- A chart shows vaccine protection against Omicron after one, two, or three shots.
- Protection is high against severe disease, and is boosted by a third shot, per official UK stats.
- Protection against getting mildly ill is much lower, although a booster raises it.
A new chart hows how much protection is conferred by one, two, and three doses of vaccine against the Omicron coronavirus variant.
It was published on Friday by the UK’s Health Security Agency, drawing on data collected during the country’s Omicron surge in late December.
Protection against hospitalization waned over time after a second dose, but a booster shot increased it again, the figures showed.
The study was based on data collected between 27 November and 24 December 2021. It provides the first formal assessments of booster vaccine effectiveness against severe disease, Eric Topol the director of the Scripps Research Translational Institute, tweeted on Friday.
Here are the stats.
For hospitalization (all vaccine brands combined):
- One dose: 52% reduced risk of hospitalization compared to unvaccinated.
- Two doses: 72% reduction within 24 weeks of the second dose.
- Two doses (longer term): 52% reduced risk over 24 weeks of the second dose.
- Three doses: 88% reduced risk two weeks after the third shot.
For symptomatic disease (all vaccine brands combined):
- One dose: 26% reduction of risk of catching symptomatic COVID-19 within four weeks of the first dose.
- Two doses: 18% reduction within 24 weeks of the second dose.
- Two doses (longer term): 2% reduction over 24 weeks of the second dose.
- Three doses: 63% reduced risk two weeks after the third shot.
Since the data was from the UK it isn’t totally applicable to the US, which uses a different set of vaccines.
Most older people in the UK were given the AstraZeneca vaccine, which the US hasn’t used. The UK never used the single-shot Johnson & Johnson vaccine. Both countries use the Pfizer and Moderna vaccines, and the UK is using those two exclusively in its booster rollout.
The findings appear to confirm that vaccination and boosters are an effective tool against Omicron. The variant is sweeping the world, and risks pushing health systems to the “brink of collapse,” the World Health Organization recently said.
It is not clear how long booster protection will last. The UKHSA previously reported that protection against symptomatic disease dropped after 10 weeks —from 70% to 45% — after a Pfizer booster among those who had already taken two Pfizer doses.