Moderna Applies Two-Pronged Strategy to Fight against Coronavirus Variants 

On January 25th, Moderna reported that its COVID-19 vaccine could combat the coronavirus variants that emerged in the UK, however, it is less effective against the one found in South Africa. As a result, Moderna will study booster doses of its vaccine (mRNA-1273) along with an additional vaccine (mRNA-1273.351), which is tailored to fight the new strains.

After new variants emerged in the UK and South Africa, a state of panic ensued amongst scientists who had been working on a COVID-19 vaccine for almost a year. They doubted whether their vaccines would be able to protect against these new strains, which have high transmission rates and a higher viral burden after infection.

Last week, Pfizer reported that its vaccine holds up against the UK variant, but it did not report any data against the South African variant. Moderna, however, made sure to include the South African variant in its study that is more efficient at dodging killer antibodies in the bloodstream.

The Study

Moderna derived the efficacy data by examining blood samples from eight people who had received two doses of the vaccines and two monkeys that have been immunized. In the study, Moderna showed that at the current dosage levels, its COVID-19 vaccine generated a similar response (neutralizing antibodies) against the UK variant when compared to prior variants.

However, a six-fold reduction in the response was observed against the South African variant. Despite this, the company says that the levels of neutralizing antibodies remained above the levels that are “expected to be protective.”

Nevertheless, the company is concerned that “the lower titers may suggest a potential risk of the earlier waning of immunity to the new B.1.351 (South African) strain.” And, therefore, out of an abundance of caution, it will launch at least two clinical efforts that would boost immunity to emerging coronavirus variants.

Moderna’s Two-pronged Approach

Moderna is planning to test two strategies to fend mutant strains. The first step is to use the additional booster dose of the original vaccine to ramp up defenses against the strains. If this strategy works, the public would have to take three shots of the vaccine against two that were recommended for the original strain. The second strategy is to develop a new vaccine candidate using the strain-specific spike protein and test its efficacy in the phase 1 study in the US.

“As we seek to defeat the COVID-19 virus, which has created a worldwide pandemic, we believe it is imperative to be proactive as the virus evolves. We are encouraged by these new data, which reinforce our confidence that the Moderna COVID-19 Vaccine should be protective against these newly detected variants,” said Stéphane Bancel, Chief Executive Officer of Moderna.

“Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers against this and potentially future variants.”

How Problematic are the Variants?

Paul Offit, MD, director of the Vaccine education center at Children’s Hospital of Philadelphia, told CNBC “This is not a problem yet. Prepare for it. Sequence these viruses. Get ready just in case a variant emerges, which is resistant.”

As of Friday, 195 patients have been infected with the UK variant of the coronavirus in the US. No cases from the South African variant have been confirmed in the country yet, and the ban on air travel from South Africa has been installed to keep the variant from coming into the country.

However, Dr. Fauci is worried that if the spread of the virus is not controlled quickly, it will keep on mutating. Dr. Fauci said, “We need to get as many people vaccinated with the current vaccine that we have as we possibly can and prepare for the potential eventuality that we might have to update this vaccine sometime in the future.”

Related Article: COVID-19: Another Study Suggests Pfizer/BioNTech Vaccine is Capable of Neutralizing UK Variant

References

1. https://investors.modernatx.com/news-releases/news-release-details/moderna-covid-19-vaccine-retains-neutralizing-activity-against
2. https://www.cnbc.com/2021/01/25/covid-vaccine-moderna-working-on-covid-booster-shots-for-south-african-strain.html

Author

Ruchi Jhonsa