While vaccine inequality between higher and lower-income nations continues to persist, a team of scientists in Texas has developed what they hope to be “the world’s COVID vaccine,” a low-cost and not-for-profit shot designed to help middle- to low-income countries fight against the COVID-19 pandemic.
Known as Corbevax, this vaccine was developed by Texas Children's Hospital and Baylor College of Medicine in Houston. In the last week of 2021, the vaccine received emergency approval by the government of India and the Ministry of Health and Family Welfare has already pre-ordered 300 million doses, meaning it’s all set to start rolling out.
“This announcement is an important first step in vaccinating the world and halting the pandemic. Our vaccine technology offers a path to address an unfolding humanitarian crisis, namely the vulnerability the low- and middle-income countries face against the delta variant,” Dr Peter Hotez, Professor and Dean of the National School of Tropical Medicine at Baylor and Co-Director of the Texas Children’s Hospital Center for Vaccine Development, said in a statement.
“Widespread and global vaccination with our… vaccine would also forestall the emergence of new variants. We have previously missed that opportunity for the alpha and delta variant. Now is our chance to prevent a new global wave from what might follow,” added Hotez.
This “second generation” vaccine is a recombinant protein subunit vaccine. It works by containing a version of the receptor-binding domain of the SARS‑CoV‑2 spike protein, a key part of a virus that allows it to dock to body receptors to gain access to our cells. When this harmless protein is introduced to the body, the immune system learns to recognize it promptly and produces antibodies to fight it, preparing it for a potential future infection. The protein is produced by the microbial fermentation of yeast in a way that’s relatively easy to scale up at a low cost.
While this type of vaccine has been successfully used for around four decades, notably the Hepatitis B vaccination, it’s a first for COVID shots. To further boost access to the vaccine, the development team has also handed over its production to India-based Biological E. Limited (BioE) with a "no-strings" open license. They estimate they have the capacity to produce about 1.2 billion doses per year, priced at ₹250 (around $3) per dose, making it the most affordable of vaccines in the Indian market.
The technology behind Corbevax has been around for a substantial amount of time, meaning there’s a good understanding of how it works and its safety. However, the safety and efficacy of the novel vaccine have, of course, been proven by two Phase III clinical trials involving 3,000 people. According to Texas Children’s Hospital, the trials found that Corbevax was over 90 percent effective at preventing symptomatic infections of the original "Ancestral-Wuhan strain" and over 80 percent effective for the prevention of symptomatic Delta variant infections. None of the participants reported any serious adverse events either.
“Protein-based vaccines have been widely used to prevent many other diseases, have proven safety records, and use economies of scale to achieve low-cost scalability across the world,” added Dr Maria Elena Bottazzi, Professor and Associate Dean of the National School of Tropical Medicine at Baylor and Co-Director of the Texas Children’s Hospital Center for Vaccine Development.
With all of this in place, Corbevax must start its mammoth challenge to help ease the vaccine inequality and start boosting immunity to parts of the world that need it most.