Hepatitis B Vaccine: The Importance of the Birth Dose

babiesDid you know that Saturday kicked off National Infant Immunization Week, which is part of a worldwide observance that shines the spotlight on the importance of vaccination? Most of us think of infant immunization as a tool to protect babies from childhood illnesses like chickenpox and whooping cough. But did you know that one infant immunization protects them from cancer later in life?

Globally, hepatitis B virus (HBV) is one of the top causes of cancer. Every year, it kills more than three-quarters of a million people worldwide. An HBV infection might be defeated by the immune system, but when it’s not, it can become a chronic infection. And chronic infections can lead to serious health outcomes, including cirrhosis and liver cancer. The younger you are, the less likely you’ll be able to fight off an HBV infection — 90 percent of infants infected with HBV will develop chronic infections, and 25 percent of them will go on to die prematurely after developing liver disease. Compare that to 2 to 6 percent of infected adults who will develop chronic infections.


Because infants are so vulnerable to developing chronic infections, vaccinating them against hepatitis B at birth makes sense.


Most people think of hepatitis as a bloodborne disease, and it is spread very efficiently when IV drug users share needles, during needle-stick accidents and other occupational injuries, or by using contaminated piercing needles, tattoo equipment, or acupuncture needles. Even sharing items like razors, toothbrushes, and nail clippers can do it, as the virus can survive outside of the human body for a week. HBV can also be spread by sexual contact, including vaginal and anal sex.

Lastly, babies and children can be at risk as the virus can be transmitted from mother to infant during birth, and during early childhood when risk of chronic infection is high. A significant number of people with chronic infections acquired them during early childhood, but we don’t know exactly how they got them, as their parents and other household contacts were negative for the virus or its antibodies. Since infants and children are at the highest risk for developing chronic infections, focusing on that population for prevention is very important.

Luckily, there’s a vaccine. Continue reading

Teen Talk: Gardasil, a Shot of Prevention

pink vaccine cartoonOne of my least-favorite medical memories must have happened when I was 5 years old, give or take. All I remember is that I was very small, surrounded on all sides by my mom, my pediatrician, and a nurse, and shrinking into a corner as the nurse came at me with a needle. I was squirming and protesting and cringing, but she grabbed my arm and pierced it with a syringe, quick as lightning. Before I could howl in protest, it was over.


Arm yourself against genital warts with Gardasil!


But here’s the thing: It hurt. A lot. And for days afterward, I went about my business feeling as if I had been punched in the arm. When I complained to my mom about how sore I was, she said that my muscles were completely tensed up, and shots hurt more when your muscles are tense. That fact only compounded my annoyance — why had that mean old nurse pricked me at the height of my freakout? If someone had just explained it to me, maybe I could have calmed down enough to relax my muscles and minimize the pain.

That incident made a mark on me, and once I hit adulthood I saw no reason to continue inviting the painful sting of immunization if I didn’t have to. It wasn’t until vaccine-preventable diseases like pertussis and measles started making a comeback that I had to admit to myself that avoiding immunization wasn’t anything to be proud of, and I started getting all my booster shots and yearly influenza vaccinations. Continue reading

Book Club: The Origins of AIDS

The Origins of AIDS
By Jacques Pepin

Cambridge University Press, 2011

Most sexually transmitted diesases go back thousands of years. Gonorrhea, for example, was first described by a Greek physician in A.D. 150, and pubic lice have been evolving right along with us since before we became Homo sapiens. This might have been one reason why it was such a shock when a strange new virus came to our attention in the early 1980s. We soon discovered that it was transmitted sexually and through infected blood, but where did it come from?


We have intriguing evidence that HIV as we know it has been in existence since at least the 1930s.


HIV has been around since before the 1980s, though it remained unnoticed and unidentified by medical science. The earliest confirmed case of HIV was in 1959, the proof found in a sample of blood from the Belgian Congo, saved in a freezer for decades and later analyzed for the virus. Other early cases of HIV infection that have retrospectively been confirmed include that of a Norwegian sailor, who must have been infected while visiting African ports in the early 1960s. He, his wife, and his child (who was apparently congenitally infected) all died in 1976, and their tissues were tested 12 years later and found positive for HIV.

Jacques Pepin — a professor and microbiologist, not to be confused with the chef of the same name — does some serious detective work to find the most plausible explanation for HIV’s origins. While he doesn’t skimp on the science, the story of AIDS’ origins can’t be told without getting into the history of Europe’s colonization of Africa in the 20th century. This period, followed by the era of post-colonization, found many societies in upheaval. Urbanization, unemployment, and migration facilitated the spread of HIV in Africa during much of the 1900s, and once it left the continent it was able to hitch a ride from host to host, traveling the world. Continue reading