Chat about Novel Coronavirus - 2019-nCoV - COVID-19

My understanding is you build up immunity around 2 weeks after the second dose. However, 1 in 20 don't. Is it worth it? (IANAD)

Still not worth it as it doesn’t mean she won’t 100% catch it.

Also there’s still a risk of you moving the virus to their destination and potentially infecting others.

You could come round if you’re vaccinated as well.

Not trying to be snarky, but when the rules say you can. Vaccine doesn’t stop transmission, just significantly reduces chances of getting severe disease requiring hospitalisation, and as others have said travelling to/from etc increases risk of transmission. Until enough of the population has had the vaccination to get proper herd immunity and we don’t run the risk of shafting the NHS again, we need to adhere by prevailing precautions. In terms of personal risk to your grandma, she should get decent partial protection (50-60%) AFAIK after about 7-10 days after first dose, and then maximum (but not complete) protection from severe disease roughly the same time again after second dose.

when can I go round for a cup of tea?

It's complicated. My Dad got the Pfzier vaccine yesterday (mid 70s but extremely clinically vulnerable). Different to the Oxford vaccine, but it will take 12 days to even start doing anything, a few weeks after that it should typically be 52% effective.

He's due to have his second dose on the 2nd April, a week after that it would typically be 95% effective.

(Source: https://www.bmj.com/content/371/bmj.m4826#:~:text=The%20study%2C%20published%20in%20the,cases%20in%20the%20placebo%20group)

All this aside, the vaccinated will have to follow the same rules as everyone else because the advice after you've had the first jab is to act like you've not had it, then even when you've had the second you may still spread it.

So although my Dad will be as safe as he's going to be from 9th April we've got to hope that infection rates will have dropped by then and social distancing rules relaxed.