To halt the spread of COVID-19, several vaccines are under clinical trials. But, only a few of them have reached the level of approval, which included Pfizer and BioNtech’s vaccine. So now, it seems like several other vaccinations are making their way to be there in the market to save humanity.
For this purpose, a new vaccine is planning to be here. But, for now, it has just cleared its initial levels. Ad26.COV2.S is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike protein. Ad26 vector has been the key element in vaccination against the Ebola Virus.
The study on Adenovirus Serotype 26 vector, published by The New England Journal of Medicine this Wednesday. The study showed the results of its initial trial, i.e., phase 1 to 2a.
The trial started on June 22, 2020, at multiple centers in Belgium and the US. The study design was placebo. The trial included two groups of healthy adults. The first group, which had individuals between the ages of 18 and 55, was named Cohort 1. The second group, which had 65 years or older, was named Cohort 3.
Both the cohorts received either a low dose comprised of 5×10^10 viral particles or a high dosage of 1×10^11 viral particles per mm.
After the IM administration of Ad26 vector-based shots, volunteers faced fatigue, headache, myalgia, and injection-site pain. Among these effects, the most frequent one was fever.
Although the participants from both cohorts experienced them, individuals from cohort 3 were less affected. Similarly, those with low dosages exhibited less systemic adverse events.
Result Of Trial
Now, let’s discuss the trial part we have been patiently waiting for a long time. Yes, the effect of the vaccine. According to the study, after the 29th day of the first dosage, approximately 90% of individuals developed neutralizing antibody titers. This stat reached up to 100% by the 57th day of administration which remained stable at least by 71. The second dose increased the titer by 0.3, i.e., from 2.6 to 2.9.
Other than the neutralizing antibody titers, helper T cells were also detected. On the 14th day of the trial, 76 to 83% of cohort 1 and 60 to 67% of people from cohort 3 developed CD4+T cells. CD8+T cells were also there in both cohorts but to a lesser extent in the 3rd one.
To conclude, the Ad26.COV2-S vaccine seems safe to produce an immune response against SARS-CoV-2. This vaccine is proving to be among the best COVID-19 Vaccines.