A study published by the Chilean health authorities concludes that the vaccine’s effectiveness with 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 CoronoVac immunizer showed that, 14 days after the application of the second dose, it prevented hospitalizations by 85% and admission to intensive care units by 89%, according to the study published on Friday.
The report, presented by the doctor and adviser of the Ministry of Health, Rafael Araos, was made on a sample of 10.5 million people, between February 2 and April 1.
The study by the Chilean Ministry of Health concluded that in a scenario of high epidemic activity and susceptible groups (elderly and with comorbidities), the vaccine protects against symptomatic SARS-CoV-2 infection, as well as against the most serious forms of the disease. “.
The analysis comes a few days after China’s top disease control agency, Gao Fu, acknowledged that the effectiveness of Chinese coronavirus vaccines “does not have very high protection rates” and that the government is considering combining them. It was an unusual official admission of the weakness of Chinese immunizers.
Dr. Araos specified in a subsequent press conference that the sample of 10.5 million people included 6.5 million unvaccinated people, 1.5 million with a single dose and 2.5 million who at the end of the study had received both dose. In the last group that completed the immunization process, 54 people died.
Regarding the 67% efficacy in preventing COVID-19, the doctor exemplified the result by mentioning that in a group of 100 people vaccinated with both doses, 34 will be infected.
Dr Jeanette Vega, former Undersecretary of Health and WHO Adviser, told The Associated Press that according to the study, the Sinovac vaccine “becomes a very good vaccine because it has two advantages for intermediate developing countries: the first is that it is much cheaper and the second is that the logistics of vaccination are much simpler ”.
The American vaccines from Pfizer and Moderna must be kept at temperatures below 70 and 20 degrees Celsius, respectively, while Sinovac can be stored in regular refrigerators.
Vega added that “due to the type of vaccine it has, it probably produces less immune escape from the new variants.” He said that, according to preliminary studies conducted in some local hospitals and laboratories, “we have (in Chile) a significant circulation of the P1 variant, the Brazilian one”, which is estimated at 50%.
These figures reflect the fact that at least one percent of those vaccinated (considered in the study) probably had a 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, but not efficacy, were known, authorities say.
Chile leads in vaccinations in Latin America with 7.6 million immunized in just over two months, representing 40% of its 19 million inhabitants, while 27% have already received the second dose. The government intends to immunize 80% of its population.
Chile managed to purchase vaccines from various pharmaceutical companies very early, which allowed it to sign a contract with Sinovac in June 2020 for 60 million doses in three years. The first shipment arrived at the end of January and has so far received almost 13 million doses. Another two million of the ten purchased from Pfizer have arrived.
Araos said 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 patients with severe COVID-19 over the age of 70 have experienced a steady decline in recent weeks and that the 60-69 age group reflects a downward trend, while those under the age of 59, who have not yet received a second dose of vaccine, “showed sustained growth”.
They attribute the decline to the fact that those over 70 were among the first to be vaccinated, second only to health officials.
Chile recorded the highest number of infected in a day at the beginning of the month, with over 9,100 cases. Although there has been a slight reduction in the number of infected in recent days, it is still impossible to know whether the South American country has already reached the maximum of this second wave. For more than a week, hospitals have occupied 95% of critical beds, mainly patients with the virus. Chile has so far recorded 1.1 million infected and nearly 25,000 deaths.