This morning (10th), a reporter from the head office interviewed Liang Wannian, head of the expert group of the National Health Commission's New Coronary Pneumonia Epidemic Response Leading Group. Respond to issues such as the difficulty of the virus and the new challenges brought by asymptomatic infections to "dynamic clearing".

 How do you view the number of asymptomatic infections in the Shanghai epidemic?

What new challenges and uncertainties will asymptomatic bring to "dynamic clearing"?

 Liang Wannian, head of the expert group of the National Health Commission's New Coronary Pneumonia Epidemic Response Leading Group, Executive Vice Dean and Professor of the Vanke School of Public Health and Health, Tsinghua University, said:

The Omicron variant has a very important related feature: asymptomatic infection The proportion of those affected is relatively high, and the current round of the epidemic in Shanghai has fully demonstrated this feature.

There are many reasons for the high proportion, such as widespread vaccination, even after infection, the formation of effective resistance.

After being infected with the virus, the patient's condition can be milder or even asymptomatic, which is an effect of epidemic prevention.

  We've been fighting the Omicron variant for a while now, and it's coming too fast.

There is a deep feeling that we can't beat it with the way we played against Delta, Alpha, and Beta variants in the past.

It is necessary to run at a faster speed, and this faster speed means that the measures must be implemented quickly, and the speed must be fast.

  Second, the Omicron variant is very spreadable.

Once there, if there is no intervention, one (infected person) will pass 9.5 people, which is also recognized internationally.

If the measures are not resolute and not thorough, it (communication power) will not be less than 1.

  Therefore, the measures we are taking now, whether it is nucleic acid testing or global static management, is to do everything possible to reduce the transmission value to below 1.

Once the pressure is below 1, it means that one person will not be able to spread to one person, and the inflection point will appear, and it will not continue to spread.

  Moreover, it spreads at short intergenerational intervals.

At the earliest, when the original strain appeared, we talked about the transmission of several generations, from the first generation, the second generation to the third generation, and the interval between each generation was nearly 7 days.

Now this virus is a generation in about three days, and there is an exponential growth between each generation.

It is conceivable that it has caused great difficulty in prevention and control.

Because infected people don't necessarily show symptoms right away.

Because the time is too fast, when symptoms are found, it may have been passed down to people, two or even three generations.

  If the intergenerational interval is long, there is still time to manage and control it when it is discovered; if it is a little slower, it is probably not a problem of one generation and two generations, so this is the most difficult thing for us to prevent and control.

  Doing nucleic acid and antigen over and over again is to remove it (virus), expand the scope as much as possible, find out all possible sources of infection, and then manage it so that it can be cut off.

With just a little bit of leakage, it quickly grows exponentially again.

Therefore, this is the most important difficulty in current prevention and control.

Shanghai is a mega city with a very high population density. If you don't pay attention, it will reappear at a certain point.

  (Headquarters reporter Wei Ran Yang Jing Wang Zhaoshun)