Thread by @DrEricDing

💡EFFECTIVE—Single-dose Oxford–AstraZeneca #COVID19 vaccine followed by a 12-week booster. Vaccine efficacy was significantly higher at 81·3% after two standard doses given at an interval of >=12 weeks, versus 55·1% when doses <6 weeks apart. Good news! 🧵
thelancet.com/journals/lance…

2) “findings were supported by immunogenicity studies done in participants who were younger than 55 years, showing anti-SARS-CoV-2 spike IgG antibody responses more than two-fold higher in those who had a dose interval of >=12 weeks than in those who had an interval of <6 weeks”

3) “Notably, efficacy against any nucleic acid amplification test-positive cases, including symptomatic and asymptomatic or unknown cases, was 63·9% (46·0 to 75·9) after a single standard dose, suggesting the possibility of reducing viral transmission.”

4) “A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce...”

5) ...”while also improving protection after receiving a second dose.”

thelancet.com/journals/lance…

6) Plotting anti-SARS-CoV-2 spike IgG against vaccine efficacy for each dose interval showed evidence of a potential relationship between binding antibody and vaccine protection, as well as between neutralisation antibody and vaccine efficacy (figure 4).

7) New data from Israel also shows promise for just a single initial shot - and for asymptomatic as well!

https://twitter.com/DrEricDing/status/1362589110951702531