The miracle of the HIV-free baby
The apparent curing of a baby with HIV is a brilliant reminder of man’s capacity to defeat nature’s many menaces.
No disease in modern memory has received as much attention as AIDS. First discovered in 1982 among the homosexual population of Los Angeles and nearby Orange County, AIDS was rapidly recognised as a global pandemic.
By the middle of the 1980s, mass marketing campaigns were being run around the world warning of the dangers of HIV, the virus that causes AIDS. The people of Britain were warned, ‘Don’t Die of Ignorance’, and the warning was taken seriously. In 1989, I vividly remember our chemistry schoolteacher asking us all to stand up and take a good look at one another because in five years’ time more than one in three of us would be dead from AIDS. HIV was highly infectious and AIDS was incurable. We gulped and sat down.
Turns out my chemistry teacher was wrong about the highly infectious nature of HIV, and so were an awful lot of other people as has been extensively discussed previously on spiked (see The authorities have lied, and I am not glad, by Dr Michael Fitzpatrick). But she was also wrong to be pessimistic about what medicine might deliver for those infected with HIV. Rapid medical advances meant that HIV infection quickly transitioned from a death sentence to a chronic manageable state. In 1984, a team of scientists from the American National Cancer Institute experimented with the chemotherapy drug AZT (also known as Zidovudine) and demonstrated that it could protect immune cells from attack by the HIV virus. The drug was approved for clinical use in 1987, the fastest drug development in history. Subsequent testing proved that AZT safely prolonged the lives of patients infected with HIV, but AZT was not a cure. AZT typically delayed the onset of AIDS by two to three years.
Research into the mechanisms of HIV continued apace and many important discoveries were made, including the fact that the HIV virus battles furiously with the immune system from the moment of infection. In 1996, David Ho demonstrated that the HIV virus produces 10 billion virions (a complete viral package or replication of the virus) a day, which radically changed the way we view the immune system. Before this discovery, it was believed that the immune system could not cope with such an onslaught. Now it became clear that the immune system was continuously wiping out this barrage and could do so for several years.
This wasn’t the first time medicine has overturned a dogmatic belief about what the body can and cannot do. While AZT was being used to destroy the HIV virus in 1984, Australian researcher Barry Marshall swallowed a liquid containing the bacterium Helicobacter pylori that he had cultured from a patient with a stomach ulcer. Marshall subsequently developed an ulcer himself and thus provided critical evidence that stomach ulcers could be caused by a bacterium. Before Marshall’s experiment, nobody believed that anything, let alone bacteria, could survive in the ferociously acidic stomach. Helicobacter survives by swimming very fast through the acid and then burying itself in the stomach lining, where it does its damage. Marshall’s discovery led to ulcers being treated with a simple course of antibiotics.
Ho’s discovery also led to a new treatment for HIV infection. The nature of attack from HIV meant that continuous antiviral treatment was necessary. Thus was born highly active antiretroviral therapy (HAART) as a way of continuously blocking the replication of HIV and preventing collapse of the immune system. Like AZT before it, HAART is not a cure, but unlike AZT, HAART can hold HIV at bay potentially for life. Thus, with HAART, HIV became a lifelong but manageable infection. HAART also largely prevents sexual transmission of HIV, and the use of antiretroviral treatment in combination with AZT dramatically reduces mother-to-infant transmission of HIV during pregnancy.
It remains uncertain exactly how the HIV virus survives despite multiple attack from HAART treatment, but it appears that the virus hides in some of the patient’s resting immune cells. If treatment stops, any virus that is hiding can emerge and start replicating again. That is why HAART must be continued indefinitely and why it cannot cure HIV – or could not until very recently.
The tendency of medicine to surprise and push the boundaries of what is possible may now overturn the belief that HAART cannot amount to a cure of HIV. On Sunday, a group of scientists from Johns Hopkins University reported the case of an infant born HIV-positive and initiated on antiretroviral therapy at 30 hours of age. At 26 months of age, and without any medication for almost a year, the infant was completely free of the HIV virus. The only documented cure of HIV before was the case of the Berlin patient, Timothy Brown, who received a bone-marrow transplant from a genetically HIV-resistant donor. But bone-marrow transplantation is a difficult and life-threatening procedure, whereas antiretroviral treatment is simple and largely safe.
The idea, expressed by my chemistry teacher of old, that AIDS will strike us down because we are not smart enough to deal with the menace of nature has been dealt another blow. Medicine often reminds us that we can do great things and solve problems big and small: organ transplantation, open-heart surgery, and the eradication of smallpox were all once decried as impossible. All have been achieved.
For the 300,000 babies born with HIV every year, the breakthrough in treatment of HIV-positive infants could mean escaping the lifelong need for antiretroviral treatment with obvious implications for life expectancy and dramatic cost savings. If it can be further discovered how to flush out the hiding HIV in adults, the implications will be staggering. The zeal and creativity of scientists have transformed HIV infection from a diagnosis of certain premature death to an infection that we can control and now hope to cure.
Stuart Derbyshire is a reader in psychology at the University of Birmingham.