SHARES in Omega Diagnostics have risen sharply after it confirmed it has redesigned the manufacturing of its much anticipated portable HIV test to provide more consistent quality.

The AIM-listed company decided to take all the manufacturing back in-house to its headquarters in Alva, Clackmannanshire, after results from the Visitect CD4 test were found to vary during initial field trial.

Omega said it has now re-engineered a scalable manufacturing process which is believes will mean all the products it makes meet the correct standard. Three pilot batches have already been produced and given similar results.

That sent shares up 1.75p, or 8.1 per cent, to 21.5p by 2pm.

Kieron Harbinson, finance director, said doing everything in Scotland meant the company was able to control the whole process.

He said: "That has allowed us to effectively deconstruct and reconstruct and fully characterise all of the components of the test. The investigation phase was always about making sure we could build and assemble devices which removed the previously reported variability.

"The completion of the investigation phase means we now have manufacturing processes which we believe are the correct ones and can make a product which is robust and we can consistently make it so it performs and meet design specification."

The business said the protocol it is using is "eminently scalable" so that it could quickly move to be producing millions of the kits.

Mr Harbinson said: "The next phase is this process of verification and validation which proves the selected manufacturing processes can now deliver larger volumes on this consistent basis."

Chief executive Andrew Shepherd confirmed Omega would be running field trials in India and Kenya again as that is where the variable quality of the test first came to light.

He said: "We do have quite a few other people who have come forward in the interim and are looking to evaluate the product as soon as possible. We can very quickly roll out to other evaluation sites in different countries and other [non-governmental organisation] partners after that."

Mr Harbinson said the company was reluctant to put a timescale on when CD4 would be available commercially.

He pointed out the need for internal validation and verification processes which would be followed by the field tests.

Those are likely to take place in the current calendar year although Omega would still have to complete a further regulatory process before launching the test more widely.

Mr Harbinson said: "Completing the validation and verification and having successful field evaluation will put us into a very strong position from a commercialisation prospect."

The CD4 test for HIV provides a quick method of finding out if a person's white-blood-cell counts have fallen to levels where retroviral drug treatment is needed and is expected to be of particular use in developing nations.

Meanwhile in its allergy testing programme Omega said it now has 32 allergens that show equivalent performance to the market leading product.

Of those the company has commercial quantities for 27 and those will be used in tests at sites in Spain and Italy during the summer.

Udine University Hospital Laboratory, in north east Italy, has previously completed a preliminary field study comparing eight allergens on the Allersys system with the market leading ThermoFisher ImmunoCap and found the two were comparable.

The results of that study are being presented at the annual meeting of the European Academy of Allergy and Clinical Immunology in Barcelona, which starts on Saturday.