The arithmetic is clean and fully tabulated by agent, cancer, and sex. Some fractions are 100% by definition (cervical cancer and HPV, Kaposi's sarcoma and its herpesvirus, adult T cell leukaemia and HTLV-1). Others are estimates. H. pylori accounts for 85% of non-cardia stomach cancer and Epstein-Barr for 88% of nasopharyngeal cancer.

There are no uncertainty intervals anywhere in the paper. The authors say so plainly and explain why (too many heterogeneous inputs to combine honestly). Their stated aim is to avoid "the impression of precision." Reporting to two significant figures does help. Still, a reader sees "2.3 million" and not the range around it, which is certainly wider than the hundred thousand separating this estimate from 2018's.

Agents are also treated as acting independently and their cases summed. Where two germs share a cancer (Epstein-Barr and H. pylori in the stomach, hepatitis B and C in the liver), some double counting is possible. The authors flag the stomach overlap themselves. At most it is a few percent of the total.

Epstein-Barr rose to 260,000 cases because the team counted cancers it had not counted before, mainly the roughly 8% of stomach cancers that carry the virus (78,000 cases) and two lymphoma subtypes. The authors describe the change accurately as a result of expanded evidence.

The ledger changed. The world did not. Nearly every adult carries Epstein-Barr, and whether it drives gastric cancer on its own or works alongside H. pylori is unsettled. The authors say that too.

Low and middle income countries carry 77% of infection related cancer. Eastern Asia has the most cases (990,000, 42% of the world's total), driven by H. pylori and hepatitis B. Sub-Saharan Africa has the highest share, with a quarter of all its cancers attributable to infection, much of it HPV.

The authors note that high quality cancer registries cover about 19% of the world's population and 2% of Africa's. The region with the most striking proportion is the region with the thinnest data. The direction is not in doubt. The decimal places are.

For HPV and hepatitis B, vaccination works and the evidence is decades deep. Hepatitis C is curable with oral antivirals. Eradicating H. pylori roughly halves the risk of stomach cancer in randomized trials.

The abstract calls H. pylori test and treat "scientifically proven." For an individual, fair. As a population programme it is still being piloted in Europe, as the discussion notes, with real questions about antibiotic resistance. Epstein-Barr, the Kaposi's herpesvirus, and H. pylori together account for over a million cases with no vaccine at all.

2.3 million cases, 12%, H. pylori and HPV together above 1.5 million, 360,000 for hepatitis B, 260,000 for Epstein-Barr. All match the paper. The graphic by Amanda Montañez scales each cancer by its size and shades the share caused by infection.

Vaccines exist for HPV and hepatitis B, which account for 48% of the attributable cases. The largest cause, H. pylori, has none. Neither do Epstein-Barr or hepatitis C.

A global burden study, three quarters of it in low and middle income countries, becomes advice to an individual American reader about a shot. The body of the story is more careful and mentions screening and antibiotics. The headline is what travels. The story also links to Scientific American's coverage of the hepatitis B birth dose debate, and the headline reads as part of that argument. The vaccine advice is sound. It is just not what this paper measured.

Epstein-Barr was found in gastric carcinoma in 1990 (Burke and colleagues), and the roughly 8 to 10% figure has been stable in meta-analyses for well over a decade. The paper itself says the association has been "well established" since IARC last reviewed it in 2009. What is new is that IARC now counts it.

"Since then researchers have discovered that the Epstein-Barr virus ... is also linked to some stomach cancers and some rarer lymphomas, Clifford says." This may be a compressed paraphrase of the senior author. As written, it is wrong by about thirty years. (Small note, it is nasopharyngeal, not "nasal pharyngeal.")

The linked American Cancer Society study in JNCI (February 2026) compared women 20 to 31 before and after HPV vaccination. Nationally, cervical cancer incidence fell 27%. Four places (the District of Columbia, Rhode Island, Michigan, and Hawaii) exceeded 50%. Some states showed no progress. Each 10 point rise in vaccination tracked an 11.5% drop in incidence, adjusted for screening.

The top of the range, with "some states" doing the honest work. The national 27% is a strong number on its own and would have been the better one to lead with. The vaccine's effect on cervical cancer is not in question. Sweden showed it at the level of individual women in 2020.

HPV causes six cancers. The vaccine prevents the infection, and for cervical cancer the reduction in actual cancer is now documented in several countries.

For throat cancer, which the story names, the evidence is a reduction in oral HPV infection. Cancer outcomes will take another decade or two to show. The claim is almost certainly right. It is a prediction stated as a result.

That these strategies "remain underutilised due to societal, financial, and political barriers, particularly in settings with the greatest need."

Clifford's quote that "serious mortal diseases can be prevented with a simple population-based equality-driven jab in the arm." The jab is simple. Getting it into arms is the hard part, and it is the subject of half his own discussion section. The story's last word contradicts the paper it covers.