If I use the hand foam continuously will it reduce my body’s natural resistance to germs and will that mean if I get a cold or virus, it will be worse than usual?
The hand foam doesn’t have any effect on your immune system, so your body’s natural resistance to germs isn’t affected. If you do get a cold after using the products, that’s because each cold is caused by a different virus strain and you don’t ever get immunity from all colds. The severity of the cold or illness will depend entirely on the strain of virus that has caused it.