https://archive.is/njOCl

My father didn’t know it, but by the time his urine had turned dark, the color of tea, he had only a month or so to live. Until then, he had seemed fine, at most a little tired in the weeks before. This didn’t seem unusual for a young father of two kids — me, a toddler, and my brother, a kindergartner.

One of my earliest memories is of my father flicking Mentos candies high in the air so they dropped into our waiting hands, a prize for playing nicely together. We coveted those little white, minty discs. Several weeks after his symptoms began, he was hospitalized, and I spent evenings scribbling on the medical chart at the foot of his hospital bed in New Jersey, waiting for him to get well so I could catch candy from him again.

But I never did. A few days after his diagnosis, liver cancer from hepatitis B, he was dead. He was 35 years old.

Had the hepatitis B vaccine existed back when my father was a child I would not have lost a parent at such a young age, my mother left to raise us alone. Today, the vaccine is recommended for all newborns in the United States. But I worry that this lifesaving protection will soon be taken away, as the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices is expected to vote on Friday on whether to undo the recommendation.

Hepatitis B often does not cause any symptoms until it’s too late. People can carry the virus for many decades, some for their entire lives, without knowing. All that time, they can easily spread the virus — through shared toothbrushes, razors, nail clippers. It can stay contagious on surfaces for a week or longer. Chronic infection can lead to liver failure and cancer. Babies are especially vulnerable: Around 90 percent of infants who get infected with hepatitis B will become chronic carriers.

The United States has tried different hepatitis B vaccine policies. In 1981, the vaccine was offered only to high-risk groups (such as infants whose mothers had hepatitis B, intravenous drug users and people with many sexual partners), but the virus still spread because a third of people with acute disease didn’t fall into those categories. This is why, in 1991, with hepatitis B still not under control, the federal panel recommended that all infants be vaccinated against it.

My grandparents knew before the doctors did what ailed my father. They had already lost an adolescent son, my uncle, to hepatitis B.

My father was a chronic carrier, which as many as 2.4 million Americans are. Eventually, up to 40 percent will develop liver complications. Hepatitis B disproportionately affects Asian Americans, accounting for more than half of all chronic cases, even though we make up 7 percent of the U.S. population. My father was not an IV drug user, nor did he visit sex workers, despite the assumptions Health Secretary Robert F. Kennedy Jr. and his allies have made about who gets hepatitis B.

He could’ve gotten the virus when he was born. Or maybe from his brother, or his caregivers, or his friends. Nobody knows. That’s why vaccinating everyone is so important, regardless of their perceived risks.

The hepatitis B vaccine — and the current recommendation to give it at birth — is likely why, years later, as a doctor, I cannot recall caring for a patient with liver cancer caused by this virus. It was the world’s first anticancer vaccine. To think that my father’s generation may be the last to die from this devastating infection is to grasp how truly remarkable medical progress is.

Yet the Trump administration is set to make this extraordinary scientific achievement unavailable for the youngest, most vulnerable group of Americans. If the C.D.C. advisory committee votes to change the guidelines, even if parents request the shot, health insurance may not be required to pay for it. (Perhaps some insurers will cover it, recognizing that a central tenet of medicine is prevention.)

Disease screening and surveillance might help catch some people infected with hepatitis B before they show symptoms. Drugs can suppress virus levels, though unlike with hepatitis C, there is no cure — and why manage a condition with lifelong medications when it can be prevented outright?

Even surveillance in this country is now shaky: The federal government in April shut down the C.D.C.’s hepatitis lab, which is essential in testing and monitoring hepatitis viruses, only to scramble to rehire the laid-off workers two months later — but not before the response to a hepatitis C outbreak was hampered.

I remember running around my father’s funeral, darting around the adults who wept as they patted my brother and me with sympathy I couldn’t yet comprehend. Recently, my mother asked me why a vaccine that can save families so much suffering would not be immediately offered to every child. I heard the urgency in her voice, but I could not come up with a good answer.

Americans are on track not to have to worry about hepatitis B. But if the committee decides to derail our trajectory, I fear I will meet patients and their families shattered by it in the years to come. And when I do, I will tell them I understand, that I too lost someone to this disease. The cruel difference is that, for them, the science to prevent it will have been there all along.

The Virus That Took My Father Could Become a Greater Threat