How well do vaccines protect against Omicron? What the data shows
ukhsa.blog.gov.uk
ukhsa.blog.gov.uk
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Protection against death (mortality)
Vaccine effectiveness against death (mortality) from Omicron in those aged over 50 (it is too early to produce accurate data for those aged under 50):
- After two doses: 59% after twenty-five weeks
- After a booster dose: 95% after two weeks
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Protection against severe disease requiring hospitalisation from Omicron
- After two doses of any vaccine: 25-35% protection after twenty-five weeks
- After a Pfizer booster: around 90%, dropping to around 75% after ten to fourteen weeks
- After a Moderna booster: 90-95% up to nine weeks after vaccination
Hospitalisations prevented: Latest analysis estimates the boosters alone prevented 105,600 hospitalisations in those aged 25 and over in England between December 13 2021 and February 6 2022.
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Protection against symptomatic disease (mild infection)
- After two doses of AstraZeneca: around 50% protection, waning to almost 0% from twenty weeks
- After two doses of Pfizer or Moderna: 65-75% protection, waning to around 10% by twenty-five weeks after the second dose
- After a booster dose: 65-75% protection after two to four weeks, waning to 30-40% after fifteen weeks
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Protection against infection (including asymptomatic infection)
Vaccine effectiveness against infection from Delta (including asymptomatic infection):
- After two doses of AstraZeneca: Estimated at around 50% after two months
- After two doses of Pfizer: Estimated at around 81% after two months, waning to around 46% after six months
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Prevention of transmission
Effectiveness of the vaccines against transmission of the Delta variant:
- After two doses of AstraZeneca: Estimated at 42%
- After two doses of Pfizer: Estimated at 31%
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Additional vaccine protection for those with prior infection (infection-derived immunity)
Early evidence shows that getting vaccinated after infection provides significantly higher levels of protection against reinfection. Protection against reinfection from Omicron:
- No vaccination and prior infection: Estimated at 44%
- Prior infection and three vaccine doses: Estimated at 71%
> A rapid analysis from the SIREN study showed lower protection from both vaccination and previous infection to Omicron compared to Delta, but indicated higher protection among those who had received booster vaccination.
and
> Comprehensive analysis is ongoing into exactly how much additional protection the vaccines provide against Omicron infections, but a rapid unadjusted analysis from the SIREN study indicated an increasing benefit of each vaccine dose in those with prior infection.
Note "rapid analysis" for the Omicron.
Also everyone knows many people scan articles, and it feels like the format of this article is intentionally constructed to deceive those people. I would estimate 60% of readers come away with the impression those transmission and infection reductions are for omicron. The only reason I didn't make that mistake was because I knew those numbers for omicron were super far off from what is currently understood, and so I read the article more closely that I ordinarily would an article in this format.