The use of serology to demonstrate circulating antibodies to FHV-1 has been shown to have a positive predictive value for indicating protection from this disease.

Purified polysaccharide vaccines activate immune system to produce protective and circulating antibodies against the disease.

The researchers took blood samples to measure circulating antibodies before the inoculation, and then after one month and after four months.

Sadly, with syphilis, the measurable increases in the blood levels of circulating antibodies do not reflect any useful level of protection against repeated infection.

Other reports also suggest that in this disease there are circulating antibodies against antigens common to biliary and colonic epithelia.

This may relate to differences in the level of circulating natural antibodies between the two species.

There have been conflicting reports of raised levels of neutralising, circulating antibodies to adenovirus 12 in coeliac disease patients.

On the other hand, consumption of circulating antibodies cannot be ruled out in the seronegative instances.

The B lymphocytes maintain immunity by enabling the body to produce and preserve circulating antibodies.

In contrast circulating antibodies provide long-term protection without toxic side effects.