Publications by authors named "Galit Alter"

Background: Tuberculosis (TB), caused by (Mtb), is among the leading causes of death from an infectious agent among children worldwide. Children represent a particularly vulnerable population due to the greater challenges in diagnosis and the higher risk of progression to severe forms of the disease. However, whether different pediatric outcomes relate to distinct immunologic responses remains incompletely understood.

View Article and Find Full Text PDF

Introduction: Respiratory syncytial virus (RSV) causes significant lower-respiratory-tract disease in high-risk groups. A phase IIb trial showed that a combination vaccine of Ad26-vectored prefusion RSV F (Ad26.preF) plus soluble prefusion F protein (SpreF) was 80 % protective, yet the longevity and functionality of these humoral responses are unknown.

View Article and Find Full Text PDF

Variation in malaria infection risk, a product of disease exposure and immunity, is poorly understood. We genotypically profiled over 13,000 blood samples from a six-year longitudinal cohort in Mali to characterize malaria infection dynamics with detail. We generated Plasmodium falciparum amplicon sequencing data from 464 participants (aged 3 months - 25 years) across the six-month 2011 transmission season and profiled a subset of 120 participants across the subsequent five annual transmission seasons.

View Article and Find Full Text PDF

The first-ever recent Marburg virus (MARV) outbreak in Tanzania and recent emergences in Rwanda, Ghana and Equatorial Guinea underscore the importance of therapeutic or vaccine development against the virus, for which none are approved. mRNA vaccines were proven successful in a pandemic-response to severe acute respiratory syndrome coronavirus-2, making it an appealing platform to target pathogenic emerging viruses. Here, we develop 1-methyl-pseudouridine-modified mRNA vaccines formulated in lipid nanoparticles (LNP) targeting the glycoproteins (GP) of MARV and the closely-related Ravn virus (RAVV).

View Article and Find Full Text PDF

The global immune landscape of SARS-CoV-2 has progressively shifted from a naïve population several years ago to a population that possesses immunity to the virus through infection, vaccination, or a combination of both, known as hybrid immunity. Hybrid immunity offers a prolonged period of transmission-blocking activity, likely related to enhanced tissue-resident immunity, but also has been shown to be linked to broader humoral and cellular immune responses. Compared with vaccination or infection alone, the collective data have demonstrated that hybrid immunity offers enhanced protection against disease.

View Article and Find Full Text PDF

Patients with multiple myeloma (MM) and Waldenström macroglobulinemia (WM) have increased risk of severe COVID-19. Impaired humoral responses to the primary vaccination series against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in MM and WM patients, but impact of booster vaccinations and functional status of the elicited antibodies is unknown. We performed a prospective cohort study investigating SARS-CoV-2 vaccination in MM (n=93) and WM (n=48) patients.

View Article and Find Full Text PDF

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), a leading cause of death by an infectious disease globally, has no efficacious vaccine. Antibodies are implicated in M. tuberculosis control, but the mechanisms of action remain poorly understood.

View Article and Find Full Text PDF

Antibodies from primary dengue (DENV1-4) or Zika (ZIKV) virus infections can influence subsequent heterotypic infections, but their protective characteristics are not well defined. We analyzed pre-infection plasma samples from children in our Nicaraguan cohort study who later developed either dengue fever (DF; n = 31) or dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS; n = 33) upon secondary heterotypic DENV infection. Various antibody properties, notably antibody-dependent complement deposition, correlated with protection against DHF/DSS.

View Article and Find Full Text PDF

Antibodies mediate protection against a wide range of pathogens through binding and neutralizing the pathogen or through Fc-mediated effector functions. Human monoclonal antibodies (mAbs) CIS43LS and L9LS show high-affinity binding targeting distinct regions on the circumsporozoite protein (PfCSP) and are highly effective in preventing malaria in humans. However, the role of FcγR binding in protection by these mAbs has not been determined.

View Article and Find Full Text PDF

While control of Mycobacterium tuberculosis (Mtb) infection is generally understood to require Th1 cells and IFNγ, infection produces a spectrum of immunological and pathological phenotypes in diverse human populations. By characterizing Mtb infection in mouse strains that model the genetic heterogeneity of an outbred population, we identified strains that control Mtb comparably to a standard IFNγ-dependent mouse model but with substantially lower lung IFNγ levels. We report that these mice have a significantly altered CD4 T cell profile that specifically lacks the terminal effector Th1 subset and that this phenotype is detectable before infection.

View Article and Find Full Text PDF

The four dengue virus serotypes (DENV1-4) and the related Zika flavivirus (ZIKV) are major public health concerns worldwide. Primary immunity against ZIKV increases the risk of a subsequent severe DENV2 infection, presenting a significant challenge for developing safe and effective ZIKV vaccines. However, the mechanisms driving this phenomenon remain unclear.

View Article and Find Full Text PDF

Background: Lassa fever (LF) is a zoonotic haemorrhagic disease caused by Lassa virus (LASV), which is endemic in West African countries. The multimammate rat is the main animal reservoir and its geographic range is expected to expand due to influences like climate change and land usage, and this will place larger parts of Africa at risk. We conducted preclinical development on a promising experimental vaccine that allowed its advancement into human trials.

View Article and Find Full Text PDF

Some individuals, even when heavily exposed to an infectious tuberculosis patient, do not develop a specific T-cell response as measured by interferon-gamma release assay (IGRA). This could be explained by an IFN-γ-independent adaptive immune response, or an effective innate host response clearing Mycobacterium tuberculosis (Mtb) without adaptive immunity. In heavily exposed Indonesian tuberculosis household contacts (n = 1347), a persistently IGRA negative status was associated with presence of a BCG scar, and - especially among those with a BCG scar - with altered innate immune cells dynamics, higher heterologous (Escherichia coli-induced) proinflammatory cytokine production, and higher inflammatory proteins in the IGRA mitogen tube.

View Article and Find Full Text PDF

Intradermal Bacillus Calmette-Guérin (BCG) is the most widely administered vaccine, but it does not sufficiently protect adults against pulmonary tuberculosis. Recent studies in nonhuman primates show that intravenous BCG administration offers superior protection against (). We used single-cell analysis of bronchoalveolar lavage cells from rhesus macaques vaccinated via different routes and doses of BCG to identify alterations in the immune ecosystem in the airway following vaccination.

View Article and Find Full Text PDF

Analysis of multi-modal datasets can identify multi-scale interactions underlying biological systems, but can be beset by spurious connections due to indirect impacts propagating through an unmapped biological network. For example, studies in macaques have shown that BCG vaccination by an intravenous route protects against tuberculosis, correlating with changes across various immune data modes. To eliminate spurious correlations and identify critical immune interactions in a public multi-modal dataset (systems serology, cytokines, cytometry) of vaccinated macaques, we applied Markov Fields (MF), a data-driven approach that explains vaccine efficacy and immune correlations via multivariate network paths, without requiring large numbers of samples (i.

View Article and Find Full Text PDF

Analysis of multi-modal datasets can identify multi-scale interactions underlying biological systems but can be beset by spurious connections due to indirect impacts propagating through an unmapped biological network. For example, studies in macaques have shown that Bacillus Calmette-Guerin (BCG) vaccination by an intravenous route protects against tuberculosis, correlating with changes across various immune data modes. To eliminate spurious correlations and identify critical immune interactions in a public multi-modal dataset (systems serology, cytokines, and cytometry) of vaccinated macaques, we applied Markov fields (MFs), a data-driven approach that explains vaccine efficacy and immune correlations via multivariate network paths, without requiring large numbers of samples (i.

View Article and Find Full Text PDF

SARS-CoV-2 vaccine-acquired immunity provides robust cross-variant recognition, while infection-acquired immunity can be heterogenous, with disease severity often modulating post-recovery responses. We assessed antibody waning dynamics between infection- and vaccination-acquired immunity across variants of concern (VOC). mRNA vaccination induced potent, cross-VOC Spike recognition and functional responses, but waned more rapidly for Omicron Spike.

View Article and Find Full Text PDF

the causative agent of tuberculosis (TB), is a leading cause of death by an infectious disease globally, with no efficacious vaccine. Antibodies are implicated in control, but the mechanisms of antibody action remain poorly understood. We assembled a library of TB monoclonal antibodies (mAb) and screened for the ability to restrict in mice, identifying protective antibodies targeting known and novel antigens.

View Article and Find Full Text PDF

Objectives: To determine the proportion of individuals with detectable antigen in plasma or serum after SARS-CoV-2 infection and the association of antigen detection with postacute sequelae of COVID-19 (PASC) symptoms.

Methods: Plasma and serum samples were collected from adults participating in four independent studies at different time points, ranging from several days up to 14 months post-SARS-CoV-2 infection. The primary outcome measure was to quantify SARS-CoV-2 antigens, including the S1 subunit of spike, full-length spike, and nucleocapsid, in participant samples.

View Article and Find Full Text PDF
Article Synopsis
  • Shigellosis is a major cause of diarrheal deaths in children under five, and there's currently no effective vaccine for Shigella infection, particularly in endemic areas.
  • Researchers in Bangladesh studied the antibody responses in both young children and older individuals with confirmed shigellosis to understand the differences in immune response.
  • Findings revealed that while higher antibody levels correlated with less severe disease, young children developed weaker and less effective immune responses compared to older individuals, which may hinder their ability to fight off Shigella effectively.
View Article and Find Full Text PDF

The COVID-19 pandemic placed the field of vaccinology squarely at the center of global consciousness, emphasizing the vital role of vaccines as transformative public health tools. The impact of vaccines was recently acknowledged by the award of the 2023 Nobel Prize in Physiology or Medicine to Katalin Kariko and Drew Weissman for their seminal contributions to the development of mRNA vaccines. Here, we provide a historic perspective on the key innovations that led to the development of some 27 licensed vaccines over the past two centuries and recent advances that promise to transform vaccines in the future.

View Article and Find Full Text PDF

In 2022, mpox virus (MPXV) spread worldwide, causing 99,581 mpox cases in 121 countries. Modified vaccinia Ankara (MVA) vaccine use reduced disease in at-risk populations but failed to deliver complete protection. Lag in manufacturing and distribution of MVA resulted in additional MPXV spread, with 12,000 reported cases in 2023 and an additional outbreak in Central Africa of clade I virus.

View Article and Find Full Text PDF
Article Synopsis
  • Hybrid immunity, which occurs after vaccination following infection, offers stronger protection against SARS-CoV-2 by enhancing immune response effectiveness.
  • The study compares immune profiles of individuals with infection only, vaccination only, and hybrid immunity, finding that hybrid immunity results in better antibody performance and activation of immune cells.
  • Results indicate that older adults particularly benefit from hybrid immunity, highlighting the need for vaccination strategies to consider age differences in immune responses.
View Article and Find Full Text PDF