Valena, the French speciality vaccine company on 21st January announced in a press release results from an initial laboratory study demonstrating that serum antibodies induced by three doses of Valena's inactivated COVID-19 vaccine candidate, VLA 2001, neutralises the Omicron variant. This may turn out to be a real breakthrough and long-awaited good news.

The researchers from Valena used sera from 30 participants in the Phase 1/2 trial VLA2001-201 in a pseudo-virus assay to analyse the neutralisation of the ancestral SARS-CoV-2 virus as well as the Delta and Omicron variants. The company claimed that all 30 samples (100%) presented neutralising antibodies against the Omicron variant. The company summed up the results of their study (not yet peer-reviewed) thus (verbatim):

1. Preliminary laboratory studies demonstrate that three doses of Valena's inactivated COVID-19 vaccine candidate VLA2001 induced neutralisation of the Omicron variant (B.1.1.529 lineage).
2. 100% of tested serum samples presented neutralising antibodies against the ancestral virus and Delta variant and 87% against the Omicron variant.
3. The mean fold reduction of neutralisation relative to the ancestral virus was 2.7 fold for Delta and 16.7 fold for Omicron.

Laboratory studies

In order to assess neutralisation, the researchers pre-incubated the pseudo-virus expressing the spike(S) protein from either the ancestral SAR-CoV-2, the Delta variant or the Omicron variant with serial dilutions of individual serum samples and then used to infect target cells. They calculated neutralisation from the reduction of infection efficiency at different serum dilutions compared to a no serum control. The German Primate Centre performed the assays and analyses.

VLA 2001 as a booster

According to Valena, VLA 2001 may also be suited for boosting, as repeat booster vaccinations have been shown to work well with the whole virus inactivated vaccines. VLA 2001 consists of inactivated whole virus particles with alum and CpG 1018 as two adjuvants. This combination has consistently induced higher antibody levels in preclinical experiments than alum only formulations and shown a shift of the immune response towards Th1.CpG 1018 adjuvant. Researchers expect VLA2001 to confirm with standard cold chain requirements (2 to 8°C).

Expert comments

Reacting to the development, Dr Clive Dix former Chair of the UK Vaccine Task force said:

“This is very encouraging data and adds to the positive Phase 3 data. Hopefully this vaccine will be approved soon and should become an important vaccine in both this pandemic in countries still behind the curve and as a vaccine for boosting during the winter of 2022/23.”

As per the press release from the company quoted Juan Carlos Jaramillo, M.D., Chief Medical Officer of Valena: "We are extremely pleased with these results which confirm the potential for broad-spectrum protection of our inactivated adjuvanted whole virus vaccine and its ability to address currently circulating variants of concern. These results add to earlier findings from our Cov Compare Phase 3 trial, in which two doses of VLA 2001 given as a primary vaccination were shown to induce superior neutralising antibody levels and broad T-cell response. We continue to believe that VLA 2001 could be an important component of the fight against COVID-19, and Valena remains fully committed to bringing VLA 2001 to people who need it as soon as we can."

Advance action with regulators

The release confirmed that the company is continuing to provide data to the European Medicines Agency (EMA), the UK Medicines and Healthcare Product Regulatory Agency and the National Health Regulatory Authority in Bahrain (NHRA) as part of the rolling submissions process for initial approval of VLA 2001. The company continues to expect to complete these submissions in time to receive regulatory approvals in the first quarter of 2022. The company has received advance booking for VLA 2001 from the European Medicines Agency and the Kingdom of Bahrain.

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

Dr K S Parthasarathy is a former Secretary of the Atomic Energy Regulatory Board and a former Raja Ramanna Fellow, Department of Atomic Energy. A Ph. D. from the University of Leeds, UK, he is a medical physicist with specialisation in radiation safety and regulatory matters. He was a Research Associate at the University of Virginia Medical Centre, Charlottesville, USA. He served the International Atomic Energy Agency as an expert and member in some of its Technical and Advisory Committees.