The majority of individuals vaccinated with the Moderna COVID-19 vaccine maintained both binding and functional antibodies against SARS-CoV-2 variants for six months after the second dose, according to new data published in Science.

This study used a variety of assays and showed that after two doses of the Moderna COVID-19 vaccine, binding and neutralizing antibodies were generated against ancestral strain of the virus and against the variants of concern, Alpha, Beta, Gamma, Delta, Epsilon and Iota. While some waning in antibody levels was observed over time, the majority of participants had detectable neutralizing antibody titers at six months after the completion of the primary series.

A trend towards lower antibody levels against SARS-CoV-2 spike variants was observed in the oldest individuals at Day 209 (through six months). Differences were small, however, and there was overlap between age groups. Importantly, many individuals in the oldest group retained neutralizing activity against the variants six months after the second vaccine dose.

These data complement other recent observations based on real world evidence demonstrating robust longevity of clinical efficacy of the Moderna COVID-19 vaccine1, effectiveness in the face of rising levels of the Delta variant of concern2 and in those harder to treat populations such as those people in long term care facilities3, or those patients living with cancer4.

“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. Along with our partners, we are committed to generating data on the Moderna COVID-19 vaccine and sharing this as available,” said Stéphane Bancel, Chief Executive Officer of Moderna. “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.”

References provided by Moderna Inc.

1 https://www.medrxiv.org/content/10.1101/2021.08.06.21261707v1
2 https://www.medrxiv.org/content/10.1101/2021.08.11.21261885v1
3 https://www.medrxiv.org/content/10.1101/2021.08.06.21261721v1
4 https://www.nature.com/articles/s41375-021-01354-7