The virus knows how to trick the immune system

This is exactly the situation that arose during experiments on rodents. Although most of the animals that received the antibodies were protected, three still became ill. This led the team to look deeper and study the virus from the body of these animals.

It was discovered that the cause was single changes in the virus genome. These so-called ‘elusive mutations’ change the part of the virus that the antibody is supposed to bind to, making it virtually invisible to the drug. At the same time, the mutation does not affect other properties of the virus – it remains viable, but no longer recognisable for immune therapy.

To confirm the hypothesis were conducted experiments in laboratory conditions – without the participation of animals. The conclusion was the same: a particular antibody causes the appearance of mutations in the exact point of the virus, where it is attached.

To cope with the problem, the scientists decided to turn to a strategy that has long been used by nature itself. Instead of a single antibody, they proposed to use several at once. This combination makes it almost impossible for the virus to elude all of them at once.

What’s more, the scientists have learnt to ‘tweak’ the antibodies themselves – to change their structure so that they can ‘catch up’ with the virus even as they change. This is reminiscent of the human immune system, where many cells produce differently structured antibodies, covering a wide range of possible threats.

The University of Veterinary Medicine in Hannover, the Hannover Medical School and the Institute of Virology and Immunology in Switzerland were involved in the research. Thanks to international co-operation, the vulnerability of monoclonal antibodies was not only revealed, but also a way to circumvent it.

Monoclonal antibodies are specially designed proteins created in the laboratory that recognise and ‘stick’ to a specific part of the virus. They act precisely and precisely, unlike conventional (polyclonal) antibodies, which the body produces itself and which attack the enemy from different directions. These antibodies help the body to fight the infection more quickly or not to get sick at all.