Cuban researchers are upgrading the island’s homegrown coronavirus vaccines to ensure protection against the new Omicron variant.
Vicente Verez, director of Cuba’s Finlay Institute for Vaccines, said this week that it was clear the country’s Soberana-02 vaccine would continue to provide “a certain level of protection” against Omicron, but added the extent of that protection was still uncertain.
“We decided as of last week to start developing a Soberana Plus variant having the Omicron RBD protein,” Verez said on Tuesday, referring to the receptor-binding domain (RBD), a key part of the virus located on its “spike”.
“We have already started it, and that protein is being built at the moment.”
In November, Verez said the Finlay Institute can produce 10 million Soberana doses per month, the journal Nature reported.
More than 81 percent of Cuba’s population of 11 million is fully vaccinated, according to data from Johns Hopkins University.
Some global vaccine manufacturers, including BioNTech, have expressed guarded confidence that their vaccines would offer strong protection against Omicron, which was designated a “variant of concern” by the World Health Organization (WHO) last week.
Others, such as Moderna, have raised the prospect of a material drop in protection.
It is not yet clear whether Omicron is more transmissible than other variants, or if it causes more severe disease.
Cuba has been under a US trade embargo for years. At the beginning of the pandemic, officials worried they would not be able to access Western vaccines due to the trade sanctions, so they set about producing their own.
Cuba has developed an unusually large biotech sector for a country its size. It has made vaccines available to several of its allies, including Vietnam, Venezuela, Nicaragua and Iran.
Soberana-02 is more than 90 percent effective in preventing symptomatic COVID-19 infection, when used in combination with a related vaccine, according to a preprint study published by the research portal medRxiv1 in November. That study was done before the arrival of Omicron.
In developing Soberana-02, Verez’s institute drew on its existing conjugate vaccine technology. This involves taking a protein or sugar from a virus then chemically linking it to a harmless fragment of a neurotoxin protein from the tetanus bacterium, Nature reported.
“The combination elicits a stronger immune response than either component alone. Conjugate vaccines against meningitis and typhoid are used around the world, and Cuba has been immunizing children with a vaccine of this type for years,” according to data cited by the journal.
Abdala, a three-dose Cuban vaccine, has been shown to be more than 92 percent effective in trials that included more than 48,000 participants, but the full results have not yet been published, according to the data.
Critics have accused Cuba’s government and researchers of not being transparent with their vaccine efficacy data.
Cuba hopes to extend exports of its locally developed vaccines, and has asked the World Health Organization (WHO) to approve them, which many countries require before importing vaccines.
In mid-September, Havana launched a vaccination campaign for children aged between two and 10 years old, making it one of the first nations to approve vaccines for that age group.
Cuba has yet to detect the Omicron variant, but earlier this week announced it would tighten restrictions beginning December 4 on passengers from some African countries.