For the sake of argument, let’s assume that the effectiveness of j&j and moderna/pfizer are 66% vs 95%, respectively, and this effectiveness comes in at the same time. Suppose you keep yourself to a constant risk of x per week, without factoring in vaccine protection, based on the case rates and variants in your area. If n is the number of weeks between getting the j&j vaccine vs the moderna/pfizer vaccine, and m is the number of weeks between getting the moderna/pfizer vaccine and the end of the pandemic, then you have the risk of (1-(x*.33)^(n+m)) if you get the j&j vaccine, and the risk of (1-x)^n * (1-(x*.04))^m if you get the moderna vaccine.
If I was offered the j&j vaccine tomorrow, vs the moderna vaccine I have scheduled in 3 weeks, and we assume the pandemic will be over in the first world by september 1st (20 weeks out), and my weekly (non-vaccinated risk budget) is 200 microcovids, then I would be looking at 0.132% chance of covid with j&j vs. 0.093% chance of covid with moderna/pfizer. So, it’s worth it for me to wait it out. But, if you think the pandemic will be over in half the time, then it’s 0.066% vs 0.085%, and so you should take the j&j vaccine.
For the sake of argument, let’s assume that the effectiveness of j&j and moderna/pfizer are 66% vs 95%, respectively, and this effectiveness comes in at the same time.
I think it’s important to also point out that this assumption is not true. All of these vaccines seem to have similar effectiveness for the first 3 weeks after the first dose and the major divergence happens after the second dose (and I suspect there would be a smaller divergence if we did two doses of J&J, but of course we have “no evidence” of that).
From a wanting-to-end-the-pandemic-faster perspective, my preferred solution is to get one dose of J&J now and a second dose of something else* once we inevitably “discover” that vaccine boosters work in cases that weren’t specifically studied too.
I suspect a second dose of a non-adenovirus vaccine would be more effective than a second dose of an adenovirus-based vaccine due to the risk of adenovirus immunity.
For the sake of argument, let’s assume that the effectiveness of j&j and moderna/pfizer are 66% vs 95%, respectively, and this effectiveness comes in at the same time. Suppose you keep yourself to a constant risk of
xper week, without factoring in vaccine protection, based on the case rates and variants in your area. Ifnis the number of weeks between getting the j&j vaccine vs the moderna/pfizer vaccine, andmis the number of weeks between getting the moderna/pfizer vaccine and the end of the pandemic, then you have the risk of(1-(x*.33)^(n+m))if you get the j&j vaccine, and the risk of(1-x)^n * (1-(x*.04))^mif you get the moderna vaccine.If I was offered the j&j vaccine tomorrow, vs the moderna vaccine I have scheduled in 3 weeks, and we assume the pandemic will be over in the first world by september 1st (20 weeks out), and my weekly (non-vaccinated risk budget) is 200 microcovids, then I would be looking at 0.132% chance of covid with j&j vs. 0.093% chance of covid with moderna/pfizer. So, it’s worth it for me to wait it out. But, if you think the pandemic will be over in half the time, then it’s 0.066% vs 0.085%, and so you should take the j&j vaccine.
I think it’s important to also point out that this assumption is not true. All of these vaccines seem to have similar effectiveness for the first 3 weeks after the first dose and the major divergence happens after the second dose (and I suspect there would be a smaller divergence if we did two doses of J&J, but of course we have “no evidence” of that).
From a wanting-to-end-the-pandemic-faster perspective, my preferred solution is to get one dose of J&J now and a second dose of something else* once we inevitably “discover” that vaccine boosters work in cases that weren’t specifically studied too.
I suspect a second dose of a non-adenovirus vaccine would be more effective than a second dose of an adenovirus-based vaccine due to the risk of adenovirus immunity.
There is also a risk of PEG immunity which will make one immune to lipid nanoparticle vaccine.