Pfizer had disappointing results with its first trial of COVID-19 vax for the under-5 year-olds. The youngest kids mounted an adequate response, but not the older kids, which to me says that the dose was too low. This article speculates that Pfizer will add a third minidose (3 mg, compared to the 50mg it gives to adults) for the under-5s: doing so means they don’t have to do a hard reboot on the trial, and also means they can keep the dose low. (Keeping the dose low is especially important in children whose language skills might not be very good at explaining what side effects they are feeling!)
This article talks about why we won’t be able to forget about COVID-19 after the pandemic ebbs.
The article I mentioned about about developing a vaccine for the under-5s is really good. Really, you should go read it.