This calculator is not medical advice. It's an attempt to organize some facts on COVID to help with family and personal decision-making. You can see more details in this newsletter post here: https://emilyoster.substack.com/p/what-can-i-do-a-calculator. A key simplification here is to ignore vaccinated people -- basically, model your interactions thinking only about the unvaccinated people in your group. To start: check out the page of assumptions. You'll want to specify how many unvaccinated people you plan to have at your gathering, their risk levels and personal risks. The values in yellow here are ones you can modify. I've allowed for up to 10 people. If you dont have that many, leave their rows blank! There are a few comments in there about how to inerpret the columns. The calculator page will then do some bilateral calculations. The last page gives you some results. I've recorded a video of me talking through an example here, in case you want to see how I'd use this... It's here
FAQ (Continually Updated):
What about partially vaccinated individuals? You could include them in here and modify their risk. Easy way to do that is to mutiply their case rates by something. Example: if you think a first dose is 80% effective, include someone but mutipliy their location case rate by 0.2 (to capture 80% reduction in risk).
Can I incorporate vaccinated individuals here? I'm not comfortable ignoring them. Of course! Easiest way to do that, just like the partially vaccinated, is to multiply their case rates by something. Example: if you think the vaccine is 90% effective, multiply their locaiton case rate by 0.1. You might also want to lower the transmission rate from them to others. You could do that by further decreasing the case rate.
What about people who have had COVID? Vaccines are still recommended for people who have had COVID, although most of our data suggests that reinfection is rare if people have antibodies. You may want to treat them as "partially vaccinated" (see above).
I'm breastfeeding. Is it like my kid is vaccinated? No. Breastmilk does have some COVID-19 antibodies (so cool!) and as a result it seems plausible/likely that there is some "passive immunity" while you are breastfeeding. However: we do not know how robust this is (certainly less than vaccine-induced immunity) and it would only last during the period of breastfeeding. My best advice is to just treat the breastfed infant as unvaccinated, to be conservative. I think the New York Times has an excellent discussion of this issue which you can find here.
Can I have edit access? No. Then it would edit for everyone! But you can download a copy and modify. If there is too much traffic it may not let you download, so try this excel version: https://drive.google.com/file/d/1-omGAxupY1aCc-XmFTe5MEWPOpmT92fM/view?usp=sharing