Interim results from the ongoing Phase II/III COV002 trial of AZD1222 in the UK, led by the University of Oxford, demonstrated lower local and systemic reactions in older adults (≥56-69 years and ≥70 years) than younger adults (≥18-55 years) and generated similar robust immune responses against the SARS-CoV-2 virus across all adult age groups.

“Generated similar robust immune responses against the SARS-CoV-2 virus across all adult age groups.”

COV002 is a blinded, multi-centre, randomized, controlled Phase II/III trial in 12,390 participants in the UK. In the Phase II trial, participants aged 18 years or over are randomized to receive either one or two standard or low doses, given one month apart of AZD1222, or the MenACWY comparator vaccine, by intramuscular injection.

Results published in the Lancet

The results published in The Lancet confirm that transient, predominantly mild, local and systemic reactions were common in the AZD1222 group and were comparable to interim data previously reported with the vaccine from the Phase I/II trial and other adenoviral vector vaccines. They included temporary injection site pain and tenderness and fatigue, headache, feverishness and myalgia. Fewer reactions were experienced after a second dose of AZD1222 and with the lower dose. The frequency of reactions were also reduced with increasing age.

Antibody responses to the SARS-CoV-2 virus spike protein were detected by day 28 in 100% participants, regardless of age or vaccine dosage and continued to rise after a second dose of AZD1222. Neutralising activity was seen in 100% participants by day 14 after receiving a second standard dose, regardless of age. T-cell responses were induced, peaking by day 14 after the first dose and were maintained two months after injection, regardless of age and dosage.

“The Phase II interim data for AZD1222 suggests older individuals have lower reactogenicity whilst still maintaining a robust immune response.”

“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. The Phase II interim data for AZD1222 suggests older individuals have lower reactogenicity whilst still maintaining a robust immune response,” says Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca.

Clinical trials of AZD1222 are ongoing globally across UK, US, Brazil, South Africa, Japan, Russia and Kenya recruiting up to 60,000 participants across a broad age range and diverse racial, ethnic and geographic groups. Initial late-stage trial results are expected before the end of the year depending on the infection rate within the trial communities.

Photo of Mene Pangalos: AstraZeneca