Chinese medical device company Guangzhou Wondfo Biotech Co Ltd said in an official statement on Tuesday that its SARS-CoV-2 antibody testing kits exported overseas met the quality requirements of China's National Medical Products Administration and countries that they were exported to, and vowed to proactively provide product training to medical staff in each country to ensure the proper use of the test.

The statement came after British media outlets reported that Wondfo's SARS-CoV-2 antibody testing kits exported to the United Kingdom were unqualified and didn't work out very well, and that the testing kits might need a month of trial period before being used. On April 22, the British media outlet amended the article and published a correction note on April 25 clarifying that Wondfo's test was not one of the products reported.

Stressing that the products have undergone strict quality control procedures, Wondfo said that specified guidelines must be followed in terms of the storage, as well as usage of the kits to obtain accurate results.

As stated in the product description, the company's antibody test is for rapid, qualitative detection of the SARS-CoV-2 IgG/IgM antibody in a human whole blood, serum or plasma sample. The test is to be used as an aid in the diagnosis of COVID-19 and cannot be used as the sole basis for diagnosis or treatment decisions, the company said in the statement.

"Judging from the operation rules of the human immune system, there will be a window period of detection after COVID-19 infection, and the window period varies from person to person,"Li Wenmei, deputy director of the point-of-care testing branch of the China Association of Medical Equipment, and also president of Wondfo. 

During the window period, if adopting proper testing methods, such as nucleic acid testing, the coronavirus can be detected. Later on, when the human body begins to produce specific antibodies through the immune response, the sensitivity and detection rate of an antibody testing kit could rise to a high level, he said.

"Therefore, for infected cases who have gone through the window period, using antibody testing as a supplementary testing method effectively raises the detection rate," Li added.

To help overseas medical staff fully understand the intended appropriate use, performance metrics and testing methodology of its detection kits, Wondfo launched online product training through video conferences. Between April 1 and Sunday, it had held 24 video conference trainings, offering guidance to healthcare professionals from Asia, Europe, Latin America and Africa, among others. Wondfo said that between March 9 and Sunday, it had delivered millions of SARS-CoV-2 antibody testing kits to more than 70 countries and regions worldwide.

Zhang Qi, deputy director of the Department of Medical Device Regulation of the National Medical Products Administration, said earlier at a news conference that the Chinese government will further enhance the quality supervision of the exported medical equipment related to pandemic prevention and control, in a bid to offer assistance in the fight against COVID-19.

Starting Sunday exporters of medical products, including COVID-19 testing kits, medical face masks, medical protective suits, ventilators and infrared thermometers, should be recognized by the China Chamber of Commerce for Import & Export of Medicines & Health Products before these goods go through Customs, according to the Ministry of Commerce.