JessieJay said " "
It's not that it was ineffective, there just wasn't data as it wasn't initially tested on that age group. They have since done additional testing and now there's data.
"In a statement, AstraZeneca said its COVID-19 vaccine had a 79 per cent efficacy rate at preventing symptomatic COVID-19 and was 100 per cent effective in stopping severe disease and hospitalization." Investigators said the vaccine was effective across adults of all ages, including older people — which previous studies in other countries had failed to establish.
"These findings reconfirm previous results observed," said Ann Falsey of the University of Rochester School of Medicine, who helped lead the trial. "It's exciting to see similar efficacy results in people over 65 for the first time."
https://www.cbc.ca/news/world/astrazeneca-oxford-trial-efficacy-1.5958717
"In a reversal of its own guidance issued earlier this month, Canada’s National Advisory Committee on Immunization (NACI) is now recommending that AstraZeneca’s COVID-19 vaccine be used on people aged 65 or older.
The committee now says “real-world evidence” has demonstrated that the vaccine is safe and effective in older adults, particularly against severe illness from COVID-19 and hospitalization.
Still, if there is a choice, NACI says mRNA vaccines — like Pfizer’s and Moderna’s — should be prioritized for use on seniors, but that it no longer recommends against using AstraZeneca for anyone over the age of 65."
https://globalnews.ca/news/7698838/astrazeneca-naci-guidelines-seniors/
The best vaccine is the first one offered to you. All are 100% or near 100% effective at preventing severe illness and death.