Why is the HIV virus so vicious and, given that an effective vaccine was expected many years ago, why has none emerged?
A normal vaccine works by injecting non-active, or attenuated, viruses of diseases like flu and polio, which the body recognises and responds by producing antibodies, and – in the cases of attenuated viruses – T cells which multiply and actively attack the virus. The system also “remembers” the virus to give continuing immunity. Unfortunately the HIV virus goes straight in to attack the T cells, to destroy them and to use them for replication. It particularly targets the memory T cells which allow the body to prepare for future infections by knowing the old ones.
In fact the HIV replicates on entering a cell very inefficiently, producing several mutant strains. The virus, almost diabolically, alters in so many ways that neither antibodies nor T cells can cope. Our annual flu jab needs to be modified every year to deal with mutations, but the HIV works like lightning by comparison. An effective vaccine would have to be flexible enough to deal with thousands of variations of viruses, not just one.
The first attempt to get around this was to devise a vaccine which would stop the infection at source by changing the outer shell of the HIV, and preventing it from entering healthy cells. Good theory, except that it didn’t work. Following this, an attempt was made to use a vaccine which would substantially reduce the multiplication of the virus by injecting some harmless proteins present in HIV, and so allow the immune system to ready itself for attack. This would at least reduce the transmission of infection to others. But the trial of the most promising system had to be suspended when more cases of infection occurred in the vaccinated group than the group which received a placebo. A trial of a further variation gave equally poor preliminary results, and was called off in July 2008.
But of course the scientists have not given up. There are some monkeys and a few human beings who seem to have a natural control over virus limitation. This may well have to do with minor genetic changes. But studying what the changes are, and the processes through which they work, may provide the needed clues. This is one avenue of exploration. And it may be that past, abortive, attempts can be tuned to achieve greater success. Some outlandish ideas currently proposed may yield surprise answers. There is now much closer collaboration between different research institutes, which have received funding from welfare organisations, including the Bill and Melinda Gates Foundation. Remember that when you next feel like cursing Microsoft. Collaboration does not ensure success, but it improves its chances.
For the time being we have to be content with the antiretroviral drugs which control the outcome of infection, and its transmission – including the perinatal infection of the newborn. Issued in the right complex mix, regularly taken and regularly checked, they can inhibit the virus from triggering Aids over many years.
Under this regime, mortality rates during the five years after infection are the same as those in the uninfected population, although they accelerate thereafter. But drug therapies may not be easy when necessary hospital visits are required in remote areas, and the good diet required for their effective use is not always available. There is for the time being no known cure because the virus, temporarily stymied, secretly colonises many parts of the body, quietly waiting to become active again.
The major prophylactic continues to be education and good sexual morals. The problem of married couples, one of whom is infected, or both of whom are infected with different strains, remains. This raises a vexing question. While it is always possible for such a couple to abstain from intimate contact throughout their married lives, it is not a real-world solution. Apart from denying the couple a major means of expressing and developing their married love it is a particular difficulty in Third World countries. Wives may often find themselves in a position where they cannot resist marital relations, or, if they do, they are risking infidelity in their husbands – which may destroy the marriage or indirectly lead to a further spread of the virus.
One much-canvassed opinion argues that since in these cases the condom is not being used for contraception but for protection it is legitimate. Many senior Church figures including Cardinal Lustiger, Cardinal Martini, Cardinal Cottier (theologian of the papal household under John Paul II), Cardinal Danneels and Cardinal Murphy-O’Connor have all been cited in support of condoms in the context of Aids in one form or another. But the official position remains unchanged, and it is easy to see why. If a protective intention suffices, then it opens the door to protection from any other infection similarly transmitted.
More fundamentally, the teaching states that it is “absolutely required that any use whatever of marriage must retain its potential to procreate human life”. (Pope Paul VI’s italics.) The issue here is specifically not intention but the objective physical denaturing of the act within marriage. Allow intention, no matter how good, to prevail once and the whole edifice might crumble.
But no decision on this question is as yet on the horizon. For now the ox will not be pulled out of the pit on the sabbath day. After all it took a mere 359 years for the Church to repudiate formally the condemnation of Galileo. Given that this is a matter of life and death a somewhat shorter timetable would be welcome. Secondsightblog.com awaits your comments.