Moderna COVID-19 vaccine successful against emerging variants, study shows

Moderna has announced results from in vitro neutralisation studies of sera from individuals vaccinated with the company’s COVID-19 vaccine showing activity against emerging strains of SARS-CoV-2.

According to the company, vaccination with the Moderna COVID-19 vaccine (mRNA-1273) produced neutralising titers against all key emerging variants tested, including B.1.1.7 and B.1.351, first identified in the UK and South Africa, respectively.

The study showed no significant impact on neutralising titers against the B.1.1.7 variant relative to prior variants. A six-fold reduction in neutralising titers was observed with the B.1.351 variant relative to prior variants. Despite this reduction, neutralising titer levels with B.1.351 remain above levels that are expected to be protective.

Therefore the two-dose regimen of mRNA-1273 at the 100µg dose is expected to be protective against all emerging strains detected to date. Moderna says it will test an additional booster dose of mRNA-1273 to study the ability to further increase neutralising titers against emerging strains beyond the existing primary vaccination series. The company is also advancing an emerging variant booster candidate (mRNA-1273.351) against the B.1.351 variant first identified in South Africa. mRNA-1273.351 is being advanced into pre-clinical studies and a Phase I study in the US to evaluate the immunological benefit of boosting with strain-specific Spike (S) proteins.

“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.”

The data has been submitted as a pre-print to bioRxiv and will be submitted for peer-reviewed publication.