A "goldmine" of data published by Public Health England on Tuesday provides a look at who may need COVID-19 booster shots, the Financial Times' John Burn-Murdoch reports.

Breaking down the numbers in a series of charts, Burn-Murdoch explains that both the Pfizer-BioNTech and AstraZeneca vaccines, which are the predominant shots in the United Kingdom, have generally held up well against symptomatic coronavirus infections, hospitalizations, and deaths even as the Delta variant took over. There are indications of waning immunity over time, though the declines are more significant among older people and especially older people with underlying health conditions. 

That left Burn-Murdoch with two major takeaways. The study simultaneously suggests that "not everyone needs a booster" and that an extra dose "could make a big difference" for those with comorbidities.

That idea seems to contrast with what's happening in Israel. The country is encouraging everyone regardless of additional factors, to get a third dose of the Pfizer vaccine (and they're even preparing for the possibility of a fourth) because of more drastic signs of waning immunity. But Burn-Murdoch argues the new data backs up the theory that a longer interval between doses deployed by the U.K. sets the stage for better long-term protection than the shorter break taken by Israel and the United States.

The good news is that Israel's booster campaign is working well, so it's worth keeping an eye on what that says about maximizing vaccine efficacy going forward.