Pfizer to test a 3rd dose of coronavirus vaccine in young children after 2-dose regimen falls short

[Nevilledog]

https://www.washingtonpost.com/health/2021/12/17/pfizer-vaccine-young-children-third-shot/

No paywall
https://archive.ph/YuKIB

Parents will have to wait for a coronavirus vaccine for their young children after Pfizer and BioNTech announced Friday that they are modifying their clinical trial to include a third shot at least two months after the initial two-dose regimen for children under age 5.

The companies reported that two doses of the pediatric vaccine failed in 2-, 3- and 4-year-olds to trigger an immune response comparable to what was generated in teens and older adults. The vaccine did generate an adequate immune response in children 6 months to 2 years old.

If three doses are successful at triggering a protective immune response, the companies expect to submit the data to regulators in the first half of next year.

“It is important to note that this adjustment is not anticipated to meaningfully change our expectations that we would file for emergency use authorization and conditional approvals in the second quarter of 2022,” said Kathrin Jansen, head of vaccine research and development for Pfizer in a call with investors.

*snip*

[LonePirate]

1. This scourge is never going away.

[frazzled]

2. That's interesting

2, 3, and 4 year-olds don’t develop the immune response. (No mention of five year-olds, or the 6-12 group that have already been approved for vaccination, though I assume these latter have been vetted).

But 6 month to 2 years do have a response?

What is it about preschoolers, 2-4 years, that makes them fail?