Moderna has shipped doses of a variant-specific vaccine candidate against the COVID-19 variant first discovered in South Africa, otherwise known as B.1.351, to the US National Institutes of Health (NIH) for clinical study.

The company also said in a statement that it has completed manufacturing of clinical trial material for the new vaccine candidate, called mRNA-1273.351.

The shipped doses will be used for a Phase I clinical trial, to be led and funded by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID).

To address new and emerging strains of COVID-19, Moderna said in a statement that it is pursuing two strategies against variants.

The first strategy includes evaluating booster doses of its vaccine to increase neutralising immunity against variants of concern.

As part of this first strategy, Moderna plans to evaluate three approaches to boosting, including the mRNA-1273.351 variant-specific booster candidate based on the B.1.351 variant, a multivalent booster candidate which combines Moderna’s authorised vaccine – mRNA-1273 – with mRNA-1273.351 and a third dose of mRNA-1273 as a booster dose.

The second strategy will see Moderna evaluate the multivalent booster candidate – known as mRNA-1273.211 – and mRNA-1273.351 as a primary vaccination series for those who are seronegative.

The company will also evaluate the immunogenicity and safety in participants who have not received a COVID-19 vaccine and participants in clinical studies who have previously received mRNA-1273.

“We look forward to beginning the clinical study of our variant booster and are grateful for the NIH’s continued collaboration to combat this pandemic,” said Stéphane Bancel, chief executive officer of Moderna.

“As we seek to defeat COVID-19, we must be vigilant and proactive as new variants of SARS-CoV-2 emerge,” he added.