Moderna two-strain booster vaccine
August 16, 2022 - Moderna’s bivalent coronavirus vaccine contains two components which attack both the original strain of the virus and the Omicron variant with antibodies and immune response cells.
Britain has become the first country to green light U.S. drug company Moderna’s variant-adapted vaccine for the country’s booster campaign starting September.
The Medicines and Healthcare products Regulatory Authority based its decision on clinical trial data that showed the booster triggered “a strong immune response” against the BA.1 Omicron variant and the original virus.
In June, Boston-based Moderna reported that trial data showed that when given as a fourth dose, the two-strain vaccine raised virus-neutralising antibodies by eight-fold against Omicron.
The pioneering messenger RNA booster shot contains mRNA-1273 -- the original Spikevax -- and a vaccine candidate which targets the Omicron variant of concern.
The vaccine cocktail works by preparing the body to defend itself against both coronavirus strains. The mRNA molecule has instructions for making the spike proteins of both variants, and spike proteins on the coronavirus surface allow it to enter human cells.
When vaccinated with the bivalent shot, some of a person’s cells will read the mRNA instructions and temporarily produce the spike proteins of both variants. The person’s immune system will then recognise these proteins as foreign, produce antibodies, and activate T cells (white blood cells) to attack them. The proteins and mRNA disappear from the body in a matter of days.
“We are thrilled to share the preliminary data analysis on mRNA-1273.214, which is the second demonstration of the superiority of our bivalent booster platform against variants of concern,” said Stéphane Bancel Chief Executive Officer of Moderna.