1 . The development of the mRNA vaccine (疫苗) — a breakthrough in its field, instructing cells (细胞) to produce their own protection without the risk of giving someone the virus — was fast and effective, made possible through rapid genome sequencing (基因组测序).

So how does it work? Once mRNA is injected (注射), the vaccine attaches to a cell, instructing it to produce a harmless copy of the spike protein — the significant marker of the coronavirus, which allows COVID-19 to inject itself into human cells — causing an immune response. Because mRNA does not enter the cell nucleus (细胞核), it does not change human DNA.

Different from the time it takes to produce traditional vaccines，which are time-wasting and expensive, mRNA can be produced almost instantly.

It’s been a “game changer,” says Tom Kenyon, a former director of global health at the U. S. Centers for Disease Control and Prevention. “These are vaccines that give very strong immunity, which we never had in previous attempts.” Besides, its potential to treat cancer, which it can do by causing the immune system to target cancer cells, is especially exciting. Most traditional immune treatment for cancer uses “passive immunity,” where a drug doesn’t always last long. But active immunity, achieved with mRNA, means the body can remember how to create the response on its own. “That’s what gives everybody in the public health community hope,” Kenyon says.

The biggest drawback is production ability. Many parts of the world would need help setting up the ability to produce these vaccines. “The mRNA story is by far the greatest story of this pandemic (流行病), and it’s an amazing scientific achievement, but we haven’t translated that yet into programmatic results, and that’s what matters,” Kenyon said.

There is strong evidence     1     vaccination (接种疫苗) is the best defence against deadly and weakening infections, such as measles.

Vaccines protect billions of people around the world. They have completely got rid of one disease-smallpox-and are bringing the world close to     2     (remove) others, such as polio. But some other diseases, such as measles, are making a resurgence (死灰复燃) and experts say people’s avoiding vaccines, fueled by fear and misinformation,     3     (be) one of the main causes. Vaccine hesitancy (犹豫), or mistrust of vaccines, has the potential, at least, in some places,     4    (block) the very real progress the world     5    (make) in controlling vaccine-preventable diseases. What makes people skeptical? There are likely to be many factors     6     (involve). Some of it may be complacency (侥幸)     7     a disease has become less common, then the need to get immunized (免疫) may feel less pressing when weighing the benefits     8     any possible risk. Besides, the internet means beliefs and concerns about vaccines can be shared in an instant, spreading information     9     experts say isn’t necessarily based on fact.

One of the most important ways to remove doubt about vaccines is to have health workers really well trained and able to recommend vaccinations based on     10     (science) truth.

Nowadays, face masks are being worn all over the world, but China is one of first countries to realize the     1    (important) of the wearing of face masks. In fact, it is also a result of traditional cultural factors in China.

These include the beliefs     2    (root) in traditional Chinese medicine, of     3     qi is a hugely important concept. The Chinese character for qi is related to air, breathing, and energy. People believe that     4     one is low on qi, they are more likely to fall ill. Thus,     5    (maintain) a supply of clean air in one's lungs is important. Because face masks can filter out     6    (poison) matter in the air, people tend to consider them a useful tool for disease     7    (prevent).

Some experts argue that effectiveness of face masks in preventing disease is great. According to Dr. Deng Xiaofan, a medical advisor, face masks can actually prevent the spread of     8    (virus) on condition that they are worm correctly. Other experts have pointed out that healthy people do not need to be     9    (constant) wearing them when not in public. When it comes to preventing COVID-19, authorities advise correct face masks wearing and frequent hand washing     10     effective ways of controlling the spread of diseases.