Russian Health Ministry's chief epidemiologist Nikolai Briko: work on universal coronavirus vaccine underway
Nikolai Briko
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The Russian Health Ministry's chief epidemiologist, Public Health Institute Director Nikolai Briko, has given an interview to Interfax in which he speaks about coronavirus mutation and efforts to develop a universal coronavirus vaccine.
Question: Is it possible to say that the Delta variant is a new highly contagious virus?
Answer: Of course not. This is not a new virus. We’re talking about an antigen variation of the SARS-CoV-2 virus and the formation of a new antigen viral variant. This is a natural biological process inherent to all RNA-containing viruses, including SARS-CoV-2, especially when it jumps from an immune organism to a non-immune one, when the mutation speed grows. Yes, of course, global monitoring of the viral variant is needed. It goes in parallel with the flu virus in the system of the Gisaid and Nextrains digital platforms for monitoring the variation of SARS-CoV-2 and the flu virus and the Pango platform for SARS-CoV-2, which monitors new variations and transmission speed, primarily, the virus's virulence and the reproductive number.
Q.: And this means?
A.: The reproductive number, R0, describes, let me put it this way, the virus contagion, which means the number of people that one person can contaminate. For example, in case of SARS-CoV-2 it amounted to about 2.5 when the pandemic began. It stands at 12 for measles and in the case of chickenpox, to which a number of researchers compare it, it takes an intermediate value. There is data showing that the Delta antigen variant has greater contagious capacity but there is also data about lesser virulence. We'll see how the virus will mutate further.
Q.: Could it turn out that we produce vaccines and the virus mutates further, we produce even more vaccines and it mutates even further, and we start playing catch-up? Is it known how this will end?
A.: This is a general process. Take for example flu and other infections with a changing causative agent. Yes, we will have to keep up with the pace of changes in viruses and today flu vaccines are made with regard to the virus mutations. The WHO gives recommendations regarding the strain content of flu vaccines twice a year, for the Southern and Northern hemispheres. In general, the standoff between viruses and microorganisms and humans has lasted for the whole of history and regrettably humans have not always come out on top. Sometimes microorganisms evolve very quickly and not always perceptibly by humans. In past years, much attention has been paid to the system of improving global biological monitoring and forecasting the development of the epidemiological process of infectious diseases, especially airborne ones, in order to make medicines and especially vaccines with regard to the circulating variant of the causative agent.
But the Chinese have given us hope. There are publications saying that they are going to make a universal coronavirus vaccine. Keeping in mind that a vaccine containing a receptor binding domain (RBD) is unable to cause lengthy protective immunity, researchers have developed an interferon (IFN)-armed RBD dimerized by immunoglobulin fragment (IRF) in order to make the antigen processing and cross presentation in draining lymph nodes stronger.
By the way, as far as flu is concerned, similar studies to create a universal vaccine against all possible antigen variants of the virus are being made. So, coronavirus is not an exception. Yes, it is very important to monitor changes in a timely manner, and be prepared to change the content of both vaccines and medicines. Thankfully there is no such need so far, as the virus variation doesn't affect the profound antigen content and all current vaccines protect from all variants of the circulating virus.
Q.: Does this mean that the current vaccines are effective against this variant?
A.: Yes, there is such data in foreign publications and our home data proves this as well. Maybe, their extent differs because there are very many vaccines now. I guess there are 26 generally used vaccines and more vaccines on new platforms are being made. In the majority of cases vaccines protect against the disease but mainly from severe forms of the disease. A vaccine doesn't prevent an infection, it cannot prevent the virus from getting into the organism, but it prevents the disease and primarily severe forms of it – this applies to all current vaccines, and not only in the Covid-19 context.
Q.: It seems that the probability of a severe form of the disease is lessening even if current vaccines are used?
A.: It is lessening considerably. There are many publications to this end. Those vaccinated have milder illness than those who are not vaccinated and mortality rate is much lower for them.