Cuba’s bet on homegrown COVID vaccine is rewarding

When the COVID-19 pandemic began, Cuba decided not to wait elsewhere in the world to develop a vaccine. Researchers and officials know that US economic sanctions against countries that prevent US-made products from being exported there will make it difficult for Cuba to obtain vaccines and cures. Was there. Vicente Vérez Bencomo, director of the Finley Vaccine Institute in Havana, said:

Therefore, the Finlay Institute and other state-owned biotechnology centers in Cuba Started development of original COVID-19 vaccine Expecting at least one of them to be effective.Their bet seems to be rewarding: in the November 6th preprint published on medRxiv¹, Vérez Bencomo and his colleagues found that one of the laboratory’s vaccines, Soberana 02, is more than 90% effective in protecting against symptomatic COVID-19 infections when used in combination with related vaccines. I am reporting. Importantly, this combination causes a surge in hospitalizations and deaths worldwide and is an infectious delta variant of the coronavirus SARS-CoV-2, which currently accounts for almost all COVID-19 cases in Cuba. Seems to be effective against.

As of November 18, 89% of the Cuban population (including children under the age of 2) has another Cuban vaccine called Soberana 02 or Abdala manufactured at the Center for Genetic Engineering and Biotechnology (CIGB) in Havana. Is inoculated at least once. ..Center Reported in July The triple-dose vaccine, Abdala, was more than 92% effective in a phase III trial involving more than 48,000 participants, but full results have not yet been published.

Cuban regulators approved the use of 02 shots of Abdullah and Soberana in adults in July and August, respectively, and healthcare professionals began immunizing children with both vaccines months later. The country has begun exporting two homemade vaccines to Venezuela, Vietnam, Iran and Nicaragua. We are also seeking vaccine approval from the World Health Organization. This is an important step in making vaccines available throughout developing countries.

Major progress

In developing Soberana 02, Vérez Bencomo’s group leveraged existing “conjugated” vaccine technology. Finlay’s conjugated vaccine takes a protein or sugar from a bacterium or virus and chemically binds it to a harmless fragment of a neurotoxic protein from a tetanus bacterium. This combination elicits a stronger immune response than either component alone. Conjugate vaccines against meningitis and typhoid fever are used worldwide, and Cuba has been immunizing children with this type of vaccine for many years.

Vérez Bencomo’s team has tetanus toxin protein SARS-CoV-2 spike protein (the spike protein enters the cell that helps the virus). After more than 14,000 people were vaccinated twice in a phase III trial, the risk of recipient symptomatic COVID-19 was reduced by 71% compared to the placebo group of the same size. This is Johnson & Johnson (J & J) in New Brunswick, NJ, and AstraZeneca in Cambridge, England.

To improve this protection, the Finlay team also gave participants a third shot. Researchers have previously tested a jab called Soberana Plus against people who are already ill with COVID-19 and found that it improves the immune response.².. So they gave Soberana Plus, which is based solely on the RBD protein, to another set of 14,000 participants who had already received two Soberana 02 doses, with a third dose increasing overall efficacy to 92.4%. I found that I would do it.

Vérez Bencomo states that the Finlay Institute can produce 10 million Soberana 02s a month. To further test the vaccine, he and his colleagues will partner with the Pasteur Institute in Tehran to conduct a similar 24,000 trial in Iran and announce their results shortly.

The CIGB Abdala vaccine has also made great strides. Similar to Soberana 02, the technology behind it applies the existing vaccine developed by Cuba and used for many years (vaccine for hepatitis B). Researchers manipulated yeast cells to produce parts of the RBD that differed from those used in Soberana 02 and purified the protein for use in Abdala. CIGB researcher Merardo Pujol Ferrer says that 24 million doses have been given to 8 million people in Cuba, providing researchers with a large dataset to track their safety and efficacy. .. He says the team plans to release the data later this month.

Extended Toolbox

Protein-based vaccines such as Soberana 02 and Abdala There may be some advantages over other types of vaccinesCraig Laferrière, Head of Vaccine Development at Novature Ventures in Toronto, Canada, says he is comparing the safety and efficacy of COVID-19 jabs. Unlike messenger RNA (mRNA) vaccines manufactured by New York City-based Pfizer and Cambridge-based Moderna, Mashsets, protein vaccines do not need to be kept at cryogenic temperatures, making them easy to deliver to remote locations.

It may also have fewer side effects than AstraZeneca or J & J vaccines that use adenovirus to deliver genes for different parts of RBD to cells. Linked to a blood clot.. Finlay’s medRxiv manuscript (not peer-reviewed) does not contain extensive clinical data, but Laferrière says that the side effects of Soberana 02 are minimized because less than 1% of participants in Phase III trials had a fever. I’m expecting it. Veréz-Bencomo states that more data will be released shortly.

However, Laferrière adds that this approach also has its drawbacks. Protein-based vaccines are made by synthesizing protein clumps using different types of cells. Soberana 02 is produced in hamster ovarian cells. This takes longer than some other methods for producing this type of vaccine.And the evidence suggests³ Conjugate vaccines using the tetanus toxin protein are ineffective for those who have already received another vaccine of this type, such as the pediatric meningitis vaccine.

Vérez Bencomo states that he is confident in the safety of the vaccine, primarily because conjugate vaccine technology has been used without major problems for decades. The Finlay team has worked together to create a vaccine for children, but they were also well aware of the dosage and side effects to jump into the Soberana 02 pediatric trial that began in June. Nearly two million children have been vaccinated in Cuba so far, and Vérez Bencomo says unpublished data suggests that the vaccine is safe and effective.

John Grabenstein, president of Vaccine Dynamics, a vaccine consultancy in Easton, Maryland, said: “Everyone is using another tool from the toolbox and almost everything is working.” Soberana 02’s data looks solid, but how long the immunity given by the vaccine lasts. He says it takes time to make a decision.

Meanwhile, Cuba is pursuing a COVID-19 vaccine development strategy. Finlay’s Soberana 01, which associates peplomer with the sugar of the bacterium that causes meningitis rather than tetanus toxin protein, and Mambisa, a nasal vaccine containing the same RBD fragment used in Abdala, are still in clinical trials. is. ..