CoronaVac has passed the early stages of clinical testing

“The CoronaVac vaccine caused a good immune response about a month after it was administered twice, two weeks apart. This allows it to be used to protect the population in the event of an epidemic. In the future, to improve vaccination effectiveness, the interval between injections can be increased to one month, but the effectiveness of this has yet to be evaluated, “said Zhu Fengcai, professor at the Center for Control and disease prevention of Zhejiang Province in Hangzhou, China, whose words press service magazine.

Over the past year, scientists from Russia, the United States, Australia, China and numerous other countries have announced the start of trials of various types of vaccines against a new type of coronavirus, some of which are being tested in animal experiments and others. on volunteers. The final stages of clinical trials for some vaccines are expected to conclude early next year.

Among these drugs are the classic inactivated and recombinant vaccines and vaccinations based on new and almost unexplored technologies that allow to introduce fragments of foreign RNA into human cells and forcing them to produce a large amount of viral proteins.

On August 11, Russia was the first in the world to register a coronavirus vaccine based on two strains of adenovirus, called Sputnik V. The drug was developed by the Center. Gamaleya and underwent clinical trials in June July. It is based on the already known platform on which numerous vaccines have been created. On August 15, the Ministry of Health announced the start of production of the drug. On 25 August, the third phase, following registration, of clinical trials on the Russian vaccine began.

CoronaVac, developed by the Chinese pharmaceutical company Sinovac, is a weakened version of SARS-CoV-2, whose biological particles from China have learned to produce in large quantities. Scientists tested this vaccine for safety in preclinical tests on mice and monkeys. Clinical trials on volunteers, according to Professor Zhu Fengcai and his colleagues, began in mid-April and early May of this year. These experiments, in which scientists simultaneously assessed the vaccine’s safety and efficacy, involved over 700 healthy volunteers who agreed to receive two doses of the vaccine two to four weeks apart.

These experiments demonstrated that injections of the attenuated virus were well tolerated by the volunteers and elicited an immune response in most of them 28 days after the first dose of the vaccine, at both high and low doses. In all cases, except for one episode of developing allergy, the scientists recorded only minor side effects, such as a headache or a burning sensation where the vaccine was injected into the volunteers’ bodies.

As further observations showed, the introduction of the vaccine led to the appearance of antibodies to the coronavirus in the vast majority of volunteers, but there were significantly more of them among the experiment participants who received the second dose of the vaccine with a interval of 28 days.

In both cases, the concentration of antibodies was slightly lower than their concentration in the body of those who had been ill. Professor Zhu Fengcai and his colleagues note that these molecules were sufficient to completely neutralize the virus and protect the volunteers from being infected with COVID-19.

This will allow this vaccine to be used in the future when unexpected outbreaks of COVID-19 appear and prevent its subsequent spread around the planet.