Why we shouldn't halt the vaccine rollout Share Whoa! Before confidence in Australia’s vaccination program is completely shaken by calls to pause the rollout of the Astra Zeneca/Oxford vaccine, some issues need to be considered. Although the government has pushed back, data cited by the Australian and New Zealand Society for Immunology, which made the call, is correct. However, it is also preliminary and could change. A nurse delivers a second Pfizer-BioNTech COVID-19 vaccine jab to a health worker at a hospital in Michigan. AP So far, the Oxford vaccine is 62 per cent effective compared with about 95 per cent for the new technology RNA vaccines developed by Pfizer/BioNTech and Moderna.