① If you've ever seen alpacas (羊驼), you might just think they're fuzzy and cute. Now, it looks like this animal might be able to help scientists find a vaceine (疫苗) for COVID-19.
②In Australia, scientists are examining an unusual immunity (免疫) from alpacas that create two types of antibodies (抗体). Actually, the alpaca's unusual immune response had already been used in research for other viruses, such as HIV, around the world. Now the scientists have found that when alpacas are infected（感染) with COVID-19, their bodies react in a special way.
③"Alpacas and animals like them actually create two different types of antibodies. One is similar to the type humans make, but they also create things called nanobodies (纳米抗体)," said Michael James, a researcher who takes part in the study. The alpacas produced these nanobodies after researchers put a COVID-l9 viral spike protein (刺突蛋白) into their bodies. It is this protein that helps the virus infect our cells (细胞). The nanobodies, however, could stop infection from happening by blocking the protein.
④"You can think of our cells as a 'lock' and the viral spike protein as a 'key'," James explained. He said the nanobodiesplug upthe "lock" so that the "key"cannot get in.
⑤ Although the results look good so far, it will take some time to produce a vaccine based on the findings. The nanobodies require far more research to make sure they are both effective and safe. Since the nanobodi are newly found, they must be tested very strictly in the laboratory before they can be tried on human, according to James.
