Recombinant vaccines and the development of new vaccine strategies

Abstract

Vaccines were initially developed on an empirical basis, relying mostly on attenuation or inactivation of pathogens. Advances in immunology, molecular biology, biochemistry, genomics, and proteomics have added new perspectives to the vaccinology field. The use of recombinant proteins allows the targeting of immune responses focused against few protective antigens. There are a variety of expression systems with different advantages, allowing the production of large quantities of proteins depending on the required characteristics. Live recombinant bacteria or viral vectors effectively stimulate the immune system as in natural infections and have intrinsic adjuvant properties. DNA vaccines, which consist of non-replicating plasmids, can induce strong long-term cellular immune responses. Prime-boost strategies combine different antigen delivery systems to broaden the immune response. In general, all of these strategies have shown advantages and disadvantages, and their use will depend on the knowledge of the mechanisms of infection of the target pathogen and of the immune response required for protection. In this review, we discuss some of the major breakthroughs that have been achieved using recombinant vaccine technologies, as well as new approaches and strategies for vaccine development, including potential shortcomings and risks.

An Overview of History, Evolution, and Manufacturing of Various Generations of Vaccines

“…In order to make recombinant hepatitis B vaccine, recombinant HBsAg is ex-pressed in cells that have a powerful expression system (such as yeast) leading to the production of virus-like particles by HBsAgs, which are highly immunogenic. Since these particles have no genome, they do not create disease and lead to effective and powerful response against the main pathogen (46,47). Other kinds of common vaccines are anti-herpes simplex virus, anti-rotavirus, and anti-HPV vaccines.…”

Optimization of recombinant vaccine antigen dose in mouse model by ELISA and immunophenotyping

“…The antigenic part in the pathogens is responsible for inducing host immune response against pathogens and developing sufficient immunity against the pathogenic antigen is the superior goal for vaccine development. The success of vaccines primarily depends on the ability of antigens producing antibodymediated immunity whereas, managing cell-mediated immunity is important against intracellular organisms [1]. The choice of antigens is determined by their immunological efficacy and safety with or without the use of adjuvants [2].…”

Microparticle Vaccines Against Toxoplasma gondii

“…Most modern vaccines based on subunits of pathogens, such as purified proteins, are likely to be less immunogenic than traditional vaccine antigens and are often unable to initiate a strong immune response [9]. These subunit vaccines require effective adjuvants to aid them to elicit strong protective immune responses [10,11].…”

“…These subunit vaccines require effective adjuvants to aid them to elicit strong protective immune responses [10,11]. Therefore, one of the current important issues in vaccinology is the urgent need for the development of new or improved adjuvants to enhance the immunogenicity or effectiveness of vaccines [9,10,12]. Different adjuvants capable of improving immunity and protection have been described in numerous studies [9,10,12].…”

“…Therefore, one of the current important issues in vaccinology is the urgent need for the development of new or improved adjuvants to enhance the immunogenicity or effectiveness of vaccines [9,10,12]. Different adjuvants capable of improving immunity and protection have been described in numerous studies [9,10,12]. However, the safety concern of an adjuvant is still a crucial issue to limit adjuvant development [13].…”