By: REN Ziyi DavidEdited by: WANG Yichun

Both BioNTech and CoronaVac vaccines reduce the risk of infection from the British and South African variants, though the effectiveness is lower, the Hospital Authority said at a press conference today. The efficacy of BioNTech against the British variant is 89.5% while the one against the South African counterpart is 75%, according to Qatar research. CoronaVac, the Chinese-made vaccine also known as Sinovac, which is around 50% effective according to some tests in Brazil, is only 30% effective against the South African virus variant, said Dr Owen Tsang, the Medical Director of the Hospital Authority Infectious Disease Centre. “Sinovac is just so-so in dealing with the South African virus,”  he said, “but getting vaccinated would definitely be protective.” No data is currently available to show the effectiveness of the vaccines against the Indian variant, which has been discovered in more than 17 countries. “Since the variant is relatively new, many clinical manifestations are not clear,” said Dr Tsang. Dr Tsang also said that natural infection could prevent reinfection at 84%.  Symptoms after reinfection, such as feeling tired and breathing with difficulties, are much lighter compared to the first infection. “Those who have been infected only need one shot for further protection,” he said, “and I believe even one shot could protect most people from being infected.” Hong Kong had the first reinfection case in the world in August. The 33-year-old man was infected early in March and tested positive again after staying in Spain for a week. He recovered in five days.

A new method of delivering Chinese medicinal herbs may be useful in the treatment of a particularly aggressive form of breast cancer, researchers at Hong Kong Baptist University and Cornell University have found. Speaking at a press conference on Tuesday, Dr Kwan Hiu-yee, an assistant professor at  Hong Kong Baptist University’s School of Chinese Medicine explained that gambogic acid, which is derived from a local plant is useful in cancer treatment. But it does not dissolve easily in water.  That limits its use in traditional Chinese medicine since most herbal treatments have to be boiled. Researchers tested two groups of mice with triple negative breast cancer cells. One using nanocarriers to deliver gambogic acid and the other without. The result showed that the weight of the tumor among the first group of mice decreased 67.6% on average after 17 days. The concentration of the drug was also three times higher two hours after delivery using nanocarriers. The new therapy also has reduced side-effects on the liver.  “Treatment of triple negative breast cancer has not been effective and is very expensive, said Prof Bian Zhaoxiang, professor in Chinese Medicine Clinical Studies at  Hong Kong Baptist University. The nanocarriers may offer hope in effective treatment in future.  But the cost for one dose of targeted therapy is between $2000 and $5000 US dollars. “The triple negative breast cancer takes up 25% among all the breast cancer,” said Prof Bian. “This new method for drug delivery with reduced side effects may help more people in future, “ Prof Bian added.