By Dr Michael Head, PhD, University of Southampton — The Conversation, 7 December 2021
The western world has written plenty about its high-profile COVID vaccines: the mRNA products of Pfizer and Moderna, viral-vectored jabs from AstraZeneca and Johnson & Johnson. But not Cuba. It has been quietly working on its own vaccines, immunising its population and selling doses abroad.
Cuba’s vaccine efforts have maintained a relatively low profile in the west, partly due to politics — the US embargo against Cuba that began in the cold war is still in effect. But for those familiar with Cuba, its COVID vaccine development should come as no surprise. The country has a long history of manufacturing its own vaccines and medicines. Two of its COVID vaccines — Abdala and Soberana 02 — appear to have performed very well in trials.
Abdala is a protein subunit vaccine, a well-established design also used by the hepatitis B vaccine and Novavax. These vaccines work by delivering just a portion of the virus — in the case of Abdala, bits of the coronavirus’s spike proteins — grown in engineered yeast cells. The other Cuban vaccine, Soberana 02, uses a “conjugate” design, containing a different part of the spike protein and generating an immune response by attaching it to a harmless extract from the tetanus toxin. A booster dose known as “Soberana Plus” was later identified as beneficial.
On 1 November 2021, a preprint of a Soberana phase 3 trial including 44,031 participants suggested that two doses of Soberana 02 with a Soberana Plus booster are together 92% protective against symptomatic COVID. For Abdala, Cuban press releases from June and July 2021 reported the three-dose schedule is also reportedly 92% protective against symptomatic COVID and allegedly fully protective against severe disease and death. Around 90% of Cuba’s 11 million people have received at least one dose, with 82% considered fully vaccinated — among the best COVID vaccine coverage in the world. Cuba has submitted both vaccines to the WHO for approval, which would improve the likelihood of them being used abroad. This article has been republished under Creative Commons licence.