UK expert warns first set of Covid-19 vaccines likely to be 'imperfect'

London, Oct. 28 (PTI): The first set of Covid-19 vaccines that clear clinical trials for rollout to combat the deadly virus are likely to be imperfect and might not work equally for everyone, the chief of the UK government's Vaccine Taskforce has warned.

Kate Bingham, Chair of the UK's Vaccine Taskforce set up earlier this year to coordinate global efforts in search of a viable vaccine against the novel coronavirus, said it is important to manage expectations as the early discoveries are unlikely to prove the "silver bullet" that the world is hoping for to get to grips with the pandemic.

"The first generation of vaccines is likely to be imperfect, and we should be prepared that they might not prevent infection but rather reduce symptoms, and, even then, might not work for everyone or for long, Bingham writes in an article for the medical journal 'The Lancet' this week.

Highlighting that the UK is at the "forefront" of a huge international effort to develop clinically safe and effective vaccines, she also struck a note of caution that there are no guarantees that a successful vaccine will be found at all.

"No vaccine in the history of medicine has been as eagerly anticipated as that to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19). Vaccination is widely regarded as the only true exit strategy from the pandemic that is currently spreading globally. However, we do not know that we will ever have a vaccine at all. It is important to guard against complacency and over-optimism," she writes.

Bingham explains that in the long-term it may be the case that we require different kinds of vaccines for different sets of the global population as the immunity levels vary widely within age groups.

Therefore, the life sciences expert said that the UK's strategy has been to build a diverse portfolio across different formats to have the greatest chance of providing a safe and effective vaccine, "recognising that many, and possibly all, of these vaccines could fail".

The UK's Vaccine Taskforce has secured access to six vaccines, from more than 240 vaccines in development, across different formats, from adenoviral vectors to whole inactivated viral vaccines.

The most advanced vaccines, such as those developed by Oxford University and AstraZeneca, BioNTech and Pfizer, and Janssen, are based on novel formats for which the taskforce said the initial immunogenicity and safety data seems encouraging.

Vaccines based on frequently used vaccine formats, such as adjuvanted protein vaccines developed by Novavax, and by GSK and Sanofi, and inactivated whole viruses developed by Valneva, will not be available until late in 2021.

The UK is committed to ensuring that everyone at risk of SARS-CoV-2 infection, anywhere in the world, has access to a safe and effective vaccine, said Bingham.