Cuba developed world's first conjugate vaccine: All you need to know
Of late, Cuba developed the world's first conjugate vaccine for COVID-19, Soberana 2 (Sovereign). On 9 July 2021, BioFarma, Cuba’s State-run corporation, announced that its indigenously produced Soberana 2 vaccine was 91.2% efficacious in Phase-3 trials.
Soon after the announcement of the results, Cuban President Miguel Díaz-Canel thanked the scientists of the island nation who were working on the vaccine.
Felices y buenos días, #Cuba. Tuyo es el éxito de #Soberana02 y de #Abdala. Hace 13 meses, pedí a nuestros científicos una respuesta soberana contra la #COVID19. No dieron una sino cinco respuestas. Dos ya son vacunas y vamos por más. #CubaSalvaVidas pic.twitter.com/GusRrIRDOc— Miguel Díaz-Canel Bermúdez (@DiazCanelB) June 22, 2021
1- Soberana 2 is one of the three vaccines in the Soberana series. When delivered with a booster shot of Soberana Plus is 91% efficacious against symptomatic COVID-19 cases.
2- It is developed by Finlay Institute in collaboration with the Centre for Molecular Immunology and National Biopreparations Centre.
3- If approved, Cuba will become the first Latin American country to manufacture and produce vaccines against Covid-19.
4- It is the only conjugate vaccine that combines the virus’ receptor-binding domain with a deactivated form of tetanus to boost the immune response.
5- Another of its vaccines, Abdala has shown efficacy of 92.8% in late-stage trials.
How is Soberana 2 vaccine administered?
Unlike Pfizer-BioNTech and Moderna vaccines, both Soberana and Abdala are three shot vaccines. Soberana 2 vaccine is administered in a three-dose regimen-- two shots of Soberana 2 and one shot of Soberana Plus. It is administered with a 0-28-56 day regimen.
Conjugate vaccines combine weak antigen with strong antigen as a carrier. This triggers a strong immune response to the weak antigen. These are used to prevent disease by building an immune response to antigens recognised by the immune system. Examples of conjugate vaccines are Haemophilus influenza type b and the pneumococcal bacteria.
The design and manufacturing allow the vaccine to be stored in regular refrigeration settings of 2–8 degrees Celsius. They have an excellent safety record and have been associated with a few serious adverse effects following immunization after more than 20 years.
The experts are of the view that conjugate-vaccines have been used against bacteria and not viruses.
Advantages of Conjugate Vaccines
1- Improved immune and memory response
2- Long-lasting protection
3- Effect on bacterial carriage
4- Creation of herd immunity
5- Protection to infants and toddlers
Both Soberana and Abdala are subunit vaccines. This means that a part of the virus forms the antigen and is hitched on to another construct.
In Abdala, the protein of the coronavirus is combined with a chemically manufactured adjuvant while in Soberana 2, the spike protein is chemically linked to the tetanus toxoid, making it a conjugate vaccine.
Vaccines in Cuba: Production and Development
Cuba produces 60-70% of medicines that are consumed domestically and vaccinates against 13 diseases with 11 vaccines. Of these 11 vaccines, 8 vaccines are produced in Cuba.
Apart from Soberana 2, four other vaccines are underway in Cuba. All five vaccines are protein vaccines. These vaccines are made up of a protein derived from the virus, which then binds to human cells to trigger an immune response.
Protests in Cuba
The island nations reported a surge in COVID-19 cases and deaths in 2021 with a record 6,900 cases and 47 deaths so far.
The Cubans are protesting against the mishandling of the pandemic by the authorities, shortage of vaccines and collapse of the economy. The citizens are demanding a faster vaccination programme after a sudden surge and increase in death rates.
As per media reports, Iran, Argentina, and Vietnam have shown interest in manufacturing the Cuban vaccines while Mexico and Jamaica have shown interest in buying them.