Thread by @SkyScottBeasley

💉 NEW: One dose of AstraZeneca/Oxford vaccine offers 76% protection after day 22 post vaccination - and offers sustained protection through a 3 month period until second dose

New analysis by Oxford University

▶️ vaccine shows sustained protection of 76% during the 3-month interval until the second dose

▶️ analyses shows single standard dose efficacy from day 22 to day 90 post vaccination of 76% with protection not falling in this three-month period

▶️ After the second dose vaccine efficacy from two standard doses is 82.4% with the 3-month interval being used in the UK

▶️ 82.4% effective, with a 95% confidence interval of 62.7% - 91.7% at 12+ weeks

Oxford says this supports the extended time period between doses- AZ have always said longer was more effective:

Oxford: “Data supports the 4-12 week prime-boost dosing interval recommended by many global regulators”

🦠 Crucially, Oxford says the vaccine DOES stop transmission:

Oxford: “Analyses of PCR positive swabs in UK population suggests vaccine may have substantial effect on transmission of the virus with 67% reduction in positive swabs among those vaccinated”

Prof Andrew Pollard, Chief Investigator of Oxford Vaccine Trial, co-author of the paper: “These new data provide an important verification of the interim data that was used by more than 25 regulators including the MHRA and EMA to grant the vaccine emergency use authorisation”

“It also supports the policy recommendation made by the Joint Committee on Vaccination & Immunisation for a 12-week prime-boost interval, as they look for the optimal approach to roll out, & reassures us that people are protected from 22 days after a single dose of the vaccine”

Crucially-as AZ & scientists have repeatedly said-extending interval INCREASES efficacy

Oxford: “the effect of dosing interval on efficacy is pronounced, with vaccine efficacy rising from 54.9% with an interval of less than six weeks to 82.4% when spaced 12 or more weeks apart”

📔 This research is published by researchers at the University of Oxford in Preprints with The Lancet

You can find it here
papers.ssrn.com/sol3/papers.cf…

Increased efficacy with longer interval is not unusual-that’s usual with many vaccines

Remember the AZ vaccine uses old fashioned technology- so they were always confident it would work this way

The mRNA vaccines (eg Pfizer) are new so we don’t have years of data/experience

To be very clear: this analysis makes no mention or claims about new geographic variants

The data is from phase 3 trials in the UK, South Africa and Brazil up to early December. As above - there is no information on different levels of efficacy against new geographical variants

🏥 A crucial point- what do we REALLY need to stop? Hospitalisations and deaths.

Like the other vaccines-this vaccine is extraordinarily effective at stopping very serious disease

There were NO hospitalisations in the vaccinated group in the trials - but 15 in the placebo group

Key finding: “ChAdOx1 nCoV-19 programmes aimed at vaccinating a large proportion of population with single dose, with second dose given after 3 months is an effective strategy for reducing disease, & may be optimal for rollout of a pandemic vaccine when supplies are limited”