Taming the Enemy
Norman Begg in The Remarkable Story of Vaccines, 2023
DNA vaccines contain the genetic material that has the code for the antigen of the vaccine, the part that stimulates an immune response. A DNA vaccine is either inserted into the gene of a harmless virus before injection or injected directly. Vaccines that use a harmless virus as the carrier for the genetic material are called viral vector vaccines. The genetic material for the virus is inserted into the harmless virus, which acts as a vector (the medical term for a carrier). The viral vector may sometimes replicate, but does not cause disease. Several of the COVID-19 vaccines are viral vector vaccines, including the one developed at Oxford University with AstraZeneca, the Johnson & Johnson vaccine, and my favourite – simply because of its name – Sputnik V. These COVID-19 vaccines use an adenovirus, one of the causes of the common cold, as the vector to carry the genetic information in the vaccine. A useful feature of viral vector vaccines is that the same vector can be used to make different vaccines. The adenovirus vector that is used for Johnson & Johnson’s COVID-19 vaccine had already been used to make a highly effective Ebola vaccine a few years earlier.
Comparative aspects of the tick–host relationship: immunobiology, genomics and proteomics
G. F. Wiegertjes, G. Flik in Host-Parasite Interactions, 2004
As mentioned above, research efforts have been directed toward development of recombinant vaccines and different types of tick antigens have been selected as potential candidates. Unfortunately, most attempts to induce protective immunity against tick infestation have met with limited success (Mulenga et al., 2000). Recently, the use of DNA or gene-based immunization strategies is being considered as a more efficient approach to vaccine development and immunotherapy (Thalhamer et al., 2001). DNA vaccines consist of plasmid DNA carrying genetic material encoding an antigen whose expression within the cells is under control of eucaryotic promoters (Srivastava and Liu, 2003). Important advantages of DNA vaccines over classic vaccines include their ability to induce both humoral and cellular immune responses in a range of hosts and the potential to enhance their immunogenicity by co-expression of other immunomodulatory proteins (Sharma and Khuller, 2001; Thalhamer et al., 2001). Although successful induction of protective responses using genetic immunization has been demonstrated for a number of viral, protozoan and bacterial pathogens (Srivastava and Liu, 2003), there are only a handful of reports describing the use of DNA vaccination to induce immune responses against haematophagous vectors of disease (De Rose et al., 1999; Foy et al., 2003). Nevertheless, DNA vaccines represent an alternative strategy with enormous potential as a research tool, which may translate into faster and more efficient screening of vector antigen targets.
The Utility of Immunoglobulin Fusions in DNA Immunization
Maurizio Zanetti, J. Donald Capra in The Antibodies, 2002
The targeted DNA vaccine against influenza, CTLA4-Ig-HA generated higher Ab levels (p 0.001; Mann-Whitney) and protected mice by reducing viral titers 100-fold (p 0.0004; Mann-Whitney; Figure 4) compared with the untar-geted vaccine. As the CTL responses were not different, this difference in protection was probably Ab based. Incidentally, Ab levels and protection afforded by the targeted vaccine was not significantly different from that afforded by the protein-based commercial split vaccine (Figure 4). However, that this comparison is not germane, because the latter contains neuraminidase components in addition to HA. Moreover, as outlined in the introduction, our strategy aims to improve on currently investigated DNA vaccine strategies through targeting so that they could be used, for example, where no current vaccine exists, rather than as a replacement for effective protein-based (or for that matter live virus) vaccines.
Immune response induced in rodents by anti-CoVid19 plasmid DNA vaccine via pyro-drive jet injector inoculation
Published in Immunological Medicine, 2022
Tomoyuki Nishikawa, Chin Yang Chang, Jiayu A. Tai, Hiroki Hayashi, Jiao Sun, Shiho Torii, Chikako Ono, Yoshiharu Matsuura, Ryoko Ide, Junichi Mineno, Miwa Sasai, Masahiro Yamamoto, Hironori Nakagami, Kunihiko Yamashita
The coronavirus disease 2019 (COVID-19) pandemic has greatly necessitated the development of a safe and effective vaccine against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Various vaccine candidates were tested in clinical studies, and several varieties of vaccine platforms have been used. These include protein subunits, replicating viral vectors, non-replicating viral vectors, inactivated viruses, RNA, DNA, live attenuated viruses, and virus-like particles (VLPs). Plasmid DNA [1] and mRNA [2] vaccines have been developed in addition to traditional vaccines because they can be produced quickly by generic manufacturing and are constructed directly from genetic sequence information. Therefore, nucleotide-based vaccines can easily adapt to viral mutations [1]. Furthermore, mass production technology has been established for DNA plasmids. Similarly, new technologies, such as mRNA-stabilizing technology, are being developed for mRNA vaccines [2]. Five mRNA vaccine candidates and four DNA vaccine candidates were involved in the development of a vaccine against SARS-CoV-2. However, a major limitation is the lack of an effective method for introducing these molecules (especially DNA plasmids) into cells for effective protein expression and antibody induction. To resolve this issue, we previously reported the potential of the intradermal jet injection method for DNA vaccination using a model DNA vaccination with an ovalbumin expression plasmid [3]. Further, when developing a new DNA vaccine, it is also important to assess the health effects to evaluate the efficacy.
Vaccine for a neglected tropical disease Taenia solium cysticercosis: fight for eradication against all odds
Published in Expert Review of Vaccines, 2021
Rimanpreet Kaur, Naina Arora, Suraj S Rawat, Anand Kumar Keshri, Shubha Rani Sharma, Amit Mishra, Gagandeep Singh, Amit Prasad
Vaccination with encoded DNA is a unique mode to immunize the host against infections, as it involves less cost, time, and effort than conventional protein/peptide-based vaccine production. In a DNA vaccine, the encoded antigen in a suitable expression vector is directly injected under the skin, muscles or other suitable tissue of the host. Earlier DNA vaccine has been used against unicellular organisms or bacterial infections only; later on, it was used for multi-cellular pathogens such as helminths or against other multicellular parasitic infections too [59]. The DNA vaccines have their advantages such as we can easily modify the DNA construct to enhance the immunogenicity of the vaccine and as compare to protein vaccines. The downstream purification processes involved with proteins are mostly cumbersome and tedious and need a constant cold chain to keep the efficacy intact, while there is no such necessity for DNA vaccine.
Current development of Zika virus vaccines with special emphasis on virus-like particle technology
Published in Expert Review of Vaccines, 2021
Velasco Cimica, Jose M Galarza, Sujatha Rashid, Timothy T. Stedman
Preclinical data and results from clinical trials of nucleic acid-based vaccines demonstrated a strong induction of neutralizing antibodies and a reassuring safety profile [82]. All nucleic acid vaccines currently being evaluated in clinical trials express the Zika polyprotein prM-E that is cleaved by host proteases into M and E proteins (Table 1). DNA vaccines developed by NIAID include VRC-ZKADNA090-00–VP (VRC5283), a construct of the prM-E amino acid sequence from ZIKV; and VRC-ZKADNA085–00–VP (VRC5288), a construct expressing a prM-E chimera consisting of the ZIKV amino acid sequence with a swapped carboxy-terminal from the JEV encoding a stem-anchor region (98 amino acids) [83,84]. These DNA vaccine candidates were administered by intramuscular (IM) route or a PharmaJet needle-free device. Another DNA vaccine candidate, termed GLS-5700 (GeneOne Life Science), uses the prM-E immunogen and is administered via the intradermal injection route [85,86]. An alternative approach for DNA-immunization was developed using NS1 antigen (Wenzhou Medical University) (Table 2). Comparison between a DNA vaccine expressing NS1 (VRC-NS1), prME (VRC-prME), or a combination of the two demonstrated protection in a murine model. However, the prME antigen elicited a high level of neutralizing antibodies; these were absent in the mice immunized with NS1 [87].
Related Knowledge Centers
- DNA
- Genetic Engineering
- Transfection
- Plasmid
- Antigen
- Vaccine
- Immune Response
- Veterinary Medicine
- Genetic Vaccine
- Protein Biosynthesis