The UK’s widespread and effective vaccination program was what enabled the country to exit the pandemic and return to normal life. However, a major challenge that still faces the UK’s public health post-COVID has been the emergence of variants of the virus. That’s one of the many issues that the UK Health Security Agency (UKHSA) aims to address. They work to improve public health nationally and globally, partnering with academia and industry to do so.
Within the UKHSA, the Vaccine Development and Evaluation Centre (VDEC) specifically deals with the many variants in the wake of the COVID-19 pandemic. VDEC supports the entire vaccine life cycle from discovery to post-licensure. Sue Charlton, Head of Clinical Evaluation at VDEC, described the emergence of new COVID-19 variants as a “constant challenge”. To combat this challenge, the Centre monitor and analyse new variants like XBB and BA2.86 for their impact on vaccine efficacy.
Charlton noted that since the end of the pandemic and consequently the end of mass testing, lower levels of sequencing have meant it is harder to accurately assess the prevalence of variants. Nevertheless, UKHSA continues to analyse samples to inform about emerging risks. To do this, the Agency uses live virus neutralisation assays to quickly assess the protection vaccines offer against new variants. UKHSA obtains clinical swabs from which, they can isolate and characterise the virus.
Then Charlton outlined some of the studies that show varying degrees of vaccine efficacy against different variants, with some vaccines like Pfizer's bivalent and Sanofi's monovalent showing significant neutralizing titers against recent variants. UKHSA continuously optimises its assays to keep up with emerging variants, ensuring accurate and timely data for vaccine evaluation.
Furthermore, the UKHSA tested Pfizer’s bivalent vaccine and HIPRA’s recombinant protein vaccine against new variants. Both vaccines maintained significant neutralising titers against those variants which indicates ongoing protection.