There's a huge focus in the US now on "breakthrough infections" - it's not a phrase I've seen much in the UK but it does a lot to explain what's happening here, and one we may start to become much more familiar with. (1/?)
Put simply, a "breakthrough" infection is one which breaks through the resistance to infection conferred by vaccination. It's what happened to @sajidjavid - double-jabbed, but still got the 'rona.
Remember: the original aim was for vaccines to reduce/eliminate the risk of death/serious illness. The fact that they ended up making the vaccinated less infectious was a very welcome bonus.
The big problem with the Delta variant is that it is more infectious. In other words, it's more likely to break through that vaccine-induced resistance. So people who have been double-jabbed can still get sick, and still pass it on to others. And are doing so in large numbers.
However, the crucial thing is that so far, the resistance to serious injury and death is still holding up. Hence cases exploding and deaths staying incredibly low compared with first/second waves.
This is the big problem for us/the US/Israel/probably everyone. The fact that Delta is more infectious/more likely to break through means it's far harder to reach herd immunity.
Rather than saying 'once eg 70% of the population have been jabbed/vaxxed then the virus just doesn't have enough people to spread to', we need that figure to be much higher - hence why even the incredible take-up we've seen may not be enough...
...and all the talk about vaccinating teenagers/kids. Because it's not just about protecting them, but reducing the pool for the virus to circulate.
As it is, it looks like - as Whitty has said - we're basically going to be living with this disease rather than crushing it. And breakthrough infections are a huge part of why.
PS To be clear, being vaccinated does very significantly reduce your risk of becoming infected, too! Just less so with Delta. But you should definitely, definitely, definitely get the jab if you haven't.
PPS And obviously waning immunity from vaccines is a potential concern, and we may all need booster shots, but that's a separate concern...
• • •
Missing some Tweet in this thread? You can try to
force a refresh
