Smart virus

Smadav can clean some virus that already infected your PC and also fix the registry change made by the virus. Many tools included in Smadav Pro to fight for virus cleaning. Process Manager, to manage processes and programs run in your PC. System editor, to change some system options that usually changed by virus. Win-Force, to force open some system management programs in Windows. Smadav Pro will not show offer to upgrade to pro version on every startup. Prof Teo Yik Ying, professor and dean of the Saw Swee Hock School of Public Health at the National University of Singapore NUS , said that while there have been encouraging signs that the circuit breaker period has been effective so far, the number of new cases has not fallen as quickly as expected.

The three-day average number of new community cases affecting those who live outside of dormitories has fallen from 48 at the start of the circuit breaker period on April 7 to around 25 over the past three days, he said. This points to "leakages" in the community, whether these involve people who venture out without taking the necessary precautions or essential staff who may have to go to work, Prof Teo added.

The experts also noted that people will need to be prepared for changes in policies as new information about the coronavirus is uncovered by scientists around the world.

At the start of the outbreak, for example, only those who were unwell were asked to wear a mask. Prof Teo said knowledge about the transmission of the Sars-CoV-2 virus, which causes Covid, has changed over the months.

Preliminary research in January found that it was unlikely that those without symptoms could be spreading the virus, he said. Now, there is evidence that asymptomatic infections were possible. And as countries start to learn more, our policies need to change accordingly. Policies should also be evaluated in the larger social context, such as the stage of the outbreak in society, and with considerations about the psychological effects of an action. Prof Leo said the effectiveness of masks in preventing respiratory diseases, not just Covid but even with influenza, has constantly been debated.

This goes beyond just putting on a mask, but also about etiquette: "Even in normal circumstances, if people do develop respiratory symptoms, it's always good to put on a mask for personal and societal protection. There was also discussion about the two main types of tests being used around the world to determine if a person has been infected. A virology test detects the presence of viral genetic material in a patient via a process known as polymerase chain reaction.

A serology test, however, tests for antibodies in the blood of people who have previously been infected, said Prof Teo. While serology tests are useful to find out how many people in the population have already been exposed and infected with the virus, they are not without flaws, he said.

The current evidence does not yet support the notion that those with antibodies are immune to subsequent infections, he added. There have been reports that South Korea was seeing a growing number of recovered Covid patients who relapse.

But Prof Leo said the scientific evidence is not robust enough to determine that those who have recovered from Covid could be re-infected. There are multiple possibilities why patients who have recovered test positive for the presence of the virus. One, the ability to pick up the presence of a virus may last for a long time for many patients with respiratory disease infections. After the SARS epidemic, the vaccine that had gone the furthest completed a phase I clinical safety review but then could not be tested further.

Since the number of new confirmed coronavirus cases in China has dropped significantly, it is impossible to evaluate the efficacy of a vaccine in China without a major recurrence of the epidemic. The final protective verification of a vaccine may need to be carried out in highly endemic areas abroad, as with the Ebola vaccine. Caixin: We talked about virus mutation after it jumps to another species. Will it continue changing after infecting humans? Shao: After jumping to humans, viruses could change to either become stronger or weaker.

Those that turn stronger will gradually disappear by natural forces or human efforts. People become unaware or ignore them so they can continue spreading. They transmit among different species and adapt quickly to different hosts. Based on hundreds of publicly available sequences of the new coronavirus, including those collected in Wuhan in the early days of the outbreak and others from different countries, only a dozen of its 30, nucleotide bases changed.

The differences of fatality rates in different regions are mainly due to local medical resources, responsive measures and individual conditions. Caixin: There are many debates about research on the virus. Some researchers want to trace the origin of the virus with genetic analysis while others say the virus has mutated into two strains.

Shao: There are two methods to trace an epidemic — epidemiological investigation and gene sequence analysis. The first method is to track the earliest patients, but it is very difficult due to the long transmission chain and lack of accurate information. But gene sequences do not lie, and it is the most accurate evidence to show evolutionary relationship. If the virus in one person has a similar gene structure with one in another person, the viruses must be from the same root.

Talking about the research on two strains of the novel coronavirus, it is clear that the two strains have only several different nucleotide bases, which is negligible. There are conspiracy theories saying the novel coronavirus was made in a lab. Will gene sequences tell us the truth? Shao: Based on currently available gene sequences of the virus, there is no evidence of human intervention.

We can see it by looking. Of course, people can intentionally erase the trace, but it means massive work. It is possible to create a virus without any visible evidence of human intervention. But it will take a huge amount of tests to prove it is viable and pathogenic. A natural virus from a patient is clearly viable and pathogenic, but it will take massive animal and human testing to know whether a lab-produced virus is viable.

When the workload reaches a certain extent, it becomes a mission impossible. Shao: There is no doubt that China strengthened its disease control system and emergency response capacity after the SARS outbreak. It has done well to contain previous outbreaks of avian influenza such as H7N9 and H5N1. In some cases, the efforts were made with little publicity to avoid public panic. Although avian influenza can cause severe pneumonia, human-to-human transmission has been reported very rarely.

And that is what local disease control departments thought would be enough for controlling Covid at the beginning. In Wuhan, officials closed the seafood market, where the outbreak was believed to emerge, and thought they could get the disease under control. But they ignored the need to report the disease and downplayed the severity of human-to-human transmission, leading to painful results for the public. Under the rules, the cases should be submitted to the system whenever there are more than three unknown pneumonia cases.

The system is in place with a network covering more than 70, reporting points across the country, and doctors can do it with a simple click. The idea of the direct reporting system is to reduce administrative intervention and save time in the face of an epidemic. But after 15 years of operation of this costly system, all the efforts unbelievably turned out to be in vain, and hierarchical review and administrative intervention were back in place.

Why were there such actions, which violate the Law on the Prevention and Control of Infectious Diseases, could happen in government and law enforcement departments? And why did the National Health Commission and its experts fail to collect important information in a timely way? Whether we can find true and adequate answers to these questions will be important to future work.

Shao: First, we must understand that the technical nature of the work at CDCs. They use scientific methods to carry out surveillance of infectious diseases, assess risks and send timely alerts. They also carry out intervention based on the nature of the epidemic and set up national standards and guidance to deal with diseases.

The Covid outbreak proves the problems and the urgent need for CDC reforms. There are about 20, people working in the American CDC system, compared with only 2, in China, and they cover almost four times the population of the U. The U. CDC has more than people focusing on research, warning, intervention, public education and emergency response related to flu virus, but the team in China is only There should be dedicated teams to track and conduct long-term studies of seasonal flu, novel influenza and respiratory infections.

They need to carry out massive surveillance, sample collection, testing and analysis to study the virus and response measures. China has identified 36 infectious diseases in the Law on the Prevention and Control of Infectious Diseases, but fewer than half of the diseases are under study by dedicated teams. Although the China CDC has strived to hire high-end talent over the past 10 years, it has difficulties retaining them.

There are usually two paths of disease control system reforms. The first is to make it an administrative organ, and the second is to maintain its status but reinforce its function.

CDC is not a management department. Instead, it engages in the concrete job of preventing and controlling diseases. Making the CDC an administrative department may turn technicians into bureaucrats and lead to an even worse result.

The political system and the whole society should cultivate an environment with respect for science and scientists and let technology have a say. Allowing professionals to do things they are good at, the society will run in a better way. Opinions from technical departments should be an important reference for political decision-making, but technical departments should be allowed to remain independent.

Scientific education of the general public is also important for people to make the right judgment. Shao: Institution-building should be enhanced in the disease control system. In the U. The frequent outbreak of zoonotic diseases those transmitted from animals reminds us of the importance of cross-department cooperation.

On the other hand, the national CDC should not only function in Beijing. In countries like the U.