Booster jabs could provide up to 80 per cent protection against the Omicron variant, according to the latest study from Imperial College London.
The university’s latest report (Report 49) suggests three vaccination doses against symptomatic Omicron infection can provide between 55 and 80 per cent protection.
This is well below estimates for the Delta variant, but does suggest a strong level of protection roughly in line with initial 75 per cent estimates, and that the booster jab will prevent many people from being hospitalised this winter.
The findings slightly downgrade Thursday’s reports from the university (Report 48) which suggested the booster jab could provide up to 85 per cent protection against the Omicron variant.
Alongside reduced efficacy, Imperial College London COVID-19 response team now estimates the risk of reinfection from the Omicron variant is 5.4 times greater than the Delta variant.
It has calculated protection against reinfection by Omicron afforded by past infection may be as low as 19 per cent.
Researchers used data from the UKHSA and NHS for all positive cases confirmed by PCR tests in England between November 29 and December 11 2021.
The information suggested the variant is generally much more infectious than Delta, with the proportion of Omicron cases among all Covid-19 infections doubling every two days up to December 11.
Researchers also found no evidence of Omicron having lower severity than Delta, in contrast to reports over recent days from South Africa that the variant is potentially milder.
However, the data remains limited as the variant is relatively new, and there is typically a lag between cases recorded and subsequent hospitalisations.
Professor Neil Ferguson from Imperial College London said: “This study provides further evidence of the very substantial extent to which Omicron can evade prior immunity given by both infection or vaccination. This level of immune evasion means that Omicron poses a major, imminent threat to public health.”
Professor Azra Ghani from Imperial College London added: “Quantifying reinfection risk and vaccine effectiveness against Omicron is essential for modelling the likely future trajectory of the Omicron wave and the potential impact of vaccination and other public health interventions.”
The UK reported 93,045 Covid-19 cases on Friday – it’s highest ever daily total and a third successive record day – with 3,021 Omicron cases.