Home Men's Health Analysis of immunogenicity-induced DNA vaccines in opposition to totally different SARS-CoV-2 variants

Analysis of immunogenicity-induced DNA vaccines in opposition to totally different SARS-CoV-2 variants

Analysis of immunogenicity-induced DNA vaccines in opposition to totally different SARS-CoV-2 variants


In a latest article printed in PLOS ONE, researchers designed 5 deoxyribonucleic acid (DNA) vaccine candidates based mostly on totally different extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains. They evaluated the immunogenicity of every in mice.

Study: Evaluation of immunogenicity-induced DNA vaccines against different SARS-CoV-2 variants. Image Credit: M-Foto/Shutterstock.comExamine: Analysis of immunogenicity-induced DNA vaccines in opposition to totally different SARS-CoV-2 variants. Picture Credit score: M-Foto/Shutterstock.com


A protected and efficient vaccination technique is the important thing to combating SARS-CoV-2, the virus that brought on the coronavirus illness 2019 (COVID-19) pandemic, which led to worldwide lockdowns, socioeconomic disruption, and an unprecedented risk to public well being. 

Previously, heterologous vaccination methods have efficiently combated many lethal illnesses, equivalent to malaria, influenza, and human papillomavirus.

Research have proven that totally different vaccine platforms, equivalent to DNA, adenoviral vectors, modified vaccinia Ankara viral vectors, and recombinant subunit vaccines, considerably enhance humoral and mobile immunity.

Of their earlier research, researchers discovered DNA vaccine candidates protected, secure (at room temperature), and extra handy to retailer and ship than different vaccine platforms; thus, they appear apt for emergencies just like the one induced by the COVID-19 pandemic. 

DNA vaccines additionally elicit sturdy humoral and mobile immune responses. Nonetheless, they typically don’t induce vital medical advantages.

In regards to the research

Given the confirmed advantages of homologous and heterologous vaccination in opposition to SARS-CoV-2, researchers examined the effectiveness of a prime-boost routine of 5 DNA vaccines they developed in opposition to SARS-CoV-2 in a mouse mannequin.

These newly developed vaccine candidates had been based mostly on the primary genotype spike (S), which incorporates the Wuhan pressure, the primary ever SARS-CoV-2 pressure remoted in Korea, and the Alpha, Beta, Gamma, and Delta variants, that are categorised as SARS-CoV-2 variants of concern (VOCs) by the World Well being Group (WHO). 

They intramuscularly (i.m) vaccinated mice with these DNA vaccine candidates to evaluate their immunogenicity based mostly on elicited mobile and humoral immune responses.

For humoral immunogenicity analysis, they drew the blood of vaccinated mice one week after the final vaccination dose. The sera of vaccinated take a look at animals had been analyzed for SARS-CoV-2 particular whole immunoglobulin G (IgG) and its subtypes utilizing enzyme-linked immunosorbent assay (ELISA).

Then, they calculated the whole IgG titers as half maximal efficient focus (EC50) whereas figuring out P-values utilizing one-way ANOVA with Fisher’s LSD take a look at. In addition they calculated the ratios of IgG2b and IgG2c to IgG1.

Moreover, they used a plaque discount neutralization take a look at (PRNT) to investigate neutralizing antibody (nAb) ranges within the sera of the vaccinated animals; additional, they discovered P-values utilizing a two-way evaluation of variance (ANOVA) with Tukey’s take a look at.

A surrogate virus neutralization take a look at (sVNT) helped take a look at mice sera for his or her neutralization fee, the place p-values had been decided utilizing one-way ANOVA with Dunnett’s take a look at.

Moreover, the researchers evaluated cell-mediated immune responses elicited in response to all 5 DNA vaccine candidates per week after the final vaccination.

To this finish, they collected mice splenocytes and examined them utilizing a spike glycoprotein peptide pool in opposition to unstimulated cells. 

To judge cross-vaccination immunogenicity, the researchers autopsied mice one week after the ultimate vaccination; additional, they remoted their splenocytes to measure the degrees of secreted cytokines utilizing ELISpot in comparison with the unstimulated group.


The authors famous that the mice vaccinated with DNA vaccine candidates based mostly on the S genotype, Alpha, and Beta variants had greater nAb and whole IgG ranges than the others.

Exceptionally, the Alpha variant-based vaccine candidate elicited a robust and numerous cytokine response.

Moreover, splenocytes of all take a look at mice confirmed excessive ranges of cytokines, equivalent to interleukin-6 (IL-6), IL-13, and interferon-gamma (IFN-γ), whereas the Alpha variant-based DNA vaccine additionally elicited extra tumor necrosis factor-α (TNF-α) ranges.

In mice vaccinated with homologous vaccination based mostly on Alpha VOC, greater ranges of IL-6 and IL-13 had been related to decreased angiotensin-converting enzyme-2 (ACE2) expression and elevated SARS-CoV-2 entry by way of the nasal and bronchial epithelium. As well as, these mice displayed elevated TNF-α ranges than the opposite teams.

Moreover, mice vaccinated with S/S and S/Alpha confirmed markedly elevated ranges of T helper cells (Th1) and Th2-secreted cytokines, IFN-γ, and IL-6/13, suggesting that DNA vaccine candidates drive sturdy T cell responses by balancing cytokine ranges.


Total, the research outcomes recommended that the efficacy of DNA vaccine candidates was variant-dependent, with vaccines based mostly on the S and Alpha variants enhancing greater immune responses than the opposite vaccines.

The outcomes, nonetheless, remained the identical no matter boosting with heterologous or homologous vaccines.

Thus, whether or not receiving a homo- or heterologous routine, recipients of those vaccines require prolonging the elicited immune response (by booster vaccination) to realize sufficient protecting efficacy in opposition to SARS-CoV-2.

Additional analysis ought to determine which vaccination methods are optimum for long-term immunity and which T resident reminiscence cells contribute most to confer safety in opposition to SARS-CoV-2.



Please enter your comment!
Please enter your name here