How vaccine makers are adapting to mutations

A focus on the exciting potential of T-cell immunity is spurring the sector on to create a new generation of jabs

- Julia Kollewe

The speed at which scientists worked to develop the first Covid jabs was unprece-dented. Just nine months after the UK went into lockdown, 90 -year-old Margaret Kee nan officially became the first person in the world outside a trial to receive the Pfizer/BioNTech vaccine. But the virus is mutating, and the emergence of the Omicron variant last month is already focusing attention on the next generation of jabs.

So what do we know about the new Covid-19 vaccines? One change is with delivery mechanisms, such as San Francisco firm Vaxart ’s vaccine-ina-pill, and Scancell’s spring-powered injectors that pierce the skin without a needle. But the biggest development is in T-cell technology. Produced by the bone marrow, T-cells are white blood cells that form a key part of the immune system. While current vaccines mainly generate antibodies that stick to the virus and stop it infecting the body, the new vaccines prime T-cells to find and destroy infected cells, thus preventing viral replication and disease. (The current vaccines also produce a T-cell response, but to a lesser extent.)

After a recent study published in Nature, scientists say vaccines targeting a T-cell response could produce much longer-lasting immunity, and be better at fighting virus mutations. “The first-generation Covid-19 vaccines were a rapid and massive victory – far greater than we dared predict,” said Danny Altmann, a professor of immunology at Imperial College London. “But they’re only the first generation of quick wins … Moving forward there are challenges to consider.”

75% The late-stage trial efficacy rate of the Medicago-GSK jab against the Delta variant