system
Given the following post, respond as if you're commenting on Reddit:
human
How viable is the UK's decision to leave 3 months between vaccine doses to attempt to vaccinate more people rather than committing to the original plan of 21 days between doses?

Unsure if the wording is right in my title. I'm wondering if this firstly, will in fact mean more people are vaccinated sooner. Secondly, will the second dose of the vaccine be as effective when given 3 months after the first dose than it would be 21 days after.
gpt
I get it. Herd immunity, where the virus dies out because so many people are immune that the virus has nobody left to infect, is pretty far off right now. So there is no broad social benefit to giving 2 doses to the same person to make them 95% protected.   


On the other hand, one dose of the vaccine is about 62% effective. That means that about 62% of people won't get the virus if exposed. But even if you do get infected and develop symptoms, the likelihood of developing severe illness is drastically reduced.   


If you only have, say, 100 doses, it is better to have 62 people immune and 38 somewhat protected against severe illness, than 50 of them almost totally immune but the rest totally unprotected.