statefan91 said:
You or someone else smarter than me can weigh in, but it seems strange that Pfizer went with the 3mg dose as their only true trial for those age groups, rather than different groups with different dosings like it looked like the 5-12 aged trials included. It seems like that plan has set everything back for the youngest by ~6 months at least.
In this case, dosing comes down to how the immune system reacts to an unknown pathogen in the body. With younger kids, particularly this age group, it is a question of what is the minimum dose you need for the body to manufacture the spike protein and for the immune system to react. What is the dosing level that provides the best immune response, but does so at the lowest risk of complications and severe reaction?
In this case, it appears a couple of things might have happened:
1) Pfizer may have gotten the dosing wrong, since 3mg likely did not stimulate enough of the spike protein to cause a immune response to the extent it produced antibodies and T/B cells. Your immune system matures over time and what may cause a reaction in younger kids is quite different from what will cause a reaction in older adults. There can be distinct differences for kids aged 6 months of 4 years, versus 5-12 years of age. As I understand it, the age stratification can be quite sharp. The parts of the immune system that are "online" can vary, based on the age of the person.
2) Pfizer may have planned for this to be a 3 dose vaccine all along for his age group. As you know (since you have young kids), infant vaccines are typically given in series and this is for a good reason. The immune system in very young children can forget more quickly, so it needs more reminders. For this reason, it is likely a three or even four dose vaccine schedule may be more appropriate for this age group and the current trial results seem to be showing this to be the case. I think it is likely Pfizer planned for this to be a three dose schedule and were hoping two doses would be sufficient to provide some protection. Apparently, it is not, so more doses (at 3mg) are likely going to be required. I provided the chart below as a reminder as to the multiple doses we all receive to stimulate our body's immune response. Since they already have a 3 dose trial in process, I think this is the more likely explanation.
I also believe it is critical they get the spacing of the dosing schedule right. We know now that the dosing schedule for young males receiving the mRNA vaccines is likely too tight and should be spaced out. Recommendations are now out that spacing should be 8 weeks instead of 3-4 weeks. I mentioned this a couple of months ago and it appears it finally got to a point where the recommendation was changed.
I hope this helps. I do understand the frustration, but it is important they get this right. They can not afford to put a vaccine out that provides little to no protection or one that can cause adverse side-effects, if the increase doses. There is a reason why vaccine trials are complicated and in some cases, can take years to complete.
