A study by the Chilean health authorities concludes that the effectiveness of the vaccine from the Chinese pharmaceutical company Sinovac is 67% to prevent symptomatic cases of COVID-19 and 80% to prevent deaths in people vaccinated with the two required doses.
The effectiveness of the immunizer CoronoVac showed that 14 days after the second dose was administered, hospital admissions were prevented by 85% and admission to intensive care units by 89%, according to the study released to the press on Friday.
The report, presented by the health ministry’s physician and adviser, Rafael Araos, was created from a sample of 10.5 million people, between February 2 and April 1.
The Chilean Ministry of Health study concluded that “in a scenario of high epidemic activity and in susceptible groups (advanced age and with co-morbidity), the vaccine protects against symptomatic infection by SARS-CoV-2, as well as against the most severe forms of disease. the sickness”.
The analysis is released days after China’s disease control agency’s top authority, Gao Fu, admitted that the effectiveness of Chinese coronavirus vaccines “do not have very high rates of protection,” and that the government is considering combining them. It was an unusual official recognition of the weakness of the Chinese immunizers.
Dr. Araos stated in a subsequent press conference that the sample of 10.5 million people included 6.5 million unvaccinated people, 1.5 million on one dose, and 2.5 million who had received both doses at the end of the study. In this last group that completed the immunization process, 54 people died.
Regarding the 67% effectiveness in preventing COVID-19, the physician illustrated the result by noting that in a group of 100 people vaccinated with both doses, 34 will be infected.
Dr. Jeanette Vega, former Undersecretary of Health and WHO advisor, told The Associated Press that according to the study, the Sinovac vaccine “is becoming a very good vaccine because it has two benefits for developing countries at an intermediate level: the first is that it is much cheaper and the second is that vaccination logistics is much simpler ”.
Pfizer and Moderna American vaccines should be stored at temperatures below 70 and 20 degrees Celsius, respectively, while Sinovacs can be kept in regular refrigerators.
Vega added that “because of the type of vaccine it is, it is less likely to cause immune escape from new variants.” He said that according to preliminary studies in some local hospitals and laboratories, “we (in Chile) have a significant circulation of the P1 variant, the Brazilian one,” which is estimated at 50%.
“These figures indicate that at least a percentage of the vaccinees (considered in the study) likely had P1 infection,” he added.
The Chilean study is the first to be conducted in the field to analyze the effectiveness of the Sinovac vaccine. Until now, only the results of clinical trials developed in controlled environments that measure efficacy were known, but not effectiveness, the authorities point out.
Chile is at the forefront of vaccinations in Latin America with 7.6 million people immunized in just over two months, representing 40% of the 19 million population, while 27% have already received the second dose. The government plans to vaccinate 80% of the population.
Chile succeeded very early in purchasing vaccines from several pharmaceutical companies, which allowed it to sign a contract with Sinovac in June 2020 for 60 million doses over three years. The first shipment arrived in late January and has received nearly 13 million doses to date. Another two million of the ten acquired from Pfizer also came in.
Araos specified that 90.1% of the Chilean population was vaccinated with Sinovac and the remaining 9.9% with Pfizer.
Chilean authorities reported the day before that critically ill patients with COVID-19 over the age of 70 show a sustained decline in recent weeks, and that the age group between 60 and 69 shows a downward trend, while those under 59, who have not yet received the second dose of the vaccine, “have shown a sustained increase”.
They attribute the decline to the fact that people over 70 were among the first to be vaccinated, second only to health officials.
Chile registered the highest number of infections in one day at the beginning of the month, with more than 9,100 cases. Although there has been a slight drop in the number of infections in recent days, it is still impossible to know whether the South American country has already reached the maximum of this second wave. Hospitals have occupied 95% of their critical beds for more than a week, mainly by patients with the virus. Chile has so far registered 1.1 million infected and nearly 25,000 deaths.