CORBEVAX COVID-19 Vaccine: A Major Breakthrough for Low-Income Nations

A new COVID-19 vaccine has been added to the global toolkit, offering protection at a significantly lower cost per dose.

Two years since the COVID-19 pandemic began, the global toll exceeds 314 million cases and 5.5 million deaths. Around 60 percent of the global population has received at least one dose of a COVID-19 vaccine. However, a stark and concerning disparity in vaccine access persists worldwide. As a virologist closely monitoring this crisis, I argue that this inequity in vaccine distribution should be a pressing concern for all.

One key lesson from the pandemic is that viruses know no borders. Despite this, roughly 72 percent of vaccine doses have been administered in high- and upper-middle-income nations, with just 1 percent reaching low-income countries. While wealthier nations are rolling out booster and even fourth doses, many around the world still lack access to their first and second shots.

However, a promising new vaccine named CORBEVAX offers hope for bridging this vaccination divide.

How Does the CORBEVAX Vaccine Work?

All COVID-19 vaccines train the immune system to recognize the virus and prepare defenses. The CORBEVAX vaccine, a protein subunit vaccine, introduces a harmless fragment of the coronavirus spike protein to prime the immune system for potential future infections.

Unlike the three U.S.-approved vaccines—Pfizer and Moderna's mRNA vaccines and Johnson & Johnson's viral vector vaccine, which instruct the body to produce the spike protein—CORBEVAX delivers the spike protein directly. Similar to other mRNA vaccines, CORBEVAX also requires two doses.

How Was CORBEVAX Developed?

The development of CORBEVAX was led by Drs. Maria Elena Bottazzi and Peter Hotez, co-directors of the Texas Children's Hospital Center for Vaccine Development at Baylor College of Medicine.

In response to the 2003 SARS outbreak, the team engineered a comparable vaccine by integrating genetic material from a segment of the SARS virus spike protein into yeast, enabling mass production of the protein. After extracting the spike protein and combining it with an adjuvant to enhance immune activation, the vaccine was prepared for deployment.

The initial SARS epidemic was brief, leaving Bottazzi and Hotez's vaccine largely unused—until the emergence of SARS-CoV-2, the virus responsible for COVID-19, in 2019. They revisited their earlier work, modifying the spike protein to align with SARS-CoV-2, resulting in the creation of the CORBEVAX vaccine.

Extensive clinical trials in the U.S. demonstrated the vaccine's safety, tolerability, and over 90 percent efficacy in preventing symptomatic infections. With emergency use authorization granted in India, other developing nations are anticipated to adopt it soon.

Surprisingly, the Baylor team struggled to garner interest or secure funding in the U.S. for their vaccine. Despite their vaccine design being more advanced due to their experience with the 2003 SARS and 2012 MERS outbreaks, newer technologies like mRNA vaccines took precedence.

A Vaccine Built for the World

Protein subunit vaccines offer a significant advantage over mRNA vaccines, as they can be manufactured using established recombinant DNA technology, which is cost-effective and scalable. This technology, similar to the one used for the Novavax COVID-19 vaccine—available in 170 countries—and the recombinant hepatitis B vaccine, has been in use for decades.

The scalability of this vaccine is enhanced by the availability of suitable manufacturing facilities. Additionally, CORBEVAX's ability to be stored in a standard refrigerator makes global distribution feasible. In contrast, producing mRNA vaccines is costlier and more complex, requiring advanced technology, skilled labor, and often ultralow temperature storage.

A key distinction of the CORBEVAX vaccine is its focus on global accessibility. Designed to be affordable, easy to produce, and transportable, it utilizes a proven and safe method. The researchers prioritized public health over intellectual property or profit, and the $7 million development cost was funded by philanthropists.

Currently, CORBEVAX is licensed without patents to Biological E. Limited (BioE), India's leading vaccine manufacturer, which aims to produce over 100 million doses monthly starting February 2022. This patent-free model allows other low- and middle-income nations to locally manufacture and distribute this affordable, stable, and scalable vaccine.

As a result, CORBEVAX stands out as one of the most cost-effective vaccines available today. Its efficacy against the omicron variant is still being studied. Nonetheless, the CORBEVAX initiative serves as a blueprint for tackling vaccine inequity, essential for global immunization efforts against COVID-19 and future diseases.

The Necessity of Vaccine Equity

Numerous factors contribute to global vaccine inequity. For instance, affluent nations pre-purchase vaccines, reducing availability. Although developing countries possess vaccine production capabilities, many in Africa, Asia, and Latin America still struggle to afford bulk orders.

The Indian government has secured 300 million doses of CORBEVAX, with BioE aiming to manufacture over 1 billion doses for developing nations. In comparison, the U.S. and G-7 countries have committed to donating more than 1.3 billion COVID vaccine doses, but only 591 million have been delivered. If BioE achieves its target of 1.3 billion doses, CORBEVAX will outpace the donations from the wealthiest nations in reaching people.

The rapid global spread of the omicron variant highlights how new variants thrive in unvaccinated populations and will continue to arise as long as vaccination rates remain low worldwide. Relying solely on boosters is unlikely to end the pandemic. Instead, vaccines like CORBEVAX, designed for global accessibility, are crucial for widespread immunization and pandemic control.

Maureen Ferran is an associate professor of biology at the Rochester Institute of Technology. She receives funding from The National Institutes of Health.

This article is republished from The Conversation under a Creative Commons license. You can find the original article here.