Moderna has reported that its Covid-19 messenger ribonucleic acid (mRNA) vaccine provided durable efficacy in producing neutralising antibodies against SARS-CoV-2 variants of concern in a study.
Authorised for emergency use in more than 50 countries, the vaccine encodes for a prefusion stabilised form of the Spike (S) protein.
The latest study utilised various assays and found that two doses of the vaccine generated binding and neutralising antibodies against ancestral strain, as well as variants of concern, including Alpha, Beta, Gamma, Delta, Epsilon and Iota.
Furthermore, most of the inoculated subjects maintained the binding and functional antibodies against the variants for six months following the second dose.
Moderna noted that antibody levels waned to some extent over time but most of the study subjects were observed to have detectable levels of neutralising antibody titers at six months.
At day 209 through six months, a trend towards reduced antibody levels against spike variants was noted in the oldest participants.
An overlap between age groups was reported even though the differences were minimal.
In addition, several people in the oldest group maintained neutralising activity against the variants six months from the second dose of the vaccine, the company added.
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 results complement previous real-world data showing strong durability of clinical efficacy of the vaccine, its efficacy against Delta variant and in hard-to-treat people.
In May this year, Moderna reported that the Phase II/III TeenCOVE study of its Covid-19 vaccine met the primary immunogenicity goal in adolescents, with immune responses similar to those seen in adults.