The first three

A brief overview of the first Russian coronavirus vaccines

Alexey Paevsky, Indicator

Last week and this week, our scientific editor conducted three conversations for the Stopcoronavirus.rf portal with the developers of three Russian coronavirus vaccines approved for human testing: Sputnik V of the Gamalei NITSEM, EpiVacCorona of the Novosibirsk Vector Center and the vaccine of the M.P. Chumakov Center, which does not yet have a name. We decided to publish a brief summary of these conversations: only facts about vaccines, their trials and use.

Satellite V

Unlike the other two broadcasts, the speaker was not a representative of the creators of the vaccine, but one of the organizers of clinical trials, director of the Institute of Translational Medicine and Biotechnology of Sechenov University of the Ministry of Health of Russia Vadim Tarasov.

The Sputnik V vaccine became the first Russian registered coronavirus vaccine. After the completion of phase I/II clinical trials, the vaccine received a temporary registration certificate "with the condition" to conduct the third phase of clinical trials.

So, what is Sputnik V? This is a vector vaccine. What does it mean? There is a vector in the vaccine – in this case, an adenovirus, which normally causes a person to have a mild respiratory illness. But in the case of a vaccine, the virus cannot even cause a cold: the virus genome has been changed. The virus reproduction system has been "cut out" of it, but one gene from the coronavirus genome has been added. Namely– the S-protein gene, the spike of the coronavirus. Thus, the vaccine causes cells to produce the coronavirus antigen and introduces the cells of the immune system – both humoral immunity and cellular – to the antigen without infection. At the same time, like most coronavirus vaccines, Sputnik V involves two injections, in the case of Sputnik, with an interval of 21 days. But, unlike other vaccines, the vector "Satellite V" implies two different injections. Since there is a possibility of blocking the adenovirus with the available antibodies after the transferred adenovirus, the vaccine is first administered on one platform, adenovirus Ad26, and then on another, adenovirus Ad5.

In phase I/II, first two groups received different components of the vaccine, then the third group received the vaccine according to the booster scheme, receiving first one component, and then the other. In this small group (a total of 38 people), the safety and immunogenicity of the vaccine was shown. After that, a massive post-registration clinical trial of the third phase began, in which several tens of thousands of people took part, a quarter of whom receive a placebo. According to the manufacturers, the effectiveness of the vaccine was 92%. Mass vaccination with Sputnik is now beginning. Doctors and teachers were the first to get vaccinated.

The vaccine is available in two types – liquid, which is stored frozen at a temperature of -18 ° C, and powdered (freeze-dried, "Gum-COVID-Vak-Lio"), which can be stored at a temperature of 2-8 ° C.

"EpiVacCorona"

The vaccine of the Novosibirsk center "Vector" is made on a completely different principle. This is the so-called peptide vaccine. Three synthetic peptides, small sections of viral proteins, the so–called epitopes – the sites to which the immune system is tuned - are "mounted" on a carrier protein and fixed on an adjuvant – aluminum hydroxide. According to the creators of the vaccine, so far the registered coronavirus mutations have not affected these epitopes.

Phase I/II trials have shown the immunogenicity and safety of the vaccine. The authors reported that "induction of specific antibodies occurred in 100% of the volunteers."

More recently, post–registration studies of the third phase have begun in five regions – Moscow, the Moscow Region, Tatarstan, Tyumen and Kaliningrad, in which about 5,000 people should take part (according to other reports – 3,000). The tests will last from November 18, 2020 to June 15, 2021.

Vaccine of the Chumakov Center

The vaccine created at the M.P. Chumakov Scientific Center for Research and Development of Immunobiological Drugs is another option for creating artificial immunity, one of the classic ones, the so–called "killed" vaccine.

What does it represent? In this case, to obtain the vaccine, its authors isolated the coronavirus directly from the patient, then propagate it in a special cell culture (there is a Vero cell culture in the Chumakov Center for this, and, fortunately, the coronavirus "agreed" to multiply in them), and then it is "killed" with beta-propiolactone, which inactivates the virus "seals" the RNA inside the virion in just a day (formaldehyde does it in two weeks). Then the inactivator is neutralized by heating to 37 ° C, after which the killed virions are cleaned and checked to see if everyone is "dead", whether the resulting vaccine can infect the virus cells. After checking, the "corpses" of the virus are injected into the body, allowing the immune system to get acquainted with the entire virion and choose for itself which antigens it is "more convenient" for it to form antibodies.

According to the vaccine developers, preclinical tests on various animals have shown an immune response that lasts at least four months. Phase I/II human trials are currently underway, which should be completed in February, after which decisions will be made on the temporary registration of the vaccine and the start of post-registration trials.

Portal "Eternal youth" http://vechnayamolodost.ru