In 2016, Dr. Egorov and his co-authors filed a patent describing an innovative vector structure that, in addition to a moderate defect in the NS1 gene, replaces the NEP gene with a heterologous analogue from another subtype of the influenza A virus. This genomic editing principle produces highly attenuated influenza vectors, which surpass cold-adapted live influenza vaccine (LAIV) strains in safety. Moreover, these recombinant viruses are highly immunogenic and capable of achieving high titers in embryonated chicken eggs and Vero cells. The universal influenza vaccine candidate UNIFLUVEC successfully completed phase 1 clinical trials, exhibiting a replication-deficient phenotype at high vaccine doses in adult volunteers (NCT04650971).

 

At the same time, incomplete deletion of the NS1 gene allows the production of the vector to extremely high titers in 10-day-old embryonated chicken eggs. The vaccine can be produced in standard influenza vaccine production facilities.  A simple purification method has been developed using only tangential filtration. The composition of the drug product has been developed, ensuring the stability of the drug at +4°C.