Breaking News: Pfizer-BioNTech's Covid-19 vaccine succeeds in children ages 6 months to 5 years. At last.
It’s time to vaccinate our under-fives and now we've got options.
In 2021, I wrote that the pandemic could not end until we had a pediatric vaccine. So, when Pfizer-BioNTech’s Covid-19 vaccine trial for children ages 6 months to 5 years failed to meet its pre-specified goals, I was disappointed. Publicly. Based on earlier phases of the study, scientists had chosen a 2-dose 3-microgram series for its phase 3 trial, 33% of the total dose children 5-11 received, and just 10% of the total dose in the adult series. Unfortunately, that strategy just did not succeed. In January, I came right out and said that we would not vaccinate our then 3-year-old (and now 4-year-old) child with Pfizer-BioNTech’s Covid-19 vaccine until the data were solid. And at that time, they simply weren’t.
Now they are.
With the caveat that we’ve only been given a few pieces of data via a press release (albeit these press releases have been good indicators of what larger subsequent data readouts would eventually say), my first impression of Pfizer-BioNTech’s new data for the youngest children is very positive.
Pfizer-BioNTech now says that its clinical trial has met its goals; a 3-dose 3-microgram series (with a 3rd dose given 2 months after the first 2 doses), elicited similar antibody responses as observed in participants ages 16-25 and had an excellent safety profile. This strongly implies that vaccinated children will have ample protection against severe disease if infected with SARS-CoV-2. Like the earlier successful Moderna trial, the latest Pfizer-BioNTech data reflect the Omicron period. All told, these numbers are exactly the kinds of signals we wanted to see.
The press release also indicates that the vaccine was 80% effective against symptomatic Covid-19, although that finding is a very early one, and does not reflect adequate data such that we can be confident in that number. (Researchers decided they would do an analysis after 21 cases of Covid-19 occurred in the trial. So far there have only been 10 cases. So Pfizer-BioNTech has jumped the gun a bit here which means the 80% number is highly likely to change).
Page 1 of Pfizer-BioNTech's press release describing data from its 3-dose series for its Covid-19 vaccine for children ages 6 months to 5 years.
Page 2 of Pfizer-BioNTech's press release describing data from its 3-dose series for its Covid-19 vaccine for children ages 6 months to 5 years.
At this point, though, it’s time to move forward. Assuming that Pfizer and Moderna’s vaccines are as safe and effective as their respective press releases indicate, the US Food and Drug Administration should authorize both Moderna’s and Pfizer-BioNTech’s vaccine for the youngest children as soon as possible. That looks to be June.
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Can we talk about the timing of this announcement? I’m not a conspiracy theorist in the least, but the timing of Pfizer-BioNTech’s data drop is absolutely classic. Many observers wondered whether the relatively long lag between Moderna's initial data readout (March 23rd) and the scheduling of an FDA meeting (June 8, 21, 22) to decide whether to grant emergency use authorization was in part to wait for the release of Pfizer-BioNTech’s data; this would allow FDA scientists to analyze the two options side-by-side. The timing of today’s press release—just a couple of weeks before the FDA’s first opportunity to assess Moderna’s application—will do little to squash that speculation. I’ve heard different explanations for why the lag between Moderna’s press release and an FDA vote was longer than that of Pfizer-BioNTech’s previous pediatric authorization (for children ages 5-11), including that the latter already had had data for 12-to-17-year-olds vetted at the agency. Whether that’s the real reason, I can’t say.
Regardless, it’s clear that the FDA won’t move any faster on Moderna now. And as long as we have to wait a few more weeks anyway, it'll be nice for parents to have options.
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Sometimes, however, choices can make things harder for consumers, not easier. If the option were Pfizer-BioNTech or nothing (or Moderna or nothing), my recommendation would be straightforward: get vaccinated with whatever is available.
But parents will now likely be facing a choice: a 2-dose Moderna series that had lower efficacy (around 40%) against symptomatic infection after 1 month or a 3-dose Pfizer-BioNTech series that (so far) appears to have had a higher efficacy (around 80%) against symptomatic infection after more than 3 months.
And that’s really the pro-con that parents will be considering, at least for now. Some will want the more immediate protection (after a month) offered by Moderna. Others will be seduced by Pfizer-BioNTech’s higher apparent efficacy, even if that means waiting for over 3 months to get to that level of protection. (The degree of protection young children may have after the first 2 doses of Pfizer-BioNTech is probably quite low given what we know, making that 3rd dose crucial for this dose and age group.) Again, it's crucial to note that the 80% efficacy data from today's Pfizer-BioNTech announcement is very, very preliminary, and it's based on a small number of cases. I suspect most people may not recognize this subtlety because media headlines are certain to gravitate towards that 80% figure. But it's so early that this could just be noise. We don't actually know if the difference between 2-dose Moderna and 3-dose Pfizer-BioNTech in preventing symptomatic Covid-19 reflects something real, or is just luck. Meanwhile, immune response antibody data for both Moderna and Pfizer-BioNTech look rock solid.
In addition, we don't yet know what a 3rd dose of Moderna will do—something being studied now. Ultimately, though, what many parents want to know is that if their child gets infected, they won't suffer any long-term consequences. For the time being, I think it's reasonable to say that both options will provide parents that peace of mind they've wanted for over 2 years.
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Personally, if I had to choose between Pfizer-BioNTech and Moderna based on what I know today for my child, I might actually choose Moderna, even though Moderna's 2-dose efficacy against symptomatic Covid-19 was apparently lower than the early analysis from Pfizer's 3-dose series. I'm just so done worrying about my child having a bad outcome (albeit that’s relatively unlikely). It will be nice to have that weight off my shoulders within a month of the vaccine’s authorization—which only the Moderna option will offer. So even if 3-dose Pfizer-BioNTech ultimately ends up holding up as better—which we still don't know—some parents will prefer to get 2 doses of Moderna and be done worrying about the worst-case scenarios.
Others may be wowed by Pfizer-BioNTech's better early efficacy numbers (despite my admonitions above about the data regarding protection against infection being too early to be reliable) and opt for that, even if reaching that level of protection will take 2 months or more to attain.
Of course, Moderna will eventually have a 3rd dose option as well and if the data support it, that option might be even better than Pfizer-BioNTech’s. In fact, when that happens, we’ll be far better able to compare these two options fairly. Right now, it's a bit apples-to-oranges. But at least both options are looking good. Finally!
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