Chile, with a vaccination rate of over 60%, has locked down its cities again. What lessons can we learn from this for my country's epidemic prevention and control?

The Chilean capital is under lockdown again.

With over 8,000 confirmed cases and over 200 deaths in a single day, Santiago, the capital of Chile, announced another lockdown. The recurrence of the epidemic in Chile has caused panic among many people. As a country ranked in the top five in the world in terms of vaccination rate, more than 60% of the people in the country have received at least one dose of vaccine. Logically, the epidemic should be gradually under control. However, since the end of May, the epidemic in Chile has rebounded significantly, and the number of confirmed cases has increased instead of decreased. So far, the total number of confirmed cases in Chile has exceeded 1.4 million, and the cumulative number of deaths has reached 29,000. So what caused the rebound of the epidemic? Does the rebound of the epidemic in Chile mean that the vaccine has failed?

Chile's epidemic rebounded because of insufficient vaccine effectiveness? So far, Chile's vaccination rate is the highest in South America. Chile has administered 23 million doses of the new crown vaccine, including 17.2 million doses of Sinovac vaccine, 4.6 million doses of Pfizer vaccine, and about 1 million doses of Oxford and CanSino vaccine. Why did the epidemic rebound again with such a large coverage of vaccines? Is it because the vaccine is not effective enough?

Let's first look at the actual effectiveness of the Sinovac vaccine in Chile. From the figure below, we can see that the actual effectiveness of the Sinovac vaccine in Chile is 67%, the effectiveness in preventing hospitalization is about 85%, the effectiveness in preventing ICU is about 89%, and the effectiveness in preventing death is about 80%. This is basically consistent with the previous Phase III clinical trial data of the Sinovac vaccine in Chile.

In other words, after taking two doses of Sinovac vaccine, 33% of people are still likely to be infected. We have repeatedly emphasized that the reason why we call on everyone to get vaccinated against the new coronavirus is not simply to prevent infection, but more importantly to prevent severe illness. If they are not vaccinated, Chile may now have more than 20,000 new deaths and more than 500 deaths.

Premature lifting of the lockdown is an important factor in the rebound of the epidemic. June last year was the peak of the first wave of the epidemic in Chile. Through the lockdown and epidemic prevention and control, the epidemic in Chile was gradually brought under control. In addition, the vaccine began to be widely vaccinated, and Chile relaxed its vigilance. Perhaps due to economic pressure, Chile gradually relaxed population mobility in January this year, which brought about the acceleration of the spread of the virus, especially with the emergence of the new coronavirus variant P.1 (Gamma), the virus's ability to spread has increased. In addition, Chile is now in winter, and the climate environment is more conducive to the spread of the virus, so there has been a second rebound in the epidemic in Chile.

Why are young people mostly affected by this epidemic rebound?

If you carefully analyze the infection data released by Chile, you will find that the second wave of the epidemic in Chile has changed the age group compared with last year. This epidemic is more "favored" by young people, especially there are obvious differences between the group under 59 years old and the group over 70 years old.

Why is there a difference in age groups? Many people say that the variant of the new coronavirus, P.1 (Gamma), is more contagious to young people. Perhaps this is the reason, but many people have overlooked an important reason. Due to the shortage of vaccines in the early stage of vaccination, Chile gave priority to the elderly, so many people over 70 years old have been vaccinated with the new coronavirus vaccine. The number of infected people over 70 years old in this rebound is relatively low, which also reflects from the side that the new coronavirus vaccine plays a vital role in the epidemic.

What lessons can the Chilean epidemic teach us about epidemic prevention and control in my country? Get fully vaccinated against COVID-19 as soon as possible

Through the real data of Chile's second wave of the epidemic, it can be found that the new crown vaccine has good effects in preventing infection, preventing hospitalization, avoiding severe illness, and preventing death. It should be pointed out here that the antibody level of the Sinovac vaccine can only reach a higher level after two injections, so strict protection should still be taken after one injection or just after two injections.

Appropriate social control is still necessary

The rebound of the epidemic in Chile is closely related to the premature relaxation of population mobility. Before herd immunity is achieved, it is necessary to isolate the infected people in a timely manner. Whether it is the full nucleic acid testing in Guangzhou or the strict restrictions on entry and exit in some areas, it plays a very important role in controlling the epidemic.

I also hope that everyone will continue to do a good job of personal protection and never take the epidemic lightly at any time!