Hopes of a Covid-19 vaccine breakthrough as TWO trials in the UK and US show volunteers injected with experimental jabs have signs of immunity against the disease
- UK scientists are '80 per cent' confident that a jab could be ready by September
- Trials finding that participants develop antibodies and killer T-cells to fight it
- People in the Oxford study with AstraZeneca are showing signs of immunity
- And early trials of US-made vaccine by the firm Moderna have been successful
- Mild side effects are 'a small price to pay' for protection from Covid, experts say
