WASHINGTON, United States (AFP) — US biotech firm Moderna said Wednesday that doses of its new COVID-19 vaccine candidate aimed at the South African coronavirus variant had been shipped to the US National Institutes of Health for testing.

“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 CEO Stephane Bancel.

The South African variant is considered among the more dangerous of current mutations because it evades some of the blocking action of antibodies that target the older coronavirus strain.

That means people who were infected with the classic strain are more susceptible to reinfection, and research has also shown the variant has partly reduced the protection of the current generation of vaccines.

While initial testing has shown that Moderna’s original vaccine — called mRNA-1273 — remains effective against emerging variants, the company said it was pursuing the development of a variant-specific vaccine as part of a number of strategies being considered.

Either a South Africa variant-specific candidate, called mRNA-1273.351, could be used as a booster, or the company might use a booster that combines the classic vaccine with the variant-specific mRNA-1273.351 to create a new product.

Another idea is that people could receive a third dose of the classic vaccine to raise their overall immunity.

Moderna is also looking at the possibility of using the South Africa variant-specific mRNA-1273.351 or the combination shot as the primary dose.

The US Food and Drug Administration announced Monday that drug makers developing variant-specific vaccines wouldn’t need to go through the same lengthy authorisation process they had to for their original shots.

Moderna also announced it was raising its global manufacturing capacity and would be able to produce up to 1.4 billion doses of its vaccine in 2022 if needed.

Additionally, it said it was increasing its plan for 2021 manufacturing from 600 million doses to 700 million doses globally. Moderna has so far shipped 60 million doses, 55 million within the US.