Clinical study with Mambisa in convalescents: Antibody titers increased at least fourfold in most subjects
The preliminary results of the clinical study in convalescents with the vaccine candidate Mambisa were presented on Wednesday at the BioHabana 2022 congress.
Dr. Gerardo Guillén Nieto, director of Biomedical Research at the Center for Genetic Engineering and Biotechnology (CIGB), reported that the study included 1,041 convalescent volunteers with at least two months of recovery and up to more than a year and a half of having contracted the disease.
It had two research arms: one where half of the sample received the Abdala vaccine, and the other half a single booster dose of the Mambisa vaccine candidate.
“Almost all the samples have already been evaluated, only a few are missing, but with the results we have we can report that the success criteria of the study are met: more than 70% of the volunteers had at least a four-fold increase in antibody titers, or 20% in the inhibitory capacity of these antibodies, that is, of their functionality”, he specified.
He referred that at least 80% of the volunteers already reach these response levels and there are dozens of other volunteers, 83 samples evaluated to date, who do not meet that criteria, but it is not because they do not respond to the immunogen, but rather because they already have more of 90% inhibitory capacity and therefore cannot increase 20% more.
Of the samples evaluated, 96% have a high level of protection and have received a benefit from the vaccine, the scientist specified.
According to Guillén Nieto, given the circulation of new variants, this booster dose is very important to guarantee protection against the virus and its mutations, “but it also allows a selection of memory clones, which are high-affinity clones that guarantee long-term protection. It is one of its advantages”.
He referred that at least 80% of the volunteers already reach these response levels and there are dozens of other volunteers, 83 samples evaluated to date, who do not meet that criteria, but it is not because they do not respond to the immunogen, but rather because they already have more than 90% inhibitory capacity and therefore cannot increase 20% more.
Of the samples evaluated, 96% have a high level of protection and have received a benefit from the vaccine, the scientist specified.
According to Guillén Nieto, given the circulation of new variants, this booster dose is very important to guarantee protection against the virus and its mutations, “but it also allows a selection of memory clones, which are high-affinity clones that guarantee long-term protection.It is one of its advantages”.
Currently, there are 349 vaccine candidates in the world, of which 38 have emergency use authorization, and only 13 are administered nasally. The latter, all in early stages of clinical evaluation, making Mambisa one of the potential immunogens at the forefront of clinical development.
