COVID-19: All you need to know about Cuba's 3-dose conjugate vaccine Soberana 2

As per the Cuban government’s COVID-19 task force, the two doses of Soberna 2 are to be followed by a booster shot of Soberana Plus, taken 28 and 56 days after the first dose.

Soberana 2, developed by the Finlay Institute, the Centre for Molecular Immunology and the National Biopreparations Centre, is one of the three vaccines in the Soberana series.

It is the only conjugate vaccine developed so far against the Coronavirus. It combines a weak antigen along with a strong antigen that helps the immune system in producing a stronger response to the weak antigen.

“Soberana 2 is unique amongst COVID vaccines for another reason: it combines the antigen's receptor-binding domain with a deactivated form of tetanus in order to boost immune response, making it the only existing conjugate vaccine for COVID-19,” said Helen Yaffe, lecturer at the University of Glasgow, in a blogpost.

Soberana 2 consists of a protein that is derived from the virus, which binds to the cells of the human body, triggering a response. It can be stored in regular refrigeration settings of 2 to 8 degree Celsius.

Apart from Soberana 2, Cuba is developing four other vaccines in its fight against COVID-19. Reports suggest that several countries like Iran, Argentina and Vietnam have expressed interest in manufacturing Cuban vaccines, while Mexico and Jamaica are interested in buying them.