Typically, when we start using a vaccine for any given diseases at a large scale, and on regular intervals, the bacteria or virus causing that diseases evolves to counter this. Same is happening now with the bacteria which causes whooping cough.
Currently, vaccines are used to inject the babies so that they are able to grow immune to the whooping cough early in their age. However, new findings show that the bacteria which causes this disease is changing in response to the vaccine and evolving itself accordingly.
For now, the new bacteria strains which have been found are no more or less harmful than the regular whooping cough bacteria. And the vaccine which is currently prevalent is effective on both of them. But there are certain features of the new strain which may become a cause for concern in the coming days.
For instance, before 2010, the overwhelming number of infections caused by the whooping cough bacteria included a protein called pertactin. In more recent cases, there has been a rapid increase in the number of such infections where the pertactin is no longer produced in the human body by the bacteria. This is an abnormal and evolved behaviour but it is clearly in response to the vaccine.
That’s because the vaccine of whooping cough relies on two or three such molecules which are injected into the human body. These include pertactin and typically, are used to train the body’s immune system that it must identify these foreign elements and develop strong defenses against them. So when the actual disease strikes, body’s immune system is ready to counter it and fight it off.
The problem is that the new strain of bacteria no longer produces pertactin. That hasn’t posed any troubles yet because the other molecules used in the vaccine are still produced by the whooping cough disease, so the vaccine is effective in fighting off the bacteria. But if the bacteria eventually stops producing any of the molecules used in our vaccine, that would render the cure useless. And that is an alarming possibility.
Courtesy: Pop Sci