Thread by @jburnmurdoch

SCOOP:

Public Health England has presented the first real-world data on vaccine efficacy against B.1.617.2, the variant first found in India.

Efficacy against symptomatic B.1.617.2 was 81% after two doses, much higher than many have feared.

Story: ft.com/content/a70d42…

I would ask people to read what follows carefully. Vaccine efficacy is a nuanced topic and the numbers here need to be interpreted in their proper context.

The data, which the FT has seen, suggest first dose offers around 35% less protection against symptomatic infection with B.1.617.2 compared to B.1.1.7, but after two doses the relative drop is only 7%.

The figures are based on pooled data from the Pfizer and AstraZeneca vaccines

Those relative reductions are FT calculations based on data showing that after one dose, protection against symptomatic infection with B.1.1.7 is 51%, falling to 33% for B.1.617.2.

And after two doses it's 87% for B.1.1.7 and 81% for B.1.617.2, a very high level of protection.

Those first dose figures of 51% and 33% may sound low, but need interpreting in their proper context:

First dose efficacy was previously estimated at between 55% and 70%, with a lot of this based on the 'pre-variant era', as it were assets.publishing.service.gov.uk/government/upl…

Relative to that, 51% for B.1.1.7 is a small dip (if any) and one we’ve been living with. The life-saving vaccine effect we’ve seen in the UK recently is based on that level.

33% for B.1.617.2 means a modest 35% relative reduction. Not tiny, not huge, and better than for B.1.351

After two doses, the range of protection we’ve been living with is 85-90%.

The new data showing 87% for B.1.1.7 implies ~zero drop-off.

81% for B.1.617.2 is a very small dip and the confidence intervals overlap with the 85-90% range, so it’s possible there is no drop-off at all

The data suggest less vaccine escape than with B.1.351, the variant first identified in South Africa. An earlier study from Qatar found a first dose offered only 17% protection against a confirmed case of B.1.351, rising to 75% after two doses nejm.org/doi/10.1056/NE…

No PHE data yet on protection against severe disease, but it will be higher.

Two doses will give very strong protection against hospitalisation with B.1.617.2, and a single dose may also offer high protection.

Chart below is from nature.com/articles/s4159… (red lines are mine)

Separate data presented by Public Health Scotland also point to strong protection against B.1.617.2 after two doses, with minimal reduction compared to B.1.1.7.

Strong efficacy after two doses is also supported by the latest figures from Bolton, which show case rates among the over-60s (78% have two doses) low and stable, despite a sharp acceleration among younger, less-vaccinated age groups.

The key take-aways:
• Yes, there are signs B.1.617.2 has some ability to evade protection against infection, but that evasion is on the small side
• Evasion against hospitalisation will be smaller still, if there is any at all
• Two doses offer extremely good protection

Here’s our story again: ft.com/content/a70d42…

Oh, and a nice little footnote:

After weeks of growing FOMO as dozens of friends and family got their vaccines, I’m now booked in for both doses 💉💉💪💪

It’s nice to have that personal win alongside this good news for the rest of us 😀

Very belated addendum: story was done with @AnnaSophieGross & @SarahNev, two extremely cool heads in a high-pressure situation, and fastidiously edited by @andrewparker67.

The best thing about working for the FT is the colleagues 🙌🙌🙌