scholarly journals The way of SARS-CoV-2 vaccine development: success and challenges

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yetian Dong ◽  
Tong Dai ◽  
Bin Wang ◽  
Lei Zhang ◽  
Ling-hui Zeng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Vaccine Development ◽  
Natural Infection ◽  
Wild Type ◽  
Mutational Hotspots ◽  
Long Term Changes ◽  
Induced Immunity ◽  
Shed Light

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). To halt the pandemic, multiple SARS-CoV-2 vaccines have been developed and several have been allowed for emergency use and rollout worldwide. With novel SARS-CoV-2 variants emerging and circulating widely, whether the original vaccines that were designed based on the wild-type SARS-CoV-2 were effective against these variants has been a contentious discussion. Moreover, some studies revealed the long-term changes of immune responses post SARS-CoV-2 infection or vaccination and the factors that might impact the vaccine-induced immunity. Thus, in this review, we have summarized the influence of mutational hotspots on the vaccine efficacy and characteristics of variants of interest and concern. We have also discussed the reasons that might result in discrepancies in the efficacy of different vaccines estimated in different trials. Furthermore, we provided an overview of the duration of immune responses after natural infection or vaccination and shed light on the factors that may affect the immunity induced by the vaccines, such as special disease conditions, sex, and pre-existing immunity, with the aim of aiding in combating COVID-19 and distributing SARS-CoV-2 vaccines under the prevalence of diverse SARS-CoV-2 variants.

scholarly journals Waning Immunity and Microbial Vaccines—Workshop of the National Institute of Allergy and Infectious Diseases

2017 ◽  
Vol 24 (7) ◽  
Author(s):  
Xin-Xing Gu ◽  
Stanley A. Plotkin ◽  
Kathryn M. Edwards ◽  
Alessandro Sette ◽  
Kingston H. G. Mills ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Immune Responses ◽  
New Technologies ◽  
Vaccine Development ◽  
Natural Infection ◽  
Complex Life Cycle ◽  
Future Research ◽  
Content Type ◽  
Waning Immunity

ABSTRACT Since the middle of the 20th century, vaccines have made a significant public health impact by controlling infectious diseases globally. Although long-term protection has been achieved with some vaccines, immunity wanes over time with others, resulting in outbreaks or epidemics of infectious diseases. Long-term protection against infectious agents that have a complex life cycle and antigenic variation remains a key challenge. Novel strategies to characterize the short- and long-term immune responses to vaccines and to induce immune responses that mimic natural infection have recently emerged. New technologies and approaches in vaccinology, such as adjuvants, delivery systems, and antigen formulations, have the potential to elicit more durable protection and fewer adverse reactions; together with in vitro systems, these technologies have the capacity to model and accelerate vaccine development. The National Institute of Allergy and Infectious Diseases (NIAID) held a workshop on 19 September 2016 that focused on waning immunity to selected vaccines (for Bordetella pertussis, Salmonella enterica serovar Typhi, Neisseria meningitidis, influenza, mumps, and malaria), with an emphasis on identifying knowledge gaps, future research needs, and how this information can inform development of more effective vaccines for infectious diseases.

scholarly journals COVID-19: Mechanisms of Vaccination and Immunity

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 404 ◽  
Author(s):  
Daniel E. Speiser ◽  
Martin F. Bachmann
Keyword(s):  
Immune Responses ◽  
Clinical Management ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Public Life ◽  
High Affinity ◽  
Vaccination Strategies ◽  
Detailed Evaluation ◽  
Pros And Cons

Vaccines are needed to protect from SARS-CoV-2, the virus causing COVID-19. Vaccines that induce large quantities of high affinity virus-neutralizing antibodies may optimally prevent infection and avoid unfavorable effects. Vaccination trials require precise clinical management, complemented with detailed evaluation of safety and immune responses. Here, we review the pros and cons of available vaccine platforms and options to accelerate vaccine development towards the safe immunization of the world’s population against SARS-CoV-2. Favorable vaccines, used in well-designed vaccination strategies, may be critical for limiting harm and promoting trust and a long-term return to normal public life and economy.

scholarly journals Two Complex, Adenovirus-Based Vaccines That Together Induce Immune Responses to All Four Dengue Virus Serotypes

2006 ◽  
Vol 14 (2) ◽  
pp. 182-189 ◽  
Author(s):  
David H. Holman ◽  
Danher Wang ◽  
Kanakatte Raviprakash ◽  
Nicholas U. Raja ◽  
Min Luo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Development ◽  
De Novo ◽  
Natural Infection ◽  
Hemorrhagic Fever ◽  
Virus Infections ◽  
Dengue Vaccine ◽  
Membrane Antigens ◽  
Dengue Virus Serotypes

ABSTRACT Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

scholarly journals Differential antibody dynamics to SARS-CoV-2 infection and vaccination

2021 ◽  
Author(s):  
Yuezhou Chen ◽  
Pei Tong ◽  
Noah B. Whiteman ◽  
Ali Sanjari Moghaddam ◽  
Adam Zuiani ◽  
...  
Keyword(s):  
Immune Responses ◽  
B Cell ◽  
Somatic Mutation ◽  
Post Infection ◽  
Vaccine Strategy ◽  
Specific Antibodies ◽  
Antibody Dynamics ◽  
Induced Immunity ◽  
Original Virus

ABSTRACTOptimal immune responses furnish long-lasting (durable) antibodies protective across dynamically mutating viral variants (broad). To assess robustness of mRNA vaccine-induced immunity, we compared antibody durability and breadth after SARS-CoV-2 infection and vaccination. While vaccination delivered robust initial virus-specific antibodies with some cross-variant coverage, pre-variant SARS-CoV-2 infection-induced antibodies, while modest in magnitude, showed highly stable long-term antibody dynamics. Vaccination after infection induced maximal antibody magnitudes with enhanced longitudinal stability while infection-naïve vaccinee antibodies fell with time to post-infection-alone levels. The composition of antibody neutralizing activity to variant relative to original virus also differed between groups, with infection-induced antibodies demonstrating greater relative breadth. Differential antibody durability trajectories favored COVID-19-recovered subjects with dual memory B cell features of greater early antibody somatic mutation and cross-coronavirus reactivity. By illuminating an infection-mediated antibody breadth advantage and an anti-SARS-CoV-2 antibody durability-enhancing function conferred by recalled immunity, these findings may serve as guides for ongoing vaccine strategy improvement.

scholarly journals Predicting the risk of re-infection from SARS-CoV-2 using the known pattern of adaptive immune response to previous human coronavirus outbreaks

2020 ◽  
Author(s):  
Ademola Samuel Ojo ◽  
Paul Toluwatope Okediji ◽  
Ayotemide P. Akin-Onitolo ◽  
Olusegun S. Ojo ◽  
Oluyinka Oladele Opaleye
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Adaptive Immune Response ◽  
The Body ◽  
Short Term ◽  
Adaptive Immune ◽  
Short And Long Term

This paper attempts to answer the question: are recovered COVID-19 patients protected from re-infection? This review draws evidence from comparisons between immune responses to Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Middle East Respiratory Syndrome coronavirus (MERS-CoV), which are phylogenetically closely related to Severe Acute Respiratory Syndrome coronavirus type 2 (SARS-CoV-2). Relevant studies were identified and reviewed based on searches conducted using PubMed. Full-text original studies on short- and long-term immune responses to human coronaviruses were included. The immune dysfunction and clinical manifestations in SARS-CoV-2, SARS-CoV, and MERS-CoV were found to be similar. Infections with SARS-CoV and MERS-CoV trigger the production of antibodies and memory B- and T-cells. Serum IgM is detectable within 7 days, peak at 21-30 days and become undetectable by 180 days. IgG is detectable at 7 days, peak at 90 days, and decline to undetected levels by 2 years post-infection. Memory B- and T-cells persist in the body for up to 2 and 6 years respectively after initial infection. The short-term risk of SARS-CoV-2 re-infection is predictably low based on similarities in the short term adaptive immune response to kindred coronaviruses. However, more research will be required to determine the long-term adaptive immunity to SARS-CoV-2 and factors that may influence the existence of short- and long-term immunity against the virus.

scholarly journals Recombinant Herpesvirus Vectors: Durable Immune Responses and

2021 ◽  
Author(s):  
Isabelle M. Castro ◽  
Michael J. Ricciardi ◽  
Lucas Gonzalez-Nieto ◽  
Eva G. Rakasz ◽  
Jeffrey D. Lifson ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Vaccine Development ◽  
Rhesus Macaques ◽  
Antigen Expression ◽  
Challenge Virus ◽  
Immunodeficiency Virus ◽  
Herpesvirus Vector ◽  
Gamma Herpesvirus

A prophylactic vaccine that confers durable protection against human immunodeficiency virus (HIV) would provide a valuable tool to prevent new HIV/AIDS cases. As herpesviruses establish lifelong infections that remain largely subclinical, the use of persistent herpesvirus vectors to deliver HIV antigens may facilitate the induction of long-term anti-HIV immunity. We previously developed recombinant (r) forms of the gamma-herpesvirus rhesus monkey rhadinovirus (rRRV) expressing a replication-incompetent, near-full-length simian immunodeficiency virus (SIVnfl) genome. We recently showed that 8/16 rhesus macaques (RMs) vaccinated with a rDNA/rRRV-SIVnfl regimen were significantly protected against intrarectal (IR) challenge with SIVmac239. Here we investigated the longevity of this vaccine-mediated protection. Despite receiving no additional booster immunizations, the protected rDNA/rRRV-SIVnfl vaccinees maintained detectable cellular and humoral anti-SIV immune responses for more than 1.5 years after the rRRV boost. To assess if these responses were still protective, the rDNA/rRRV-SIVnfl vaccinees were subjected to a second round of marginal-dose IR SIVmac239 challenges, with eight SIV-naïve RMs serving as concurrent controls. After three SIV exposures, 8/8 control animals became infected, compared to 3/8 vaccinees. This difference in SIV acquisition was statistically significant (P = 0.0035). The three vaccinated monkeys that became infected exhibited significantly lower viral loads than those in unvaccinated controls. Collectively, these data illustrate the ability of rDNA/rRRV-SIVnfl vaccination to provide long-term immunity against stringent mucosal challenges with SIVmac239. Future work is needed to identify the critical components of this vaccine-mediated protection and the extent to which it can tolerate sequence mismatches in the challenge virus. IMPORTANCE We report on the long-term follow-up of a group of rhesus macaques (RMs) that received an AIDS vaccine regimen and were subsequently protected against rectal acquisition of simian immunodeficiency virus (SIV) infection. The vaccination regimen employed included a live recombinant herpesvirus vector that establishes persistent infection in RMs. Consistent with the recurrent SIV antigen expression afforded by this herpesvirus vector, vaccinees maintained detectable SIV-specific immune responses for more than 1.5 years after the last vaccination. Importantly, these vaccinated RMs were significantly protected against a second round of rectal SIV exposures performed one year after the first SIV challenge phase. These results are relevant for HIV vaccine development because they show the potential of herpesvirus-based vectors to maintain functional antiretroviral immunity without the need for repeated boosting.

scholarly journals Enteric neuroimmune interactions coordinate intestinal responses in health and disease

2021 ◽  
Author(s):  
Haozhe Wang ◽  
Jaime P. P. Foong ◽  
Nicola L. Harris ◽  
Joel C. Bornstein
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Immune Responses ◽  
Gi Tract ◽  
Neuroimmune Interactions ◽  
Long Term Changes ◽  
Infection And Inflammation ◽  
Health And Disease ◽  
Post Infectious

AbstractThe enteric nervous system (ENS) of the gastrointestinal (GI) tract interacts with the local immune system bidirectionally. Recent publications have demonstrated that such interactions can maintain normal GI functions during homeostasis and contribute to pathological symptoms during infection and inflammation. Infection can also induce long-term changes of the ENS resulting in the development of post-infectious GI disturbances. In this review, we discuss how the ENS can regulate and be regulated by immune responses and how such interactions control whole tissue physiology. We also address the requirements for the proper regeneration of the ENS and restoration of GI function following the resolution of infection.

scholarly journals Vaccines against Coronavirus Disease: Target Proteins, Immune Responses, and Status of Ongoing Clinical Trials

2020 ◽  
Vol 14 (4) ◽  
pp. 2253-2263
Author(s):  
Rike Syahniar ◽  
Maria Berlina Purba ◽  
Heri Setiyo Bekti ◽  
Mardhia Mardhia
Keyword(s):  
Clinical Trials ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Host Cells ◽  
Rapid Transmission ◽  
Adequate Dosage ◽  
Immunogenic Response ◽  
Selection Of

The coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 26 million individuals and caused 871,166 deaths globally. Various countries are racing against time to find a vaccine for controlling the rapid transmission of infection. The selection of antigen targets to trigger an immune response is crucial for vaccine development strategies. The receptor binding domain of the subunit of spike 1 protein is considered a promising vaccine candidate because of its ability to prevent attachment and infection of host cells by stimulating neutralizing antibodies. The vaccine is expected to mount a sufficient immunogenic response to eliminate the virus and store antigenic information in memory cells for long-term protection. Here, we review the ongoing clinical trials for COVID-19 vaccines and discuss the immune responses in patients administered an adequate dosage to prevent COVID-19.

scholarly journals Long-term Coexistence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) with Antibody Response in Coronavirus Disease 2019 (COVID-19) Patients

2020 ◽  
Author(s):  
Bin Wang ◽  
Li Wang ◽  
Xianggen Kong ◽  
Jin Geng ◽  
Di Xiao ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Adaptive Immunity ◽  
Clinical Symptoms ◽  
Igg Antibodies ◽  
Innate And Adaptive Immunity ◽  
Adaptive Immune ◽  
Specific Igg ◽  
Specific Igg Antibodies

AbstractSevere acute respiratory syndrome coronavirus 2 infection causing coronavirus disease 2019 has spread worldwide. Whether antibodies are important for the adaptive immune responses against SARS-CoV-2 infection needs to be determined. Here, 26 cases of COVID-19 in Jinan, China, were examined and shown to be mild or with common clinical symptoms and no cases of severe symptoms were found among these patients. A striking feature of some patients is that SARS-CoV-2 could exist in patients who have virus-specific IgG antibodies for a very long period, with two cases for up to 50 days. One COVID-19 patient who did not produce any SARS-CoV-2-bound IgG successfully cleared SARS-CoV-2 after 46 days of illness, revealing that without antibody-mediated adaptive immunity, innate immunity may still be powerful enough to eliminate SARS-CoV-2. Overall, this report may provide a basis for further analysis of both innate and adaptive immunity in SARS-CoV-2 clearance, especially in non-severe cases. This study also has implications for understanding the pathogenesis and treatment of SARS-CoV-2.

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