Results from a phase 1 study of Moderna’s COVID-19 vaccine candidate have shown promise in older adults, with the vaccine generating a strong immune response in this population.
The results from the study supported by the US National Institutes of Allergy and Infectious Diseases (NIAID) were published in the New England Journal of Medicine yesterday.
The new data builds and expands on the initial results released n August detailing the efficacy of Moderna’s mRNA-1273 vaccine in 20 adults between the ages 56-71 and older.
The updated results come from an expansion of the trial which included a larger proportion of older adults, comprising 20 adults aged 56-70 years old and 20 adults aged 71 years and older.
Ten volunteers in each age group received a lower dose of the vaccine – 25 µg – and the other ten received a higher dose of 100 µg. Participants then received a second dose of the same vaccine at the same dosage a month later.
The researchers found that the mRNA-1273 vaccine was well-tolerated in this older age group, with participants exhibiting a good immune response following administration of two doses of the vaccine.
Notably, the blood of participants vaccinated with Moderna’s vaccine contained robust binding and neutralising antibodies against the SARS-CoV-2 virus, which causes COVID-19. The presence of neutralising antibodies is an important early indicator of efficacy at this stage of clinical testing.
More importantly, the levels observed in older participants was comparable to younger volunteers – experts have raised concerns that a potential vaccine against COVID-19 may not be as effective in this population, as the elderly are likely to have a weaker immune system compared to younger people.
However, Moderna has quelled some of these fears with the expanded trial results, especially given that the vaccine was deemed safe to use, with only some older volunteers experiencing transient adverse events including fever and fatigue after vaccination.
“Given the increased morbidity and mortality of COVID-19 in older and elderly adults, this data gives us optimism in demonstrating mRNA-1273’s protection in this population, which is being evaluated in the phase 3 COVE study,” said Tal Zaks, chief medical officer of Moderna.
Following the positive results, the study will continue to follow the older participants for approximately a year to monitor the long-term effects of the vaccine. The data also supports further testing of the investigational vaccine candidate in older adults in an ongoing phase 3 trial.