A few hepatitis B virus particles amid an excess of surface proteins. Image: CDC
In the early 1970s, Ted Slavin, a hemophiliac, learned his blood was special. Over a lifetime of transfusions, he had slowly amassed a huge collection of antibodies, which are proteins produced by the immune system that attach to invaders, such as viruses and bacteria. When he started receiving transfusions in the 1950s, blood wasn’t screened for diseases, which meant that he’d been repeatedly exposed to some pathogens. His immune system manufactured large amounts of protective antibodies to battle these constant invaders, one of which was hepatitis B virus (HBV) — resulting in blood with extremely high concentrations of hepatitis B antibodies.
After sunshine and smoking, hepatitis B is the most common cause of cancer.
His physician relayed this discovery to Slavin — most doctors wouldn’t have bothered, and in fact might have surreptitiously sold his blood to researchers. Back then, scientists were at work on a hepatitis B vaccine, and hepatitis B antibodies were a hot commodity. Likewise, Slavin needed money — his medical condition precluded regular work, and treatments were costly. He contracted with labs and pharmaceutical companies to sell his antibodies directly, for as much as $10 per milliliter and up to 500 milliliters per order.
When someone has a chronic HBV infection, the virus has “hijacked” some of his or her cells, “tricking” them into manufacturing copies of the virus. A virus consists of an outer protein shell housing genetic information — the blueprint that cells follow when they produce virus copies. When hepatitis B viruses are manufactured in cells, an excess of surface proteins is produced — these waste products litter the bloodstream, and testing for their presence allows people to be diagnosed with HBV infections. These surface proteins are called antigens — and as luck (or evolution) would have it, the antibodies our immune systems produce can attach to viral antigens, helping us to keep pathogens at bay.
A virologist with a Nobel Prize under his belt, Baruch Blumberg, discovered the hepatitis B antigen when examining the blood of people infected with HBV. He developed a screening method that could determine whether or not someone had the hepatitis B antigen in their system — and a diagnostic test for HBV infection was born. Slavin contacted Blumberg, hoping to contribute to his research by giving him his special blood for free. This collaboration helped Blumberg to discover the connection between HBV and liver cancer.
Building on this research, a prolific vaccinologist named Maurice Hilleman proceeded to create one of the most controversial vaccines in history. He hypothesized that he could make an HBV vaccine by injecting patients with hepatitis B surface protein. In theory, this would be very safe, as these excess surface proteins lacked infectious viral DNA. The immune system, recognizing the surface proteins as foreign, would manufacture specially shaped antibodies, custom-made to bind to, and destroy, these proteins. Then, in the future, if the patient were infected with hepatitis B virus, the immune system could promptly deploy protective antibodies, destroying the viruses before they could do any harm.
To ensure a blood supply was brimming with hepatitis B surface proteins, Hilleman collected blood from gay men and intravenous drug users — groups known to be at risk for HBV infections. This was in the late 1970s, when HIV was silently snaking its way through these communities, unknown to medicine. In addition to the sought-after hepatitis B surface proteins, the blood samples were surely chock full of HIV. Hilleman devised a multistep process to purify this blood so that only the hepatitis B surface proteins remained. Every known virus was killed by this process, and Hilleman was confident that the vaccine was safe.
The first large-scale trials for the blood-derived vaccine were performed on gay men, considered to be an at-risk group. Later, Hilleman’s vaccine was falsely blamed for igniting the AIDS epidemic. But, as ghoulish as it might seem to manufacture a vaccine from purified blood, it was determined to have indeed been free of HIV. The purification process had destroyed all viruses — including HIV.
After 30 million doses of the original vaccine were administered, a new HBV vaccine replaced the old, blood-derived vaccine. The modern-day version, licensed by the FDA in July 1986, is a genetically engineered vaccine — in fact, it is the first genetically engineered vaccine ever made. It was developed by inserting the HBV gene that codes for the surface protein into a species of yeast called Saccharomyces cerevisiae. This allows the yeast to produce only the noninfectious surface protein, without any danger of introducing actual viral DNA into the final product.
July 28 is World Hepatitis Day. While there are several types of hepatitis viruses, HBV has infected approximately one-third of the world’s population. It’s present in vaginal fluids, semen, and blood, and can be transmitted by most sexual activities, such as vaginal or anal intercourse, as well as oral sex. HBV is also spread by exposure to infected blood, and can be passed from parent to infant during birth. To protect yourself, use latex barriers, such as condoms and dental dams, if you are sexually active. Also, don’t use unsterilized needles; don’t share hygiene items that could have blood on them, such as razors and toothbrushes; and consider being vaccinated against HBV.
While most people recover from an HBV infection completely, some people die within weeks and others develop a chronic condition. It’s estimated there are 1 million chronic HBV carriers in the United States and 300 million worldwide. They are at increased risk for liver disease, such as cirrhosis and liver cancer — HBV is the third most common cause of cancer, after the sun and smoking.
You can be screened for HBV or obtain a preventive vaccine at a Planned Parenthood health center, as well as other clinics, health departments, and private health care providers. You can find more information about HBV and the vaccine at Planned Parenthood’s website, the CDC’s website, or our blog.