 mice were infected on embryonic day 10 with 103TCID50 of mouse adapted A/California/09 H1N1 (ma2009 H1N1) or mock inoculated. In offspring of IAV-infected dams, maternal anti-ma2009 H1N1 IgG peaked at 3-weeks, declined at 7-weeks, and undetectable at 15-weeks of age. At 3-, 7-, and 15-weeks, male and female offspring were intramuscularly vaccinated with inactivated ma2009 H1N1 vaccine, boosted 21 days later, and had serum collected 14 days post-boost. Following vaccination, 3-week-old offspring of IAV-infected dams displayed significantly lower vaccine-induced anti-ma2009 H1N1 IgG titers compared to offspring born from mock-infected dams. At 7 weeks of age, vaccine-induced IgG titers were significantly inhibited in male but not female offspring. In 15-week-old offspring of IAV-infected dams, vaccine-induced antibody responses were similar to offspring of mock-infected dams, being greater in female than male offspring. These data suggest that IAV-specific maternal antibodies negatively impact the offspring response to IAV-vaccination, with this more pronounced in males than females. This research is important for understanding the factors that impact vaccine-induced immunity in early life.

Supported by funding from the Johns Hopkins Vivien Thomas Scholars Initiative and grants from NIH/NICHD R01 HD097608, JH-CEIRS contract HHSN272201400007C, and NIH/NIA U54AG062333, NIH/NIAD 2T32A1007417-26

Alternative lineage B cells utilizing fatty acid oxidation predict response to third dose COVID vaccination in solid organ transplant recipients

Solid organ transplant recipients (SOTRs) demonstrate reduced seroconversion and increased breakthrough infection rates following standard two dose mRNA vaccination against SARs-CoV-2. However, within a prospective cohort of SOTRs, the majority of patients (72%) developed a positive anti-Spike (S) IgG following a third vaccine dose, compared to only 15% following two doses. Those who failed to respond to vaccination uniformly received mycophenolate mofetil (MMF). To better understand mechanisms underlying divergent vaccine responses, both global and S-specific B cells were evaluated using flow cytometry to assess immunologic and metabolic phenotypes. Prior to the third dose, 76% of SOTRs demonstrated detectable S-specific B cells even though only 15% had positive anti-S IgG titers. However, B cells were skewed towards a non-class switched phenotype in SOTRs compared to healthy controls. Response to a third dose was predicted by expanded populations of germinal center (GC)-like B cells and CD11c+ alternative lineage B cells with upregulation of carnitine palmitoyltransferase 1a (CPT1a), the rate limiting enzyme for fatty acid oxidation (FAO), a preferred energy source of GC B cells. SOTRs receiving high dose MMF demonstrated significantly lower expression of CPT1a compared to healthy controls, indicating an energetic deficit associated with MMF and failure to respond. Further, in vitro treatment of B cells with MMF reduced the ability to oxidize fatty acids and induced an accumulation of intracellular lipid droplets. Together, these data define alternative lineage B cells present in those who respond to a third vaccine dose, outlining FAO as a metabolic pathway that could be targeted to improve vaccine responses.

Estradiol replacement improves vaccine-induced antibody responses and protection against influenza in aged female mice

Adult female mice generate greater vaccine-induced immunity and protection than their male counterparts, but this female advantage is lost with age. We hypothesized that treatment of aged female mice with exogenous estradiol would improve vaccine-induced antibody responses and protection from both pulmonary infection and disease after live influenza virus challenge. To investigate this, adult (2–3 months old) and aged (17–18 months old) female C57BL/6 mice were implanted with either empty (placebo) capsules or capsules loaded with 17β-estradiol (E2) hormone, and then vaccinated with mouse-adapted A/California/04/09 (ma2009 H1N1) vaccine. Total IgG and neutralizing antibody titers (nAb) were quantified using blood samples collected post vaccination. >1 month post vaccination, mice were challenged intranasally with ma2009 H1N1 drift variant virus. A subset of mice was euthanized at 3 days post challenge to collect lungs and measure infectious virus titer. Another subset was followed for 14 days to measure changes in body mass as a measure of disease severity. We found that aged female mice treated with E2 produced significantly greater IgG and nAb responses compared to placebo-treated aged females, and the responses of E2-treated aged females were comparable to the antibody responses generated in adult females. Treatment with E2 also reduced morbidity, but not pulmonary virus titers, following live virus challenge. Our data suggest that estrogen replacement in aged female mice improves their humoral immune response to influenza vaccination and protects them from severe disease.

Supported by U54AG062333

Sex differences in B cell frequencies and antibody responses following influenza vaccination in healthcare workers during the 2019–2020 season

Annual influenza vaccination for healthcare workers (HCWs) is required at Johns Hopkins to reduce influenza spread in healthcare facilities. We conducted a clinical study to evaluate sex differences in virus-specific antibody-producing B cells (i.e., plasmablasts) following receipt of the seasonal influenza vaccine in a highly vaccinated population of healthcare workers. To understand sex differences in immune responses to the influenza vaccine in the HCWs, 83 participants consented to blood draws at baseline and 75 participants returned for the 7- and 28-days post-vaccination survey and blood draw. Participants received their annual quadrivalent influenza vaccine (QIV). Influenza A specific plasmablasts were quantified at baseline and day 7 post-vaccination. Males had a significantly greater percentage of influenza-specific plasmablasts than females after vaccination (p<0.0003) Plasma collected at baseline and at day 28 post-vaccination was used to measure neutralizing antibody (nAb) titers against H1N1 and H3N2 vaccine viruses. Neutralizing antibody responses against either the H1N1 and H3N2 viruses increase after vaccination to the same degree in both males and females. The proportion of plasmablasts at day 7 was significantly associated with the vaccine-induced fold rise in nAb. This relationship differed by sex, whereby for a given proportion of plasmablasts, females tended to mount a greater fold-rise in nAb than males. These data suggest that despite having potentially fewer plasmablasts after vaccination, females mount an antiviral antibody response to the influenza vaccine viruses equivalent to males. Identification of transcriptional differences in plasmablasts from male and female HCWs is ongoing.

Sex hormones more than sex chromosomal complement predict sex differences in influenza vaccine-induced immunity and protection in mice

Following influenza vaccination, adult female mice have greater quantity and quality of antiviral antibodies than males, which is a correlate of protection against live influenza virus challenge. Whether sex steroid hormone concentrations, sex chromosome complement, or both underlie greater immunity and protection following vaccination has not been determined. To dissect the relative contribution of steroid hormones and chromosome complement, we used the Four Core Genotype (FCG) mouse model on a C57BL/6 background to evaluate how gonadal sex (i.e., testes or ovaries) and sex chromosome complement (i.e., XX or XY) can independently or together contribute to sex differences in influenza immunity. Adult FCG mice were vaccinated intramuscularly with inactivated mouse-adapted A/California/04/09 (ma2009 H1N1). Blood samples were collected at several time points post vaccination to measure total IgG and neutralizing antibodies. All mice were challenged intranasally with live ma2009 H1N1 drift variant virus and used to either measure lung virus replication kinetics or disease pathogenesis. Gonadal females (i.e., XXF and XYF), regardless of chromosome complement, produced greater antibody responses and had less pulmonary virus replication than gonadal males (i.e., XYM and XXM). Gonadal sex and sex chromosomal complement intersected to impact disease severity following challenge, in which among gonadal females, XX females experienced less morbidity than XY females. In contrast, there was no effect of chromosome complement among gonadal males. Our data suggests that sex steroid hormones more than sex chromosome complement underlie sex differences in influenza vaccine-induced immunity and protection.

Financial support provided by NIH/OWRH/NIA U54AG062333

Higher Proinflammatory Cytokines Are Associated With Increased Antibody Titer After a Third Dose of SARS-CoV-2 Vaccine in Solid Organ Transplant Recipients

BACKGROUND

Solid organ transplant recipients (SOTRs) are at increased risk for severe COVID-19 and exhibit lower antibody responses to SARS-CoV-2 vaccines. This study aimed to determine if prevaccination cytokine levels are associated with antibody response to SARS-CoV-2 vaccination.

METHODS

A cross-sectional study was performed among 58 SOTRs before and after two-dose mRNA vaccine series, 35 additional SOTRs before and after a third vaccine dose, and comparison to 16 healthy controls (HCs). Antispike antibody was assessed using the IgG Euroimmun ELISA. Electrochemiluminescence detection-based multiplexed sandwich immunoassays (Meso Scale Diagnostics) were used to quantify plasma cytokine and chemokine concentrations (n = 20 analytes) and compare concentrations between SOTRs and HCs, stratified by ultimate antibody response to the vaccine using Wilcoxon-rank-sum test with false discovery rates computed to correct for multiple comparisons.

RESULTS

In the study population, 100% of HCs, 59% of SOTRs after 2 doses and 63% of SOTRs after 3 doses had a detectable antibody response. Multiple baseline cytokines were elevated in SOTRs versus HCs. There was no significant difference in baseline cytokine levels between SOTRs with high versus low-titer antibodies after 2 doses of vaccine. However, as compared with poor antibody responders, SOTRs who went on to develop a high-titer antibody response to a third dose of vaccine had significantly higher prethird dose levels of several innate immune cytokines including IL-17, IL-2Ra, IL-6, IP-10, MIP-1α, and TNF-α (false discovery rates < 0.05).

CONCLUSIONS

A specific inflammatory profile may be associated with developing higher antibodies in response to a third dose of SARS-CoV-2 vaccine in SOTRs.

A third dose of SARS-CoV-2 vaccine increases neutralizing antibodies against variants of concern in solid organ transplant recipients

Vaccine-induced SARS-CoV-2 antibody responses are attenuated in solid organ transplant recipients (SOTRs) and breakthrough infections are more common. Additional SARS-CoV-2 vaccine doses increase anti-spike IgG in some SOTRs, but it is uncertain whether neutralization of variants of concern (VOCs) is enhanced. We tested 47 SOTRs for clinical and research anti-spike IgG, pseudoneutralization (ACE2 blocking), and live-virus neutralization (nAb) against VOCs before and after a third SARS-CoV-2 vaccine dose (70% mRNA, 30% Ad26.COV2.S) with comparison to 15 healthy controls after two mRNA vaccine doses. We used correlation analysis to compare anti-spike IgG assays and focused on thresholds associated with neutralization. A third SARS-CoV-2 vaccine dose increased median total anti-spike (1.6-fold), pseudoneutralization against VOCs (2.5-fold vs. Delta), and neutralizing antibodies (1.4-fold against Delta). However, neutralization activity was significantly lower than healthy controls (p < .001); 32% of SOTRs had zero detectable nAb against Delta after third vaccination compared to 100% for controls. Correlation with nAb was seen at anti-spike IgG >4 Log10 (AU/ml) on the Euroimmun ELISA and >4 Log10 (AU/ml) on the MSD research assay. These findings highlight benefits of a third vaccine dose for some SOTRs and the need for alternative strategies to improve protection in a significant subset of this population.

The Serological Sciences Network (SeroNet) for COVID-19: Depth and Breadth of Serology Assays and Plans for Assay Harmonization

Background

In October 2020, the National Cancer Institute (NCI) Serological Sciences Network (SeroNet) was established to study the immune response to COVID-19, and "to develop, validate, improve, and implement serological testing and associated technologies." SeroNet is comprised of 25 participating research institutions partnering with the Frederick National Laboratory for Cancer Research (FNLCR) and the SeroNet Coordinating Center. Since its inception, SeroNet has supported collaborative development and sharing of COVID-19 serological assay procedures and has set forth plans for assay harmonization.

Methods

To facilitate collaboration and procedure sharing, a detailed survey was sent to collate comprehensive assay details and performance metrics on COVID-19 serological assays within SeroNet. In addition, FNLCR established a protocol to calibrate SeroNet serological assays to reference standards, such as the U.S. SARS-CoV-2 serology standard reference material and First WHO International Standard (IS) for anti-SARS-CoV-2 immunoglobulin (20/136), to facilitate harmonization of assay reporting units and cross-comparison of study data.

Results

SeroNet institutions reported development of a total of 27 ELISA methods, 13 multiplex assays, 9 neutralization assays, and use of 12 different commercial serological methods. FNLCR developed a standardized protocol for SeroNet institutions to calibrate these diverse serological assays to reference standards.

Conclusions

SeroNet institutions have established a diverse array of COVID-19 serological assays to study the immune response to SARS-CoV-2 virus and vaccines. Calibration of SeroNet serological assays to harmonize results reporting will facilitate future pooled data analyses and study cross-comparisons.

Differences and disparities in seasonal influenza vaccine, acceptance, adverse reactions, and coverage by age, sex, gender, and race

BACKGROUND

Influenza is a significant threat to public health worldwide. Despite the widespread availability of effective and generally safe vaccines, the acceptance and coverage of influenza vaccines are significantly lower than recommended. Sociodemographic variables are known to be potential predictors of differential influenza vaccine uptake and outcomes.

OBJECTIVES

This review aims to (1) identify how sociodemographic characteristics such as age, sex, gender, and race may influence seasonal influenza vaccine acceptance and coverage; and (2) evaluate the role of these sociodemographic characteristics in differential adverse reactions among vaccinated individuals.

METHODS

PubMed was used as the database to search for published literature in three thematic areas related to the seasonal influenza vaccine - vaccine acceptance, adverse reactions, and vaccine coverage.

RESULTS

A total of 3249 articles published between 2010 and 2020 were screened and reviewed, of which 39 studies were included in this literature review. By the three thematic areas, 17 studies assessed vaccine acceptance, 8 studies focused on adverse reactions, and 14 examined coverage of the seasonal influenza vaccine. There were also two studies that focused on more than one of the areas of interest.

CONCLUSION

Each of the four sociodemographic predictors - age, sex, race, and gender - were found to significantly influence vaccine acceptance, receipt and outcomes in this review.

Sex-specific effects of age and body mass index on antibody responses to seasonal influenza vaccines in healthcare workers

Healthcare institutions with mandatory influenza vaccination policies have over 90% vaccination rates among healthcare workers (HCWs) resulting in a population that has received the influenza vaccine in many, consecutive years. This study explored the impact of sex and other host factors in pre- and post-vaccination neutralizing antibody (nAb) titers and seroconversion against the H1N1 and H3N2 influenza A viruses (IAVs) among HCWs enrolled into a cross-sectional serosurvey during the annual Johns Hopkins Hospital employee vaccination campaign in the 2017-18 and 2018-19 seasons. The study enrolled 111 participants (male = 38, female = 73) in 2017-18 and 163 (male = 44, female = 119) in 2018-19. Serum samples were collected immediately prior to vaccination and approximately 28 days later and nAb titers to vaccine strains determined. An intersectional approach was used to disaggregate the combined effects of sex with age and body mass index (BMI) in the nAb response. Differences between the pre- or post-vaccination geometric mean nAb titers between male and female HCWs were not observed. Male HCWs were 2.86 times more likely to seroconvert compared to female HCWs in 2017-2018, but the same trend was not observed in the following year. When data were disaggregated by age and sex, older female HCWs had higher H1N1 pre- and post-vaccination nAb titers compared to male HCWs in the same age group for both vaccination campaign seasons. In both years, the decline in H3N2 pre-vaccination titers with increasing BMI was greater in female than male HCW. The sex-specific effects of age and BMI on nAb responses to seasonal influenza vaccines require greater consideration.

Female-biased effects of aging on a chimeric hemagglutinin stalk-based universal influenza virus vaccine in mice

To determine if biological sex and age intersect to affect universal influenza vaccine-induced immunity, adult and aged male and female C57BL/6 mice were sequentially immunized with a chimeric-hemagglutinin (cHA) stalk-based H1 vaccine. Adult mice developed greater quantity and quality of H1-stalk antibodies, that were more cross-reactive with other group 1, but not group 2, influenza viruses, than aged mice. The vaccine did not induce neutralizing or hemagglutination inhibition antibodies, but rather antibody-dependent cellular cytotoxicity, which was greater in adult than aged mice. Vaccinated adult mice were better protected than aged mice after challenge with 2009 H1N1 virus, experiencing less morbidity and having lower pulmonary virus titers. The age-associated decline in immunity and protection was consistently greater among females than males, with the reduction in immunity and protection for aged as compared with adult females often being the sole comparison driving the overall age-associated significant differences. The age-associated reduction in stalk-based immunity in females was not, however, associated with changes in estradiol. To determine if the better antibodies in adults could be utilized to protect aged mice, serum was passively transferred from vaccinated adult mice into naïve sex-matched aged mice. Even with transferred serum from young adult mice, aged females still suffered greater morbidity than aged males. These data suggest there are sex-dependent effects of aging on cHA-based universal influenza virus vaccine-induced immunity that cannot be reversed through transfer of serum from young animals. The lack of consideration of sex-specific effects of aging on immunity could hinder efforts toward universal vaccines.

Adaptive immune responses in vaccinated patients with symptomatic SARS-CoV-2 Alpha infection

Benchmarks for protective immunity from infection or severe disease after SARS-CoV-2 vaccination are still being defined. Here, we characterized virus neutralizing and ELISA antibody levels, cellular immune responses, and viral variants in 4 separate groups: healthy controls (HCs) weeks (early) or months (late) following vaccination in comparison with symptomatic patients with SARS-CoV-2 after partial or full mRNA vaccination. During the period of the study, most symptomatic breakthrough infections were caused by the SARS-CoV-2 Alpha variant. Neutralizing antibody levels in the HCs were sustained over time against the vaccine parent virus but decreased against the Alpha variant, whereas IgG titers and T cell responses against the parent virus and Alpha variant declined over time. Both partially and fully vaccinated patients with symptomatic infections had lower virus neutralizing antibody levels against the parent virus than the HCs, similar IgG antibody titers, and similar virus-specific T cell responses measured by IFN-γ. Compared with HCs, neutralization activity against the Alpha variant was lower in the partially vaccinated infected patients and tended to be lower in the fully vaccinated infected patients. In this cohort of breakthrough infections, parent virus neutralization was the superior predictor of breakthrough infections with the Alpha variant of SARS-CoV-2.

A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2 protects against disease and elicits neutralizing antibodies to wild-type and Delta variants

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, desirability of different routes of administration, and emergence of SARS-CoV-2 variants such as the Delta variant. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden Syrian hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titres of blood anti-RBD IgG as well as detectable mucosal responses. Neutralizing antibody activity against wild-type and Delta variants was evident in all vaccinated subjects. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided body mass loss, had lower virus titres in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches.