Wu Zunyou said: At present, because its mutation is also a mutation of a branch within the subtype of the Omicron family, the risk of causing a new round of transmission immediately should not be too great.
Here, in fact, everyone is worried about the problem of secondary infection, after all, whose body is not iron!
However, secondary infection is divided into several different situations:
That is, the strain popular in my hometown is the same strain as the one that is popular in my own city.
Generally speaking, after infection with the new crown virus, the antibodies in the body can be maintained for more than 3-6 months to prevent you from being infected twice.
But the premise here is for the same strain, for example, after the family is infected one after another, the probability of infection is the same strain, then the person who recovers first will not be re-infected because of the virus excreted by the person who was infected later.
The same applies to the difference between your hometown and your own city.
For example, from the sequencing results of the new coronavirus submitted nationwide, for example, the virus in Beijing and Fujian may be closely related to the BF.7 strain in Inner Mongolia, then it can also be understood that the strains in Beijing, Fujian, and Inner Mongolia and other provinces are the same type of strain, so that for people after infection, secondary infection is unlikely to occur in the short term.
Then let's look at the second case, not the same strain.
For example, I was infected with BF.7 in the north, and then went to the city with a high incidence of BA.5.2 in the south. Will that be a secondary infection?
From the current laboratory research and clinical performance, these two strains still have a certain cross-protection ability of antibodies.
For example, the above picture is a neutralizing antibody experiment done by Cao Yunlong's team, using 3 injections of Sinovac vaccine plus BA.5 neutralizing antibodies in the serum of recovered patients with breakthrough infection to neutralize different strains.
It can be seen that for the BF.7 strain, the neutralization ability is still in a relatively high position.
Therefore, it is judged that people infected with the BA.5 strain will generally not be reinfected with BF.7 in the short term.
Conversely, it is also a similar situation, after 3 shots of Sinovac vaccine and then breakthrough infection with BF.7, the neutralization ability of antibodies in the body for BA.5 strains is still very high, even higher than that of BF.7 strains.
Therefore, simple domestic inter-provincial activities, at least during the spring group, do not have to worry about being infected twice.
The third situation is to travel abroad.
Because there are now many variants in the world, especially the XBB.1.5 strain in the United States, which is currently the main epidemic strain.
It can be seen that xbb.1.5 has had a rapid growth in the United States in a very short period of time. The current speculation is that XBB.1.5 may have a very strong escape ability, and it can also be seen from the neutralization antibody experiment of Cao Yunlong's team above, the same antibody, when neutralizing XBB.1.5, the neutralization ability is very poor.
That is to say, when you travel abroad, for example, the destination has a breakthrough infection such as XBB.1.5 or BQ.1.1.10 that is very strong, and there is a very low strain of antibody cross-immunity in your body, it is possible to be re-infected.
However, there is also a situation that has to be considered, that is, the reverse import of foreign returnees or inbound tourists in the next period.
The fastest XBB to enter the country is expected to be after the release on January 8, many overseas people who have not returned to China for several years, as well as the first batch of inbound tourists who may encounter, will bring us back special strains from all over the world.
The next step is to gradually increase the proportion of infection, and because this meeting should be the peak period of the Spring Festival in China, XBB.1.5 should be mixed in the peak period of the Spring Festival and gradually spread throughout the country.
But the peak of the Spring Festival also means that a large number of people are infected or recovering from BA.5.2 and BF.7, so this time point is critical, and the time to test the breakthrough infection ability of XBB.1.5 has come.
If XBB.1.5 can break through the antibody defense line that has just been infected with BF.7 and induce a second round of infection, the first wave of the epidemic and the second wave of the epidemic will be superimposed continuously during or after the Spring Festival.
If it can't break through so quickly, it should be in March and May, that is, after the first wave of absolute peaks, is the growth space of XBB.1.5, as for how high it will be, there is no international reference at all.
Assuming that XBB.1.5 can quickly break through our existing immune defense line, it may be possible to encounter XBB.1.5 during the Spring Festival and may also be re-infected.