Interim Results Show Strong Immune Responses and Better Tolerability in Older Adults for AZD1222

Published on: 

Interim results of AZD1222 trial have demonstrated lower reactogenicity in older adults, and strong immune responses across all adult age groups.

Interim results from the Phase II/III trial of the AstraZeneca Oxford coronavirus vaccine, AZD1222, have demonstrated lower local and systemic reactions in older adults compared with younger adults, and strong immune responses across all adult age groups.

The results, which have been published in a study in The Lancet and were announced in a Nov. 19, 2020 press release, confirm that the frequency of reactions to the injection of the AZD1222 vaccine reduced with increasing age of the patient. Reactions to the treatment included temporary injection site pain and tenderness, fatigue, headache, feverishness, and myalgia.

Immune responses were robust across all age groups, with detection of a response being seen in 100% of participants by day 28, irrespective of age of vaccine dosage. Additionally, the immune response was boosted with a second dose of the vaccine. Furthermore, neutralizing activity was seen in all participants by day 14 after they had received the second dose of the vaccine and T-cell responses were induced, peaking at day 14, after the first dose of the vaccine was administered.


“It is essential that a COVID-19 vaccine can be effective across a broad age range, particularly in older individuals where they are disproportionately at risk of severe COVID-19 disease,” said Mene Pangalos, executive vice-president, BioPharmaceuticals R&D, in the press release. “The Phase II interim data for AZD1222 suggests older individuals have lower reactogenicity whilst still maintaining a robust immune response.”

Source: AstraZeneca