This website is intended for healthcare professionals only.

Hospital Healthcare Europe
Hospital Healthcare Europe

Press Releases

Take a look at a selection of our recent media coverage:

Third booster sera samples have reduced neutralisation against Omicron COVID-19 variant

22nd December 2021

Third booster sera samples have been found to produce a four- six-fold decrease in neutralisation when tested against the Omicron variant

In a laboratory-based study, third booster sera samples from patients have been shown to produce a four to six-fold reduction in neutralisation against the Omicron COVID-19 variant. This was the finding of a preprint study by researchers from the Aaron Diamond AIDS Research Center, New York, US.

The Omicron COVID-19 variant (B.1.1.529) was first identified in southern Africa and appears to have a high level of transmissibility and will likely cause outbreaks across the globe. A concern with this particular variant is that it contains more than 30 mutations,15 of which are present in the receptor-binding domain region which is the target for neutralising antibodies produced in response to vaccination. It is therefore possible that the Omicron might lead to an increased level of infection despite vaccination although current opinion is that this could be mitigated by a third booster sera sample.

In the absence of clinical data, the US team sought to better understand the extent to which the Omicron variant is able to evade antibody neutralisation, by testing the activity of serum collected from a number of different patient samples. Initially the team created an Omicron pseudovirus and tested this against 10 sera samples collected from the Spring of 2020, which were likely to have been infected with the wild-type (original) COVID-19 virus. While there was a robust response to the wild-type, there was a greater than 32-fold reduction against Omicron and only two samples produced antibody titres above the limit of detection.

Vaccinated samples

The team then turned their attention to both fully vaccinated and third booster sera (TBS) samples. For the two mRNA-based vaccines, BNT162b2 and mRNA-1273, there was a >21-fold decrease in ID50 and > 8.6-fold decrease in boosted sera samples. For the other vaccines, Ad26.COV2.S and ChAdOx1, all samples produced antibody titres below the limit of detection apart from two samples for which the individual had a history of a prior infection.

Using 15 third booster sera samples obtained from BNT162b2 (13) and mRNA-1273, the researchers discovered that although each of these third booster sera produced antibody titres above the limit, there was a mean 6.5-fold drop compared to the wild-type.

Using authenticated Omicron isolates and samples from BNT162b2 and mRNA-1273, there was a greater than 6-fold drop in titres for fully vaccinated and a greater than 4.1-fold drop for boosted samples.

Finally, testing sera with monoclonal antibodies, the researchers found that all four combinations of monoclonal antibodies in clinical use lost substantial activity against Omicron.

Although this was a laboratory-based study and might not be replicated in clinical practice, the authors believed that COVID-19 is potentially only a mutation or two away from being resistant to current antibodies and that it was important to devise strategies that anticipate the evolutional direction of the virus and that future work should focus on the development of agents targeting conserved parts of the virus.


Liu L et al. Striking Antibody Evasion Manifested by the Omicron Variant of SARS-CoV-2 BioRxiv 2021

Regdanvimab recommended as a treatment for COVID-19 by the CHMP

12th November 2021

The CHMP has issued a positive scientific opinion recommending marketing authorisation for regdanvimab (CT-P59), a monoclonal antibody treatment for adults with COVID-19 who do not require supplemental oxygen and who are at increased risk of progressing to severe COVID-19.

The CHMP positive opinion for regdanvimab marks the first time a monoclonal antibody treatment for COVID-19 has received a recommendation for marketing authorisation from the European Medicines Agency (EMA). 

The positive CHMP opinion was supported by data from the global Phase III clinical trial in which Celltrion enrolled more than 1315 people to evaluate the efficacy and safety of regdanvimab in 13 countries including the US, Spain, and Romania. Data showed regdanvimab significantly reduced the risk of COVID-19 related hospitalisation or death by 72% for patients at high-risk of progressing to severe COVID-19.

Rolling review of regdanvimab had been initiated by the EMA in February 2021 and the announcement of the CHMP positive opinion for regdanvimab follows the submission of a marketing authorisation application to the EMA seeking approval of regdanvimab in October 2021.

“The primary benefits of monoclonal antibodies are their high specificity and safety – they are highly specific for a single target, so these monoclonal antibodies rarely cause undesirable side effects,” said Oana Sandulescu, MD, PhD, Associate Professor of Infectious Diseases at the Carol Davila University of Medicine and Pharmacy in Romania. “An infusion of an hour of monoclonal antibodies like regdanvimab can ease COVID-19 symptoms and reduce complications in recently diagnosed, non-hospitalised people at high risk, and thus plays an important role in preventing further spread of the virus.”