Question: Would you address when younger children will be eligible for the vaccine?

Answer: If I were to hazard a guess, assuming safety and efficacy results are positive (and they already seem to be so for adolescents), I would say that we are likely to be vaccinating teenagers this summer (June/July) and younger children this winter (December/January).  

Let’s start with the three vaccines currently approved for use in the US: Pfizer, Moderna, and J&J.  Pfizer is already approved for use in those ages 16+ and early this month– April 9th to be exact– the company submitted to FDA its emergency use request to expand eligibility to younger adolescents (i.e. those ages 12-15).  If FDA’s processes move at their typical clip,* and the data are compelling, I think we could expect to have emergency use authorization for those ages 12-15 in May!  Meanwhile, Moderna began its clinical trial of adolescents ages 12-17 in December and its preliminary results are expected imminently.  And in March, both Pfizer and Moderna began clinical trials to test vaccine dosage, safety, and efficacy in children ages 6 months to 11 years (for more information, see clinicaltrials.gov here and here).  It will take some time for the clinical trials to complete enrollment and have enough data/follow-up time with participants to analyze and find meaningful results.  For example, Pfizer announced its trial of adolescents ages 12-15 in October and released preliminary results six months later.  If that type of timeline holds for younger children and all goes well in the trials, I suspect that we could have a request for emergency use authorization as early as November/December 2021.  Finally, when it comes to J&J, earlier this month, the company had announced that it was planning to include adolescents in its vaccination trials moving forward.  With the recent pause, however, this expansion was put on hold, and even though the pause is lifted, it’s not clear yet whether/when the trials in adolescents will resume.      

*A bit more on “typical clip”: It generally takes several weeks for FDA to review submission materials, then convene the vaccine advisory committee, and then make a determination.  For example, Pfizer submitted its original emergency use authorization request to FDA on 20 November; the vaccine advisory committee met to discuss the submission on 10 December, and FDA granted authorization on 11 December.  Three weeks from 9 April is on/about 1 May.  Given how busy the FDA vaccine advisory committee has been this month reviewing J&J safety, it seems plausible that the timeline for the Pfizer request gets pushed a bit further out.