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the limited data available suggests they’re highly effective

Creator : Michael Head, Senior Analysis Fellow in International Well being, College of Southampton

The western world has written a lot about its high-profile COVID vaccines: the mRNA merchandise of Pfizer and Moderna, viral-vectored jabs from AstraZeneca and Johnson & Johnson, and people which can be simply rising, equivalent to Novavax’s protein-based vaccine. Many nations are counting on them for cover.

However not Cuba. It’s been quietly working by itself vaccines, immunising its inhabitants and promoting doses overseas.

Cuba’s vaccine efforts have maintained a comparatively low profile within the west thus far. Politics could be a motive. The US embargo in opposition to Cuba that started within the chilly conflict remains to be in impact, and tensions between the nations stay excessive.

However for these conversant in Cuba, its COVID vaccine growth ought to come as no shock – the nation has a lengthy historical past of producing its personal vaccines and medicines. Nor ought to or not it’s shocking that two of its COVID vaccines – Abdala and Soberana 02 – seem to have carried out very nicely in trials. Right here’s how they work.

Abdala is a protein subunit vaccine, which is a well-established design. The hepatitis B vaccine and Novavax COVID vaccine use this method. These vaccines work by delivering only a portion of the virus that they’re focused in opposition to – within the case of Abdala, bits of the coronavirus’s spike proteins, which cowl its exterior.

The proteins used within the vaccine aren’t taken from the coronavirus instantly. As a substitute, they’re grown in cells of a yeast (Pichia pastoris) which have been specifically engineered.

Cuban scientists working on vaccine development
Cuba has lengthy punched above its weight relating to healthcare and biotechnology.
Ernesto Mastrascusa/EPA-EFE

On their very own, the parts of spike protein are innocent. However when the immune system encounters them, it nonetheless trains itself to recognise and destroy them. If the complete coronavirus is then encountered sooner or later, the physique will assault these outer elements of the virus and shortly destroy it. Abdala is given in three doses.

The opposite Cuban COVID vaccine, Soberana 02, makes use of a “conjugate” design, alongside the strains of meningitis or typhoid vaccines. It comprises a distinct a part of the spike protein to Abdala and generates an immune response by attaching (conjugating) this to a innocent extract from the tetanus toxin. When the physique encounters these linked collectively, it launches a stronger immune response than it might to both alone.

Soberana 02 is produced in hamster ovary cells, a course of that may be sluggish, and this will prohibit large-scale manufacturing.

Initially, it was given as two doses, however researchers later recognized {that a} third dose could be helpful. This booster dose comprises simply the spike protein elements, with out the tetanus toxin, and is called “Soberana Plus”.

How efficient are they?

Each vaccines have been permitted by the Cuban regulator, although they began being rolled out in Might – earlier than authorisation had been granted – in response to an increase in instances. There have been considerations a couple of lack of understanding on their security and efficacy.


Hear: Cuba’s race to make its personal coronavirus vaccine – podcast


On November 1 2021, a preprint (analysis nonetheless awaiting overview) was lastly revealed of a Soberana part three trial that included 44,031 individuals. The outcomes recommend that two doses of Soberana 02 with a booster of Soberana Plus are collectively 92% protecting in opposition to symptomatic COVID. The preprint notes that in the course of the trial, the vaccine was most probably being examined in opposition to beta or delta – two variants of the coronavirus that different vaccines have discovered tougher to manage.

Earlier than this, a part 1 research of giving Soberana Plus to individuals who had already had COVID was revealed in September. This was testing the consequences of Soberana Plus as a booster to pure fairly than vaccine-induced immunity. It confirmed no questions of safety and stimulated a superb immune response when used on this method – although the research was small, involving simply 30 individuals.

For Abdala, the one part three trial information obtainable was issued by Cuban press releases in June and July 2021. The three-dose schedule can be reportedly 92% protecting in opposition to symptomatic COVID in addition to allegedly totally protecting in opposition to extreme illness and dying.

This generated enormous enthusiasm inside Cuba. Nonetheless, since then little additional data has been made publicly obtainable.

A man holding his son outside a paediatric hospital in Havana, Cuba
Cuba’s vaccine COVID protection is among the many greatest on the earth.
Yander Zamora/EPA-EFE

Round 90% of Cuba’s 11 million individuals have obtained a minimum of one dose of a COVID vaccine, with 82% thought-about totally vaccinated, and it seems Cuba is vaccinating kids as younger as two. Each Abdala and Soberana have been used, with round eight million individuals receiving three doses of Abdala.

Following a massive spike in instances in August 2021 – when the nation’s vaccine protection was nonetheless comparatively low – new infections in Cuba have since declined enormously and stay low. With out correct research, it’s tough to gauge how a lot of that is right down to the vaccines, however the virus’s suppression coinciding with the nation reaching excessive vaccine protection is a constructive signal.

Who may use a Cuban vaccine?

Given the tough relationship between Cuba and the US, the marketplace for Cuba’s vaccines will in all probability be its political allies. Vietnam and Venezuela are reported to have obtained Abdala doses, Nicaragua has given emergency authorisation to each vaccines, and doses have beforehand been despatched to Iran to be used in medical trials. Mexico and Argentina are additionally in utilizing these vaccines.

Cuba has submitted each to the World Well being Group (WHO) for approval, which might enhance the probability of them getting used overseas. If there are any plans to incorporate them within the Covax vaccine-sharing initiative, then WHO approval is a should.

In the meantime, we’re nonetheless ready to see what affect omicron may have. As long as there’s unequal entry to vaccines, the pandemic will proceed – and so too the danger of latest variants arising.

Given most richer nations aren’t within the queue for Abdala or Soberana 02, it’s solely attainable that in future, elements of South America, Asia and Africa – the place vaccine protection is notably low – might even see Cuban vaccines in lots of arms.

Supply: theconversation.com

The Conversation

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