Vaccines
The National Advisory Committee on Immunization recommends a third shot for various types of immunocompromised people.
From this tweet, using data from Public Health England:
From this tweet, also using data from Public Health England (note that it’s a LOG scale!):
This US CDC report says that:
- the effectiveness against hospitalization was 76% for those 75 and over, and 89% for those under 75;
- Moderna was more effective (95%) than Pfizer (80%) or J&J (60%)
Yet another US CDC report says that mRNA vaxes were 87% against hospitalization — 80% for those 65 and over and 95% for those under 65%.
Variants
This US CDC report says that Delta has not changed the effectivenesses against hospitalization or against death.
Recommended Reading
This article talks about “sterilizing immunity”, immunity that is so good that you never get infected and never transmit. The article says that that basically never happens, and explains.
This article talks about “how COVID-19 hacks the immune system”.
Someone raised a question on Twitter as to why drug resistance is common, while vaccine resistance is rare. The short answer is because drugs are targeted therapeutics against gazillions of bacteria already in your body; vaccines are scattershot prophylactics to keep viruses out of your body. If you are interested there are articles here, here, here, here, and here.
This sobering article talks about the COVID-spurred rise of hospital-acquired infections (in the US, but probably widely applicable).