The UK is set to pilot a fourth Covid jab modified to tackle the Omicron variant, the National Institute for Health Research (NIHR) has announced.
The new variant vaccine, developed by Moderna, will be given as a first or second booster in a clinical trial due to start this week with a ‘staggered’ launch across sites in England, Wales and Scotland.
Around 3,000 study participants recruited over the next four weeks will take part, with half randomly selected to receive the Omicron variant vaccine and the other half receiving the standard Moderna Covid vaccine.
NIHR said that the study – led by a team based at St George’s, University of London – is one of the world’s first assessing the effectiveness of a fourth Covid jab dose, although it is also recruiting those who have not yet received their first booster.
The trial, lasting up to 13 months, will assess both immune response and the safety of the variant jab.
Eligible participants must not have tested positive for Covid since the beginning of November 2021 or had ‘significant exposure’ to anyone testing positive within the past 14 days and must have had their last vaccine at least three months prior to joining the study, NIHR added.
They must also have received two or three doses of the Covid vaccine already, and any previous third doses must have been an mRNA vaccine such as the existing Moderna or Pfizer jab.
Volunteers will be recruited from up to 29 sites, which include Peterborough GP practice Wansford and Kings Cliffe Practice and Blackpool clinical trial centre Fylde Coast Clinical Research, based at Layton Medical Centre GP practice.
National clinical lead for the UK NIHR Covid vaccine research programme Professor Andrew Ustianowski said: ‘We have seen from the Omicron variant how some existing vaccines may protect less well against new variants, and continued research into which vaccine combinations work best is vital to help us stay protected.
‘There are currently a number of variant and multivariant targeting vaccines in development – this was always likely to be one of the next steps in Covid-19 vaccine research, however the emergence of the recent variants has brought forward this process.’
The Moderna Omicron variant vaccine will also be examined in a coinciding Omicron variant study that will compare its results with that of a standard Pfizer dose, both used as a fourth dose for those who have already had one booster, NIHR said.
Moderna said last month that neutralising antibodies against the Omicron variant declined six months after a third dose of its original Covid vaccine, although they ‘remained detectable’.
And the UK Health Security Agency’s (UKHSA) latest Covid-19 vaccination surveillance report said vaccine effectiveness against hospitalisation was 90 to 95% up to nine weeks after vaccination with a Moderna booster.
It comes as UK regulators have approved the Novavax Covid vaccine after a series of delays to the approval process, which the former chair of the UK Vaccine Taskforce has said ‘should replace’ the Moderna and Pfizer jabs next winter.
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