In one year's 3.6 million U.S. births, that is 467 chronic infections instead of 255; at 26% vaccine uptake the model projects 575.
A Mass General Brigham model in Annals of Internal Medicine followed one year of U.S. births (3.6 million) for 20 years. Against 255 chronic hepatitis B infections with a universal birth dose, it projects 303 (19% more) if the first shot waits until two months, and 467 (83% more) under the CDC's January 2026 "shared decision-making" recommendation for babies of mothers who test negative, assuming half get vaccinated at two months or later. That recommendation is not in force: Worth knowingThe optional, parent-decided timing this story models is not what is in effect: the court order restored the universal birth dose, given within 24 hours of birth. Waiting until the two-month visit does not meet it..
The real number. That is 212 more chronic infections per year of births, an increase the authors call "modest, at least in the early years." The larger gap is protection: 1.8 million 20-year-olds still susceptible under shared decision-making, against 232,000 with a birth dose.
Lower uptake. At 75% uptake of a delayed shot, the model projects 357 cases (40% more); at 26%, 575 (125% more), per MedPage Today. TIME reported these as 19% and 225%; 575 is 225% of 255.
What next. A federal appeals court heard the administration's bid to lift the stay on Oct. 6, per The Hill; 15 states have also sued over the schedule changes.
What a negative maternal test still leaves, per a 10,003-child review
- Unvaccinated children of negative-testing mothers: 6.16% infected in childhood
- Vaccinated starting at 6–8 weeks: 0.21%
- Vaccinated starting at birth: 0.05% (gap not statistically significant; sub-Saharan Africa data, not a U.S. estimate)
A bar chart of the 3 figures the story lists under "What a negative maternal test still leaves, per a 10,003-child review": Unvaccinated children of negative-testing mothers at 6.16%, Vaccinated starting at 6–8 weeks at 0.21%, Vaccinated starting at birth at 0.05%.
What a negative maternal test still leaves, per a 10,003-child review
The numbers
| Percent | Share | Note |
|---|---|---|
| Unvaccinated children of negative-testing mothers | 6.16% | infected in childhood |
| Vaccinated starting at 6–8 weeks | 0.21% | |
| Vaccinated starting at birth | 0.05% | (gap not statistically significant; sub-Saharan Africa data, not a U.S. estimate) |