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New Antibody Attacks 99% of HIV Strains (bbc.com)
An anonymous reader quotes a report from BBC: Scientists have engineered an antibody that attacks 99% of HIV strains and can prevent infection in primates. It is built to attack three critical parts of the virus -- making it harder for HIV to resist its effects. The work is a collaboration between the US National Institutes of Health and the pharmaceutical company Sanofi. Our bodies struggle to fight HIV because of the virus' incredible ability to mutate and change its appearance. These varieties of HIV -- or strains -- in a single patient are comparable to those of influenza during a worldwide flu season. So the immune system finds itself in a fight against an insurmountable number of strains of HIV. But after years of infection, a small number of patients develop powerful weapons called "broadly neutralizing antibodies" that attack something fundamental to HIV and can kill large swathes of HIV strains. Researchers have been trying to use broadly neutralizing antibodies as a way to treat HIV, or prevent infection in the first place. The study, published in the journal Science, combines three such antibodies into an even more powerful "tri-specific antibody." The experiments conducted on 24 monkeys showed none of those given the tri-specific antibody developed an infection when they were later injected with the virus. "We're getting 99% coverage, and getting coverage at very low concentrations of the antibody," said Dr Gary Nabel, the chief scientific officer at Sanofi and one of the report authors.
Welcome to core Statistics.
This would have to be a randomized controlled experiment, and the confidence interval being tested would be 99%. What this means in frequentist statistical terms is that if you had 100 test subjects, and out of those you would expect for whatever reason one of those would somehow turn up positive, then you would still be within your 99% confidence interval. More formally stated, the true population mean is somewhere greater than the 2.5th percentile and less than the 99.5th percentile of the the distribution of the values in your samples.
So, because they are working with statistical sampling methods, they never say that they are 100% confident.
I was about to mod this down, but perhaps explaining all the things that are wrong with this is a better way to go.
You are correct in that 100% coverage would be needed to kill off the virus. HIV is notorious for repopulating a system if even as much as a single virion is alive. What is completely off is that 6 SNPs would protect against antibody recognition when there are 3 of them, all broadly neutralizing. The antibodies can very well have overlapping epitopes for different patterns resulting in recognition regardless of any variation, as has already been shown to be the case by TFA. Ignoring the entire purpose of the broadly neutralizing antibodies is necessary for your analysis to seem accurate.
Next, the matters of genomics. If the antibodies recognize any specific phenotype in the viral episome, and that phenotype is conserved, it is quite tricky for the virus to produce an immunity without altering a core protein of itself. Usually, that would not be a problem for a virus such as HIV as there is lots and lots of variation possible within a protein without changing its function, but when dealing with broadly neutralizing antibodies the change must be significant or it will still get caught in a broad recognition. Hence, it is not enough to change a nucleotide or two, that change must result in a significantly different phenotype which means the expressed protein would function differently (or not at all). That is why these antibodies have already been proven to work efficiently.
In short: no, your interpretation does not represent how it works at all.
No. Very few people ("long term non-progressors") create effective antibodies that can successfully control the infection. These new antibodies are actually tweaked and did not emerge from any person. The antibodies are manufactured and shipped for injection, and they must be refrigerated. Assuming they are human-derrived, they will last in the blood for a month. These are likely "monoclonal antibodies," and drugs that use this technique have names that usually end in -MAB. They're quite expensive.