Moderna vaccine booster jab shows strong promise against ‘SA variant’

A multivalent Covid-19 jab developed by US vaccine manufacturer Moderna has shown promising results against the so-called “SA variant” of the coronavirus, the company said on Tuesday.

The vaccine, which combines Moderna’s original Covid-19 vaccine with a new booster vaccine designed to work against new variants of the virus, increased neutralising antibody titres in mice against the new variants.

Titres are blood tests that determine the levels of antibodies present in blood samples.

Moderna said on Tuesday that a six-month follow-up of its original study showed its vaccine offered strong protection against illness six months after people received their second shot, and claimed efficacy of more than 90% against all cases of Covid-19.

“A boost at six months with mRNA-1273.351 closed the neutralising titre gap for the variants of concern,” the company said.

While some 11 Covid-19 vaccines are in use globally, there are widespread fears that many will offer greatly reduced protection against new variants of the virus discovered in SA, Brazil and the UK.

In February, Moderna announced it had completed manufacturing of clinical trial material for its variant-specific vaccine candidate against the B.1.351 variant first identified in SA in November last year.

The experimental doses had been shipped to the US National Institutes of Health (NIH) for a phase one clinic trial, the company said.

The multivalent vaccine offered the highest level of protection, the report said.

US-based Moderna focuses on using messenger ribonucleuc acid (mRNA), a vital part of the human body’s genetic code, to help fight disease.

mRNA are sets of “instructions” through which cells manufacture proteins and distribute them around the body.

Moderna was due to brief investors on Wednesday on the progress of its global vaccine rollout. The company had supplied 132 million vaccine doses globally as of April 12, it said.

Around 67 million doses of its vaccine had been administered in the US by the end of March

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