TASS, July 9. Scientists have summed up the interim results of the third phase of clinical trials of the Chinese coronavirus vaccine CoronaVac, which took place last fall and winter in Turkey. They indicated that the drug prevents 83.5% of coronavirus infections, the researchers write in an article published in the Lancet.
“Our clinical trials provide further evidence of the safety and efficacy of inactivated vaccines. One of the advantages of CoronaVac is that it does not need to be frozen, which makes it easier to transport and distribute. This is especially important when you consider that not all countries have access to low-temperature systems. storage “, – said Professor of the University of Hacettepe in Ankara (Turkey) Murat Akova, whose words are quoted by the press service of the magazine.
The CoronaVac vaccine, developed by the Chinese pharmaceutical company Sinovac, is a weakened version of SARS-CoV-2, whose particles biologists from China have learned to produce in large quantities. She successfully passed the first two phases of clinical trials in the spring and summer of last year, after which the vaccine began to be applied in practice simultaneously with the third phase of its tests.
The first results of these trials, carried out in Brazil, Chile and South Africa, indicated that the vaccine had a relatively high efficacy, about 55-60%, but that it was far behind its adenovirus and RNA competitors. Subsequently, new observational results emerged, indicating a significantly higher efficiency of CoronaVac, approaching the 70-90% mark.
Results of the third phase of trials
Professor Akova and his colleagues have received new evidence that the CoronaVac vaccine is significantly more effective than scientists and ordinary people initially assumed. They received similar information as part of the third phase of clinical trials, which were conducted in Turkey between September 2020 and January 2021.
This experiment involved over 10 thousand volunteers aged 18 to 59 years, two-thirds of whom received two injections of CoronaVac, and the remaining 33% received a placebo. Over the next four months of observation, nine vaccine recipients and 32 participants who received a placebo became infected with the coronavirus. This indicates that the effectiveness of the vaccine is 83.5%.
Testing for antibodies to SARS-CoV-2 showed similar results – they were found in 89% of vaccine recipients, while among the control group, antibodies were present in only 4.4% of volunteers. In addition, scientists have documented relatively few minor side effects such as fatigue, headache, or burning at the injection site. Turkish doctors did not find any serious consequences, which confirmed the high level of safety of CoronaVac.
At the same time, scientists admit that the data they have collected does not include information about how high the effectiveness of the Chinese vaccine against new variations of the coronavirus, including the delta strain, is. As the researchers hope, this information will be obtained in the near future during the follow-up observations of the health of test participants.
See also: All about the coronavirus: a selection of relevant materials
