There are signs that the latest wave of Covid infections may have peaked in children and younger adults, according to scientists tracking the outbreak.
But rates in those older groups most vulnerable to severe disease are continuing to increase in England.
RESULTS Of 1050 eligible HCW, 154 and 120 were enrolled to receive BNT162b2 and mRNA1273, respectively, and compared to 426 age-matched controls. Recipients of both vaccine types had a ∼9-10-fold increase in IgG and neutralizing titers within 2 weeks of vaccination and an 8-fold increase in live Omicron VOC neutralization, restoring titers to those measured after the third vaccine dose. Breakthrough infections were common, mostly very mild, yet, with high viral loads. Vaccine efficacy against infection was 30% (95%CI:-9% to 55%) and 11% (95%CI:-43% to +43%) for BNT162b2 and mRNA1273, respectively. Local and systemic adverse reactions were reported in 80% and 40%, respectively.
CONCLUSIONS The fourth COVID-19 mRNA dose restores antibody titers to peak post-third dose titers. Low efficacy in preventing mild or asymptomatic Omicron infections and the infectious potential of breakthrough cases raise the urgency of next generation vaccine development.
Covid was not the underlying cause of death in nearly a quarter of virus-related fatalities last week, official figures suggest.
The most up-to-date Office for National Statistics figures showed there were 922 deaths registered in England and Wales mentioned coronavirus on the death certificate in the week to January 7. Of them, Covid was not ruled to be the primary reason for the death in 210 cases, or 23 per cent — although it may have been a contributing factor.
For comparison, the share of deaths not primarily due to the virus stood at around 16 per cent when Omicron first arrived in the UK. With the Alpha wave last January, before the country embarked on its historic vaccination drive, the proportion was about 10 per cent.
The rise of the milder strain has led to a similar pattern emerging in hospitals, where nearly half of virus inpatients are not primarily needing treatment for the infection — compared to about 25 per cent with Delta.
Data on confirmed Covid cases in England show how the Omicron variant is already taking hold in the country
Proportion of confirmed positive tests that didn’t detect the spike protein increased from 0.1% to 0.3%
One scientist said it equates around 60 more cases with hallmark than usual, suggesting Omicron infections
Comes as R rate spirals from less than one to 3.5 in South Africa’s Omicron epicentre Gauteng province
Lead UK epidemiologist says Omicron infections likely appear mild because of immunity from past infections
WHO officials suggested on Thursday that Covid cases were milder in those who caught the Omicron strain
Levels of antibodies in the blood of vaccinated people that are able to recognise and fight the new SARS-CoV-2 Delta variant first discovered in India (B.1.617.2) are on average lower than those against previously circulating variants in the UK, according to new laboratory data from the Francis Crick Institute and the National Institute for Health Research (NIHR) UCLH Biomedical Research Centre, published today (Thursday) as a Research letter in The Lancet.
The results also show that levels of these antibodies are lower with increasing age and that levels decline over time, providing additional evidence in support of plans to deliver a vaccination boost to vulnerable people in the Autumn.