Dr. Clare Craig points out an error by vaccines minister Nadhim Zahawi about what 60% vaccine efficacy means.
- If vaccines have 60% efficacy that does not mean that 60% cannot be infected.
- It means that if 90% of unvaccinated household contacts don’t catch it from index case, then if they were vaccinated that rises to 96%.
- Around 10% of close contacts catch it from an index case. (Source: Public Health England Technical Briefing 15)
- A vaccine with hypothetical 60% efficacy would reduce the proportion who caught it by 60% – to 4%.
- 90% would not catch it in either instance.
- 4% were protected thanks to vaccination.