Today Pfizer/BioNTech announced that their data on the three-dose Covid-19 Vaccines
for children ages 6 months to under age 5 years had favorable results regarding immune response, with minimal side effects. the three-dose regimen, unlike the previously studied two-dose regimen, produced an immune response similar to that of the two-dose regimen in 18- to 25-year-olds, with a strong safety profile.
This comes at a time when Covid-19 Vaccines cases are surging in many states, with some areas of the northeast determined to be back at “high alert” levels. Most regions nationwide have lifted nearly all Covid-19 Vaccines mitigation measures, including masking and testing, and few jurisdictions have reverted to requiring either, despite the marked rise in daily case numbers as well as now in hospitalizations.
Parents of the 18 or so million children under age five years in the U.S. have been eagerly awaiting Covid-19 Vaccines approval for their children. The two-dose Pfizer vaccine regimen, where a very low dose (3 micrograms) was administered to 6-month-olds to under five-year olds, three weeks apart, did not produce a substantial enough immune response worthy of submitting to the FDA for emergency use authorization.
Instead of starting the trial over at square one with a higher dose two-dose regimen, the investigators instead chose to extend the trial with a third vaccine at the same dose. The news that this additional dose added substantial protection is reason enough to celebrate.
While the news of today’s Pfizer/BioNTech data on the three-dose Covid-19 Vaccines for the youngest age group being a success is critical, this comes nearly one month after Moderna shared its favorable two-dose Covid-19 Vaccines data for children ages 6 months to under age 6 years.
The dosing of the Moderna vaccine, an mRNA vaccine with a similar mechanism of action to the Pfizer vaccine, is much higher for all age groups. For adults (ages 18 years and up), 100 micrograms of mRNA are given per dose of Moderna vaccine. And for the youngest age group, 25 micrograms per dose are given, four weeks apart.
The adult (ages 12 years and up based on dosing) Pfizer vaccine contains 30 micrograms of mRNA and is recommended at three-week intervals for the first two doses.
The two companies’ dosing differences may explain why, in the early months of these two vaccines being rolled out, individuals having received the Moderna vaccine may have had a more robust immune response than those who received the Pfizer/BioNTech vaccine, and thereby better protection.
The Pfizer dosing ran into problems as data emerged in the 5- to 11-year-olds as well. As this age group received the bulk of their vaccines during the early stages of the massive Omicron surge back in November 2021 through January 2022, while safety profile was excellent, the response to protection from illness was not optimal.
As I covered for Forbes, the low dose 10-microgram Pfizer vaccine for this age group had minimal protection against mild illness at the height of the earliest Omicron surge this past winter. It did offer excellent protection against severe illness and hospitalization, and we are continuing to see such benefits from vaccines during the current rise in Omicron sub-variants. Children ages 5- to 11-years-old who received their second Covid vaccine five or more months ago are now encouraged to receive a booster at the same dose of 10 micrograms.
While Moderna’s Covid-19 Vaccines data for the youngest eligible group has not yet been approved for emergency use, despite its submission of trial results to the FDA on May 9, 2022. It is likely that the FDA will review both the Pfizer/BioNTech data and the Moderna data for the youngest in need of vaccines sometime in June, with the hopes for emergency use authorization of one or both of these vaccine by early this summer.
A Kaiser Family Foundation survey in January 2022 revealed that only 30% of parents with children under age five years would plan on having their child vaccinated as soon as vaccines become available. The current climate of rising cases throughout this country and many others may serve as a reminder that we are far from out of the woods in this pandemic, and the more that we can do to protect the vulnerable, including infants and young children, the better off we will all be.