Is skipping J&J and waiting (a little while) for Pfizer/Moderna wiser?

2 points by pardner 5 years ago | 3 comments

It seems to me that the official recommendation "the best vaccine is the one they offer you first" ignores one crucial consideration that might make a better decision for some individuals to be "skip the J&J if I can get Pfizer/Moderna by waiting a 'reasonably short' time".

That crucial consideration is: the health of un-vaccinated people around me. If there are people around me who will not be eligible for a vaccine for months, THEY seem to be better protected - from me - if I choose either of the two higher-efficacy vaccines (within a "reasonably short" incremental timeframe).

Based on the data we have so far it looks like I am about 5x more likely to get infected after J&J compared to Pfizer/Moderna, based on J&J's lower efficacy of about 75% vs 95%.

Even though J&J would protect ME from serious complications, if I get J&J and then get infected I am contagious, and therefore I am a risk to still-unvaccinated people around to me who still have normal risk for serious/fatal complication.

So if I can expect to have Moderna or Pfizer available within a "reasonably short" time frame, I'll wait for one of those higher-efficacy vaccines in order to better ALSO protect the unvaccinated people around me.

But the hard part is deciding what is a "reasonably short" timeframe? There is obviously a non-zero incremental risk from waiting, so that short-term risk (to me and mine) needs to be balanced against the longer-term risk (to others) from my rushing to accept a less efficacious vaccine sooner.

Using the current daily covid infection rate divided by the population as a rough, quick, back-of-envelope guesstimate for "incremental daily risk of infection" on the order of 0.015%.

Pretty big assumptions. But unless my reasoning is way off, I'll be willing to wait an extra 10-14 days for Pfizer/Moderna (vs J&J) with the goal of lower net risk to the unvaccinated people around me.

geophile 5 years ago |

The efficacy rates are not comparable. My understanding is that, compared to the Moderna and Pfizer vaccines, J&J was tested on a more diverse population with respect to age and location, and also tested later, so that it faced more variants of the virus.

Get whatever vaccine you can.

(Disclaimer: I got the J&J vaccine two weeks ago.)

19g 5 years ago | |

I saw this video, which illustrates what you pretty much stated:

https://www.youtube.com/watch?v=K3odScka55A

I actually wish I got the JnJ vaccine (I got the first dose of the Pfizer vaccine last week).

pardner 5 years ago | | |

Best general explanation I've seen so far, thanks for posting the link.

Unfortunately, it still completely sidesteps any discussion of the relative risk of a vaccinated person (who is protected from a severe infection themselves) still a) getting infected and b) causing a severe case in someone else who is not yet vaccinated.

So while "efficacy" may not be relevant on one dimension (MY chances of severe infection) it still seems important in another dimension (the chances of ME nonetheless getting infected then giving a severe case to someone else).