“Sign me up!”
That was my first, emphatic reaction to word that University of Massachusetts Medical School researchers are making progress toward a shot that we here in Lyme disease territory could get every spring for months-long protection through high tick season. It would use monoclonal antibodies — medical cruise missiles that can hit the narrowest of targets.
Sadly, the research, though promising, is still only in mice, and it will be years before such a shot could possibly be available in humans. But for those of us eagerly awaiting better protection against Lyme disease — not to mention those of us frustrated by this: Why your dog can get vaccinated against Lyme disease and you can’t — it’s heartening news nonetheless.
I asked for details from UMass Medical School professor Mark Klempner, a longtime Lyme disease researcher and executive vice chancellor of MassBiologics, a non-profit, UMass-affiliated maker of vaccines and other public-health-oriented medicines. His colleague, Dr. Yang Wang, just presented their team’s findings to a major conference on infectious disease in San Diego. His summary:
“For the past two-and-a-half years, MassBiologics has been developing a new approach to prevention of Lyme disease, as part of our overall public health efforts to protect the citizens of Massachusetts and beyond for diseases of interest.
We’ve taken a different approach than the vaccine approach, and what we’ve developed is a human monoclonal antibody that, when present in the blood of a host, will prevent the transmission of the Lyme disease bacteria from the tick to that host.
When the tick bites you, it then drinks in a little bit of your blood, and contained within that blood is the medicine that kills the bacteria right in the gut of the tick.
I want to emphasize that so far these studies have been done exclusively in animals — so-called preclinical studies — and our future is to move this into clinical studies, which we will hopefully initiate in 2016.
The idea here is based on a couple of precedents. The first is: We know that the previously available [Lyme disease] vaccine worked by inducing many, many different antibodies, only one of which was important in the protection. And similarly, we know that there is a precedent for being able to give a safe and effective monoclonal antibody to young babies in order to prevent them from getting a different infectious disease called Respiratory Syncitial Virus.
So for both precedent and safety reasons, we chose to go after a single monoclonal antibody that would be able to prevent the transmission of Lyme disease during the entire season. The monoclonal antibody idea has additional benefit in that when the vaccine was available, it required three shots over six months to induce immunity, and so you needed to start to take the medicine sometime in the winter in order to be able to protected in the following fall, and there was not a lot of uptake of that.
So here, one of the advantages is that the antibody, if we give it to you, provides you immediate immunity, as it does in a mouse, and it should last for the entire season by engineering the antibody to have a very, very long half life. And then it would be gone at the end of the season, and the next season you would take the medicine again and it should work again for the entire season.
The overall mechanism of the way the antibody works is quite interesting and unique, and it’s really based on the idea that the way you catch Lyme disease is, obviously, by the bite of the tick, and what happens in the tick when it drinks your blood is that there’a a sudden explosion of the organisms in the intestine of the tick, where they begin to multiply very quickly; they change somewhat and then they invade the tick gut and move to the salivary gland, where, during the feeding process they can then be deposited in your skin, where you get that typical bullseye rash, often.
So here the idea is that if you have the circulating antibody going around when the tick bites you, it then drinks in a little bit of your blood and contained within that blood is the medicine that kills the bacteria right in the gut of the tick and thereby prevents transmission.
When we do these studies in mice, that’s exactly what happens. Continue reading