Moderna has announced that in a new study its Covid-19 messenger ribonucleic acid (mRNA) vaccine showed durable efficacy in generating neutralising antibodies against SARS-CoV-2 variants of concern.
The vaccine, which encodes for a prefusion stabilised form of the Spike (S) protein, is authorised for emergency use in over 50 countries.
The study, which saw use of several assays, found that two doses of the vaccine produced binding and neutralising antibodies against ancestral strain of the virus besides variants of concern, including Beta, Gamma, Alpha, Delta, Epsilon and Iota.
After the second dose, most of the inoculated subjects were also found to have maintained the binding and functional antibodies against the variants of concern for six months.
The firm stated that although antibody levels waned to some extent over time, most of the participants were found to have detectable levels of neutralising antibody titers at six months.
It was found at day 209 (through six months) that there was a trend towards reduced antibody levels against SARS-CoV-2 spike variants in the oldest individuals.
An overlap between age groups was found; however, the differences were small.
Furthermore, many people in the oldest group retained neutralising activity against the SARS-CoV-2 variants six months after the second dose of Moderna’s Covid-19 mRNA vaccine.
Moderna CEO Stéphane Bancel said: “We are pleased with these new data showing that people vaccinated with two doses of the Moderna Covid-19 vaccine maintained antibodies through six months, including against variants of concern such as the Delta variant.
“These data support the durable efficacy of 93% seen with the Moderna Covid-19 vaccine through six months.
“We expect that these data and the growing body of real-world evidence will help inform health regulators’ approaches to how and when to administer additional boosting doses.”
The latest study results complement earlier real-world evidence that indicated strong longevity of the vaccine’s clinical efficacy, its effectiveness against Delta variant as well as in harder-to-treat populations.