Valneva has reported additional data from a small exploratory study of its COVID-19 booster vaccine, VLA2001, for people aged 18 years and older.
A subset of participants in the VLA2001-307 study received a booster dose of VLA2001 following two or three doses of an mRNA COVID-19 vaccine, with or without break-through infection.
The booster was well tolerated in those who had previously had a Pfizer/BioNTech or Moderna COVID-19 vaccine, and the company said this confirms the favourable safety profile of its booster from all studies, including in both homologous or heterologous settings.
In this latest study, however, an additional booster dose of VLA2001 only marginally increased the neutralising antibody response.
Juan Carlos Jaramillo, Valneva’s chief medical officer, said: “While these latest booster results are not aligned with the encouraging homologous and heterologous booster results seen previously, we are pleased to once again confirm the favourable safety and tolerability profile of VLA2001, which was important for European Medicines Agency (EMA) and Medicines and Healthcare products Regulatory Agency (MHRA) approval.”
In August 2022, Valneva reported positive heterologous booster results following primary vaccination with an AstraZeneca (AZ) COVID-19 vaccine, as well as positive homologous booster results at the end of December 2021.
The company said it is currently seeking regulatory approval for VLA2001 both as a homologous booster and heterologous booster for those who had already had an AZ vaccine.
VLA2001 is a purified, inactivated and adjuvanted whole virus SARS-CoV-2 vaccine that uses a similar approach to the flu vaccine.
Following administration of VLA2001, the spike protein of SARS-CoV-2 and other viral surface antigens stimulate both neutralising and other functional binding antibodies, as well as cellular immune responses directed against the spike and other surface proteins, which are thought to help protect against COVID-19.
VLA2001 was the first COVID-19 vaccine to receive a standard marketing authorisation in Europe and the only whole virus, inactivated, adjuvanted COVID-19 vaccine to receive marketing authorisation in Europe for use as primary vaccination in individuals aged 18 to 50 years.
The vaccine company also announced positive results last month for its chikungunya vaccine candidate, VLA1553, which demonstrated promising 12-month antibody persistence results after a single dose.
The trial, which Valneva said will monitor antibody persistence on an annual basis for at least five years, showed that 99% of participants retained neutralising antibody levels above the seroresponse threshold of 150 12 months after the single-dose vaccination.