scholarly journals BNT162b2 boosted immune responses six months after heterologous or homologous ChAdOx1nCoV-19/BNT162b2 vaccination against COVID-19

Author(s):  
Georg Behrens ◽  
Joana Barros-Martins ◽  
Anne Cossmann ◽  
Gema Morillas Ramos ◽  
Metodi Stankov ◽  
...  

Abstract Reports suggest that COVID-19 vaccine effectiveness is decreasing, either due to waning immune protection, emergence of new variants of concern, or both. Heterologous prime/boost vaccination with a vector-based approach (ChAdOx-1nCov-19, ChAd) followed by an mRNA vaccine (e.g. BNT162b2, BNT) appeared to be superior in inducing protective immunity, and large scale second booster vaccination is ongoing. However, data comparing declining immunity after homologous and heterologous vaccination as well as effects of a third vaccine application after heterologous ChAd/BNT vaccination are lacking. We longitudinally monitored immunity in ChAd/ChAd (n=41) and ChAd/BNT (n=88) vaccinated individuals and assessed the impact of a second booster with BNT in both groups. The second booster greatly augmented waning anti-spike IgG but only moderately increased spike-specific CD4+ and CD8+ T cells in both groups to cell frequencies already present after the boost. More importantly, the second booster efficiently restored neutralizing antibody responses against Alpha, Beta, Gamma, and Delta, but neutralizing activity against B.1.1.529 (Omicron) stayed severely impaired. Our data suggest that inferior SARS-CoV-2 specific immune responses after homologous ChAd/ChAd vaccination can be cured by a heterologous BNT vaccination. However, prior heterologous ChAd/BNT vaccination provides no additional benefit for spike-specific T cell immunity or neutralizing Omicron after the second boost.

2021 ◽  
Author(s):  
Georg MN Behrens ◽  
Joana Barros-Martins ◽  
Anne Cossmann ◽  
Gema Morillas Ramos ◽  
Metodi V Stankov ◽  
...  

Reports suggest that COVID-19 vaccine effectiveness is decreasing, either due to waning immune protection, emergence of new variants of concern, or both. Heterologous prime/boost vaccination with a vector-based approach (ChAdOx-1nCov-19, ChAd) followed by an mRNA vaccine (e.g. BNT162b2, BNT) appeared to be superior in inducing protective immunity, and large scale second booster vaccination is ongoing. However, data comparing declining immunity after homologous and heterologous vaccination as well as effects of a third vaccine application after heterologous ChAd/BNT vaccination are lacking. We longitudinally monitored immunity in ChAd/ChAd (n=41) and ChAd/BNT (n=88) vaccinated individuals and assessed the impact of a second booster with BNT in both groups. The second booster greatly augmented waning anti-spike IgG but only moderately increased spike-specific CD4+ and CD8+ T cells in both groups to cell frequencies already present after the boost. More importantly, the second booster efficiently restored neutralizing antibody responses against Alpha, Beta, Gamma, and Delta, but neutralizing activity against B.1.1.529 (Omicron) stayed severely impaired. Our data suggest that inferior SARS-CoV-2 specific immune responses after homologous ChAd/ChAd vaccination can be cured by a heterologous BNT vaccination. However, prior heterologous ChAd/BNT vaccination provides no additional benefit for spike-specific T cell immunity or neutralizing Omicron after the second boost.


2021 ◽  
Author(s):  
Eleni Vatzia ◽  
Elizabeth Allen ◽  
Tanuja Manjegowda ◽  
Susan Morris ◽  
Adam McNee ◽  
...  

Abstract There is a critical need to develop superior influenza vaccines that provide broader protection. Influenza vaccines are traditionally tested in naïve animals, although humans are exposed to influenza in the first years of their lives, but the impact of prior influenza exposure on vaccine induced immune responses has not been well studied. Pigs are an important natural host for influenza, are a source of pandemic viruses, and are an excellent model for human influenza. Here we investigated the immunogenicity of the ChAdOx2 viral vectored vaccine, expressing influenza nucleoprotein, matrix protein 1 and neuraminidase in H1N1pdm09 pre-exposed pigs. We evaluated the importance of route of administration by comparing intra-nasal, aerosol and intra-muscular immunizations. Aerosol delivery boosted the local lung T cell and antibody responses, while intra-muscular immunization boosted systemic immunity. These results will inform how best to deliver vaccines in order to harness optimal protective immunity.


2020 ◽  
Author(s):  
Morgan L. Sherer ◽  
Jun Lei ◽  
Patrick Creisher ◽  
Minyoung Jang ◽  
Ramya Reddy ◽  
...  

AbstractImportanceThe effects of SARS-CoV-2 infection on immune responses during pregnancy have not been systematically evaluated.ObjectiveTo assess the impact of SARS-CoV-2 infection during pregnancy on inflammatory and humoral responses in maternal and fetal samples and compare antibody responses to SARS-CoV-2 among pregnant and non-pregnant women.DesignImmune responses to SARS-CoV-2 were analyzed using samples from pregnant and non-pregnant women who had either tested positive or negative for SARS-CoV-2. We measured, proinflammatory and placental cytokine mRNAs, neonatal Fc receptor (FcRn) receptor expression, and tetanus antibody transfer in maternal and cord blood samples. Additionally, we measured anti-spike (S) IgG, anti-S-receptor binding domain (RBD) IgG, and neutralizing antibody (nAb) responses to SARS-CoV-2 in serum or plasma collected from non-pregnant women, pregnant women, and cord blood.SettingJohns Hopkins Hospital (JHH)ParticipantsPregnant women were recruited through JHH outpatient obstetric clinics and the JHH Labor & Delivery unit. Non-pregnant women were recruited after receiving outpatient SARS-CoV-2 testing within Johns Hopkins Health System, USA. Adult non-pregnant women with positive RT-PCR results for SARS-CoV-2, within the age range of 18-48 years, were included in the study.ExposuresSARS-CoV-2Main Outcomes and MeasuresParticipant demographic characteristics, antibody titers, cytokine mRNA expression, and FcRn receptor expression.ResultsSARS-COV-2 positive pregnant women expressed more IL1β, but not IL6, in blood samples collected within 14 days versus > 14 days after a confirmed SARS-CoV-2 test, with similar patterns observed in the fetal side of placentas, particularly among asymptomatic pregnant women. Pregnant women with confirmed SARS-CoV-2 infection also had reduced anti-S-RBD IgG titers and were less likely to have detectable nAb as compared with non-pregnant women. Although SARS-CoV-2 infection did not disrupt FcRn expression in the placenta, maternal transfer of nAb was inhibited by SARS-CoV-2 infection during pregnancy.Conclusions and RelevanceSARS-CoV-2 infection during pregnancy was characterized by placental inflammation and reduced antiviral antibody responses, which may impact the efficacy of COVID-19 therapeutics in pregnancy. The long-term implications of placental inflammation for neonatal health also requires greater consideration.


2021 ◽  
Author(s):  
Malika Aid ◽  
Samuel Vidal ◽  
Cesar Piedra-Mora ◽  
Sarah Ducat ◽  
Chi Chan ◽  
...  

Syrian golden hamsters exhibit features of severe disease after SARS-CoV-2 challenge and are therefore useful models of COVID-19 pathogenesis and prevention with vaccines. Recent studies have shown that SARS-CoV-2 infection stimulates type I interferon, myeloid, and inflammatory signatures similar to human disease, and that weight loss can be prevented with vaccines. However, the impact of vaccination on transcriptional programs associated with COVID-19 pathogenesis and protective adaptive immune responses is unknown. Here we show that SARS-CoV-2 challenge in hamsters stimulates antiviral, myeloid, and inflammatory programs as well as signatures of complement and thrombosis associated with human COVID-19. Notably, single dose immunization with Ad26.COV2.S, an adenovirus serotype 26 vector (Ad26)-based vaccine expressing a stabilized SARS-CoV-2 spike protein, prevents the upregulation of these pathways such that the gene expression profiles of vaccinated hamsters are comparable to uninfected animals. Finally, we show that Ad26.COV2.S vaccination induces T and B cell signatures that correlate with binding and neutralizing antibody responses. These data provide further insights into the mechanisms of Ad26.COV2.S based protection against severe COVID-19 in hamsters.


2017 ◽  
Vol 214 (9) ◽  
pp. 2563-2572 ◽  
Author(s):  
Spencer W. Stonier ◽  
Andrew S. Herbert ◽  
Ana I. Kuehne ◽  
Ariel Sobarzo ◽  
Polina Habibulin ◽  
...  

Until recently, immune responses in filovirus survivors remained poorly understood. Early studies revealed IgM and IgG responses to infection with various filoviruses, but recent outbreaks have greatly expanded our understanding of filovirus immune responses. Immune responses in survivors of Ebola virus (EBOV) and Sudan virus (SUDV) infections have provided the most insight, with T cell responses as well as detailed antibody responses having been characterized. Immune responses to Marburg virus (MARV), however, remain almost entirely uncharacterized. We report that immune responses in MARV survivors share characteristics with EBOV and SUDV infections but have some distinct differences. MARV survivors developed multivariate CD4+ T cell responses but limited CD8+ T cell responses, more in keeping with SUDV survivors than EBOV survivors. In stark contrast to SUDV survivors, rare neutralizing antibody responses in MARV survivors diminished rapidly after the outbreak. These results warrant serious consideration for any vaccine or therapeutic that seeks to be broadly protective, as different filoviruses may require different immune responses to achieve immunity.


2015 ◽  
Vol 23 (2) ◽  
pp. 84-94 ◽  
Author(s):  
David R. Martinez ◽  
Sallie R. Permar ◽  
Genevieve G. Fouda

ABSTRACTExtensive studies have demonstrated that infant immune responses are distinct from those of adults. Despite these differences, infant immunization can elicit protective immune responses at levels comparable to or, in some cases, higher than adult immune responses to many vaccines. To date, only a few HIV vaccine candidates have been tested in infant populations, and none of them evaluated vaccine efficacy. Recent exciting studies showing that HIV-infected infants can develop broad neutralizing antibody responses and that some HIV vaccine regimens can elicit high levels of potentially protective antibodies in infants provide support for the development and testing of HIV vaccines in pediatric populations. In this review, we discuss the differences in adult and infant immune responses in the setting of HIV infection and vaccination.


npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Martijn A. Langereis ◽  
Irina C. Albulescu ◽  
Judith Stammen-Vogelzangs ◽  
Morindy Lambregts ◽  
Ken Stachura ◽  
...  

AbstractEarly in the SARS-CoV-2 pandemic concerns were raised regarding infection of new animal hosts and the effect on viral epidemiology. Infection of other animals could be detrimental by causing clinical disease, allowing further mutations, and bares the risk for the establishment of a non-human reservoir. Cats were the first reported animals susceptible to natural and experimental infection with SARS-CoV-2. Given the concerns these findings raised, and the close contact between humans and cats, we aimed to develop a vaccine candidate that could reduce SARS-CoV-2 infection and in addition to prevent spread among cats. Here we report that a Replicon Particle (RP) vaccine based on Venezuelan equine encephalitis virus, known to be safe and efficacious in a variety of animal species, could induce neutralizing antibody responses in guinea pigs and cats. The design of the SARS-CoV-2 spike immunogen was critical in developing a strong neutralizing antibody response. Vaccination of cats was able to induce high neutralizing antibody responses, effective also against the SARS-CoV-2 B.1.1.7 variant. Interestingly, in contrast to control animals, the infectious virus could not be detected in oropharyngeal or nasal swabs of vaccinated cats after SARS-CoV-2 challenge. Correspondingly, the challenged control cats spread the virus to in-contact cats whereas the vaccinated cats did not transmit the virus. The results show that the RP vaccine induces protective immunity preventing SARS-CoV-2 infection and transmission. These data suggest that this RP vaccine could be a multi-species vaccine useful to prevent infection and spread to and between animals should that approach be required.


2021 ◽  
Vol 118 (45) ◽  
pp. e2110817118
Author(s):  
Dengning Xia ◽  
Rui Jin ◽  
Gaurav Byagathvalli ◽  
Huan Yu ◽  
Ling Ye ◽  
...  

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array (“ePatch”) for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin’s epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.


2020 ◽  
Author(s):  
Matthew L. Goodwin ◽  
Helen S. Webster ◽  
Hsuan-Yuan Wang ◽  
Jennifer A. Jenks ◽  
Cody S. Nelson ◽  
...  

AbstractHuman cytomegalovirus (HCMV) is the most common congenital infection, and the leading nongenetic cause of sensorineural hearing loss (SNHL) in newborns globally. A gB subunit vaccine administered with adjuvent MF59 (gB/MF59) is the most efficacious tested to-date, achieving 50% efficacy in preventing infection of HCMV-seronegative mothers. We recently discovered that gB/MF59 vaccination elicited primarily non-neutralizing antibody responses, that HCMV strains acquired by vaccinees more often included strains with gB genotypes that are distinct from the vaccine antigen, and that protection against HCMV acquisition correlated with ability of vaccine-elicited antibodies to bind to membrane associated gB. Thus, we hypothesized that gB-specific non-neutralizing antibody binding breadth and function are dependent on their epitope and genotype specificity as well as their ability to interact with membrane-associated gB. Twenty-four gB-specific monoclonal antibodies (mAbs) isolated from naturally HCMV-infected individuals were mapped for gB domain specificity by binding antibody multiplex assay (BAMA) and for genotype preference binding to membrane-associated gB presented on transfected cells. We defined their non-neutralizing functions including antibody dependent cellular phagocytosis (ADCP) and antibody dependent cellular cytotoxicity (ADCC). The isolated gB-specific non-neutralizing mAbs were primarily specific for Domain II and linear antigenic domain 2 site 2 (AD2). We observed variability in mAb gB genotype binding preference, with increased binding to gB genotypes 2 and 4. Functional studies identified two gB-specific mAbs that facilitate ADCP and have binding specificities of AD2 and Domain II. This investigation provides novel understanding on the impact of gB domain specificity and antigenic variability on gB-specific non-neutralizing antibody responses.ImportanceHCMV is the most common congenital infection worldwide, but development of a successful vaccine remains elusive. gB-specific non-neutralizing mAbs, represent a distinct anti-HCMV Ab subset implicated in the protection against primary infection during numerous phase-II gB/MF59 vaccine trials. By studying non-neutralizing gB-specific mAbs from naturally infected individuals, this study provides novel characterization of binding site specificity, genotypic preference, and effector cell functions mediated by mAbs elicited in natural infection. We found that a panel of twenty-four gB-specific non-neutralizing mAbs bind across multiple regions of the gB protein, traditionally through to be targeted by neutralizing mAbs only, and bind differently to gB depending if the protein is soluble versus embedded in a membrane. This investigation provides novel insight into the gB-specific binding characteristics and effector cell functions mediated by non-neutralizing gB-specific mAbs elicited through natural infection, providing new endpoints for future vaccine development.


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