Phase II clinical trial of Soberana Plus in convalescents will have two stages

HAVANA, Cuba, Apr 16 (ACN) The phase II clinical trial of the Soberana Plus vaccine candidate in convalescents will be divided into two stages, explained Dr. Arturo Chang Monteagudo, principal investigator of the study at the Institute of Hematology and Immunology.

The expert explained that the process will have a phase II A and then a II B, to cover a total of 450 subjects.

In the first phase, 20 convalescent patients between 60 and 80 years of age will participate in order to evaluate the safety of the product in this age group, not included in the Phase I clinical trial.

He said that later, and depending on the results of the first stage, they will work with 430 individuals, of whom 86 will receive a placebo -a formulation similar to the vaccine but without the vaccine antigen-, in order to really test the effect of the drug.

The prospects with this vaccine candidate, unique in the world for the care of convalescents, are to protect those who have recovered from the disease with a low immune level, and to use it as a booster dose for other vaccines, said the researcher.

He added that it also makes possible the production of the Cuban anti-Sars-CoV-2 globulin range, in which the antibodies of COVID-19 convalescents with immunity strengthened by Soberana Plus are purified, in order to protect patients in serious and critical condition, as an alternative to direct plasma transfusion.

Soberana Plus, developed by the Finlay Vaccine Institute (IFV), was designed because of evidence, since the beginning of the pandemic, that those infected with the new coronavirus could eventually decrease their protective antibodies and become reinfected, said Chang Monteagudo.

He said that in the country this phenomenon was detected thanks to the investigations of the National Blood Program, in plasma donors for the treatment of other patients with COVID-19, and by the population study conducted by the National Center of Medical Genetics.

This vaccine candidate, he continued, was created to have antigenic simplicity and only elicit specific antibodies against one part of the virus, which leads to its binding to the recipient in the human cell.

He added that it was based on a platform similar to that of Soberana 01 and 02, but specifically with a view to awakening memory clones in the organism and improving immunogenicity against the pathogen.

The doctor stated that the current phase has been reached after successfully passing through a first clinical trial, in which the safety of the drug was demonstrated in a primary manner in 30 convalescents with low immune levels.

In addition, only local adverse events were reported, none of them serious, and it was proven that a single dose is highly effective, since the vaccinated patients increased their protective neutralizing antibodies up to four times, and some increased up to 20 times those initially presented, he added.

In recent days, Rolando Ochoa Azze, Researcher and Professor at the IFV, warned that even those who receive Soberana Plus should continue to be careful, since in the case of COVID-19 it will be necessary to vaccinate around 80 or 90 percent of the population to be able to speak of herd immunity, and this will only be possible with mass vaccination.