CAJICA, Colombia – Previous research to develop vaccines for dengue and Zika virus could become the cornerstone for a vaccine against COVID-19, which the Autonomous University of Mexico (UNAM) is working on.

“We already have the manufacturing train for these viral particles at the lab, the whole purification train and we already have them well-characterized,” Laura Palomares, head of the research team at UNAM, told BioWorld.

“Sometimes, at the academy, we forget that producing a vaccine goes beyond having a candidate inoculated in an animal and see if it produces antibodies. To take a vaccine to market, you’ve got a much longer and complex road, and we’ve got the advantage of already having developed the Zika and dengue vaccines and taken them into the market,” she explained.

Palomares and her teams´ experience with the Zika and dengue vaccines, as well as the role they played in the development of the H1N1 vaccine in 2009, are the baseline for the Mexican team to work on the vaccine against the novel virus.

“The vaccines that made it to clinical trials so quickly, like the one of the DNA messengers or the one of the adenovirus in the U.K., are vaccines done like this, mounted on pre-existent platforms, where you only need to change the gene. In this case you would change the gene from the protein S of the coronavirus,” she explained.

The team’s goal is to block the receptor binding domain (RBD) from the S protein of SARS-CoV-2.

Palomares’ team is working with a protein of a virus that is different from COVID-19 and has self-assembly capabilities to form icosahedra as small as 20 nanometers, which are grated with epitopes that emulate or are part of the Zika and dengue viruses.

The team at UNAM is not working with the actual COVID-19 virus to develop its vaccine because it does not need to, at least not in the preclinical stage.

“What we did was to align the known sequences, including those from other coronaviruses, and identifying regions that we know don't vary too much. Also, we identified the regions the we know are the junctions for AC2, or other regions that we think are interesting, too,” said Palomares.

Palomares aims to start trials with mice and see if their immune systems recognize the engineered proteins as SARS-CoV-2 and trigger the creation of antibodies against them.

Despite logistical issues in Mexico due to lockdowns that are in place, Palomares expects to start working with mice in the next week or so. “We are really close [to start the animal models]. Basically, what is stopping us is that it is not easy to work nowadays. We need the bioterium to be [open], we need the mice to be crossed, [and] previous approval of ethics committees,” she said.

The second stage of development would be done with hamsters. “A second phase would need a level 3 safety bioterium. You vaccinate the hamsters, and then you expose them to the virus.

“I don't want to be too optimistic,” she said. “All this is done under a go-no go design, and we do loops, if we fail, to go back and try again,” she explained.

Made in Mexico

The team at UNAM has set the whole path for the development of the vaccine up until the point when it makes it to patients. While that stage could ultimately be hard to reach, it could help meet the second goal of the project: to prepare the lab to be one step ahead when the next pandemic hits.

“Obviously, our goal is to have a vaccine against SARS-CoV-2, but beyond that, our goal is to establish a platform in Mexico that allows us to respond much faster in the next pandemic,” said Palomares. “That is why others made it so fast to clinical trials, because they had [all the processes] in advance.”

UNAM signed a strategic partnership with Laboratorios Liomont, of Mexico City, which opened a plant late last year. The partnership would allow the company to manufacture up to 240,000 doses of biologic products per year. The company offered its installed capacity and capabilities to manufacture the products for the trial of the vaccine. It has partnered with UNAM for the development of biotech products.

At the moment, the only made-in-Mexico vaccines are for hepatitis B, produced by Probiomed SA de C.V., of Mexico City, using active pharmaceutical ingredients (APIs) made by Sanofi SA.

State-owned vaccine maker Birmex (Laboratorios Biológicos y Reactivos de México), of Mexico City, stopped manufacturing vaccines some time ago. Its last product was a polio vaccine.

Across all of Latin American, there are just two teams working on a vaccine against COVID-19.

Besides Unam, the Autonomous University of Querétaro (UAQ) is working on a vaccine that also targets protein S.

Both universities are applying for grants from the federal government of Mexico through the National Council of Science and Technology (Conacyt), which will fund with up to MXN$5 million (US$209,000) to kickstart projects.

The team at UNAM aims to raise $1.5 million from the public and private sectors to take its product into clinical trials.

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