“Stopping the transmission of the virus”: the Gamaleya Center spoke about the features of the nasal vaccine against COVID-19

- Vladimir Alekseevich, how soon will the nasal vaccine against the Gam-COVID-Vak coronavirus, which was registered by the Ministry of Health in early April, become available to Russians?

- It will depend on how quickly the manufacturing companies will start production and supply a sufficient number of doses of the vaccine.

I note that the nasal vaccine is actually the same previously developed Sputnik V drug, only in the form of a nasal spray.

This application allows the formation of mucosal immunity - mucosal immunity.

Its presence can at the very beginning block the very penetration of the virus into the human body.

To date, preclinical studies have been carried out, as well as the first phases of clinical studies.

They showed that the drug has a low reactogenicity and at the same time has immunogenicity.

This means that as a result of the use of the drug, we get an immune response that can protect a person from infection.

This vaccine should show its effectiveness precisely at the moment of a person's encounter with the virus.

The vaccine has received registration, it can already be used to protect people.

But this does not relieve us as developers of the obligation to continue clinical research on the effectiveness of the drug.

Of course, we expect that we will be able to prove the effectiveness of the vaccine, that it can be widely used.

• Head of the Laboratory of Mechanisms of Population Variability of Pathogenic Microorganisms, National Research Center for Epidemiology and Microbiology named after V.I.

  N.F.

  Gamalei of the Ministry of Health of Russia Vladimir Gushchin

• © National Research Center for Epidemiology and Microbiology named after N.N.

  N.F.

  Gamalei of the Ministry of Health of Russia

- Does the nasal vaccine require special storage conditions, deep freezing?

No, this vaccine is not

requires some special storage conditions.

Freezing at -20 °C or + 4 °C, standard for vaccines, is sufficient.

Such conditions can be provided by standard refrigerators, which are used for immunobiological preparations.

- How will vaccination be carried out - through polyclinics, like injectable Sputnik V?

Or the vaccine can be bought at the pharmacy?

- Today it is more correct to say

on the use in the standard network of vaccine cabinets.

Because we are talking about an innovative drug that is just beginning to be used.

It is necessary to gain the practice of effective use; at first, a more careful attitude is required both to the drug and to the patients who receive it.

I do not rule out that in the future the approach may change, but for now it is advisable to use this vaccine in medical institutions.

In any case, the nasal form of the drug can simplify the vaccination procedure and increase vaccination coverage.

There are many people who would like to receive a nasal vaccine.

- Do I need to somehow prepare for such a vaccination - rinse the nose, for example?

And is it necessary to observe the precautions that are taken during conventional vaccination: not to be vaccinated during other diseases, not to drink alcohol, etc.?

— There are standard recommendations for all immunobiological preparations.

Vaccines should not be used under extreme stress conditions.

These are strong sports loads, and going to the bathhouse, and the use of drugs that reduce the immune status ... These are standard requirements and standard practice.

At the time of vaccination, a person should be alert, sober, healthy, he should not have any infectious disease.

- You mentioned the bath, is it also a strong load on the body?

—

Of course, because we are talking about finding a person in extreme temperatures.

The same applies to large sports loads, all this can affect a person's condition after vaccination.

True, most people in everyday life are still not subjected to extreme stress, so they have nothing to worry about.

• Operation of the Coronavirus Vaccination Center

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- Will the tests for coronavirus antibodies that are currently used in clinics show the antibody titer after nasal vaccination?

Two types of tests are now widely used: diagnostic, to assess the amount of immunoglobulin class G (IgG) antibodies to the coronavirus N-protein.

The second type of test determines the amount of antibodies of class G immunoglobulin to the S-protein of the virus or to its fragment, the receptor-binding domain.

Tests of this type are used to determine the presence of antibodies not after an illness, but after vaccination.

And they will be applicable to detect antibodies produced by the body after the application of the nasal form of the vaccine.

It is expected that after its application, the antibody titer should increase.

Of course, it is most interesting for researchers to find out how the immune status changes directly on the mucosa, at the site of the vaccine.

Such tests also exist, but they are not yet widely distributed.

Therefore, in most cases, standard tests will still be used, which were previously used to change the antibody titer after vaccination.

- Will these figures correspond to the titers from the injectable vaccine?

Or will a new scale be required in this case?

- In fact, such a scale does not exist.

There is only a scale according to which you can talk about a positive or negative test result.

And that baseline would apply to the nasal vaccine as well.

And if we talk about the level of antibodies in international BAU units, then these indicators cannot measure many components of the immune status - for example, class A immunoglobulins (IgA), which ensure the functioning of immunity on mucous membranes, as well as cellular components that are also involved in the immunity of mucous membranes.

Tests that would routinely assess the level of this class of antibodies specifically on mucous membranes are currently not widely available.

Perhaps, over time, tests will appear that evaluate the titer of class A immunoglobulin in the blood.

• SARS-CoV-2

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— Indeed, mucosal vaccines are of great interest to all researchers; work on such drugs is being carried out in many laboratories.

This is a new class of drugs - in fact, most vaccines were previously developed for intramuscular or subcutaneous administration.

This method allows to form a sufficient protective immune response.

It was right to start the development of vaccines against coronavirus with classical administration drugs, which provide the most reliable, predictable result.

As we know, such vaccines are now working well, although they have somewhat decreased their effectiveness against primary infection due to the emergence of new strains of the virus.

Although they can still significantly reduce the likelihood of hospitalization and the severity of the disease, this has already been proven.

Now we are faced with the task of offering a drug aimed precisely at stopping the transmission of the virus from person to person.

We need a vaccine that would protect people at the stage of primary infection.

The nasal vaccine is such a drug - its widespread use should reduce the very spread of the virus in the population, and not just the number of hospitalizations.

- Is the nasal vaccine able to replace the injection vaccination?

If not, how should they be alternated, with what frequency?

- That's a good question.

To date, we have much more data on the injectable form of the vaccine than on the nasal form.

Hundreds of millions of doses of the Sputnik V vaccine have been applied, there are comprehensive statistics on the safety and effectiveness of the drug, it is very well studied.

As for the mucosal version of the vaccine, it has so far received initial approval based on limited clinical trials.

And it’s too early to talk about replacing the nasal vaccine with an intramuscular vaccine.

In the future, when the same comprehensive data are obtained for the nasal vaccine, it will be possible to raise the question of abandoning the intramuscular vaccine, but not now.

We know for sure that the intramuscular vaccine works, we know how long and how exactly it protects people.

There are still questions to be answered about the nasal vaccine.

I really hope that such data will be collected in the coming months.

So far, there is reason to believe that the greatest effect can be achieved by using the injectable and nasal form at the same time.

Many people who have been previously vaccinated will now be able to get a nasal vaccine as a booster.

And further observations will tell you in what order with intramuscular vaccination it is best to use this drug.

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- The nasal vaccine must form a barrier to the virus so that infection does not occur.

But if the pathogens still get into the body of a person vaccinated with it, will it protect against the development of the disease?

— As conceived by the developers, the vaccine will be effective at the time of primary infection.

If the mucosa is ready for the appearance of a pathogen, the body's response will be lightning fast.

Now research is ongoing, it is clear that in a certain percentage of people the vaccine may not prevent infection.

However, if the barrier effectiveness of the nasal vaccine is higher than that of the injectable form of the drug, this will be exactly the result that we are seeking.

- But in any case, the antibodies that we talked about earlier, which can be detected using test systems, will they help in the fight against the virus if it does enter the body?

—

Undoubtedly.

Because as a result of the use of a nasal vaccine, immunity is formed not only on the mucous membrane.

It will also be expressed in the appearance of antibodies, immunoglobulins of class G in the blood. Here we should talk about in which direction the balance is shifted, towards mucosal immunity or systemic immunity.

In the case of the nasal vaccine, the balance is shifted towards mucosal immunity, the formation of IgA antibodies.

In general, now there are fewer and fewer people who have never encountered a coronavirus antigen - have not been vaccinated or have not been sick.

Therefore, the nasal vaccine for most people will have a boosting effect.

- Earlier it was reported that the Gamaleya Center has plans in the future to create a nasal vaccine for children.

When is the clinical trial supposed to start?

- The classical scheme for the introduction of any immunobiological drug implies that the vaccine must first pass all stages of testing on adults.

And we are at that stage right now.

Once we have conclusive data on the efficacy and safety of a drug in a broad adult population, we can move on to testing the drug in adolescents and children.

So it all depends on how effective the vaccine will be when applied to adults.

If it is high, then work on a similar drug for children will begin in the near future.

Perhaps we will talk about the selection of a special dosage for children and adolescents, as was the case with the injectable form of the vaccine: for adolescents, it was reduced by five times in order to obtain the optimal balance of reactogenicity and effectiveness.

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Does the registered nasal vaccine protect against new strains of coronavirus?

- To begin with, we know how the intramuscular vaccine works with respect to new variants of the virus.

It is already known that efficacy is preserved especially well if a person after primary vaccination received one or two booster doses of the drug six months later.

In the case of the nasal preparation, we have evidence that the vaccine is safe and immunogenic.

But to date, we do not have enough data to say how effective the nasal vaccine is, especially in relation to possible future variants of the coronavirus.

But we will study this issue, see how the vaccine will show protective properties against new variants of the virus penetrating the population.

And we will publish the results of these studies.

- Were there any side effects after using the nasal vaccine?

- The data that we have

suggest that the vaccine has an acceptable level of safety.

There is some reactogenicity, but it is not something special and alarming.

It can already be said that the vaccine does not cause any serious adverse events.

Therefore, it is approved for use.

- That is, in fact, the side reactions were the same as in the case of the injection form?

- Yes, in general, they are the same - a rise in temperature is possible, a kind of flu-like syndrome.

Of the benefits - the injection site does not hurt, because it does not exist.

But on the other hand, local reactions on the mucous membrane may occur: dryness in the nose, runny nose.

- Now the incidence of coronavirus is on the decline, in a number of regions and countries have already canceled sanitary restrictions.

Should I continue to get vaccinated against COVID-19?

“I don’t think that any evolutionary biologist in the world will take the responsibility to ensure that some new variant of SARS-CoV-2 does not appear in the near future, more dangerous than the “omicron”.

There are no guarantees that, for example, the “delta” option will not return.

What we can say for sure is that people who have strong immunity to coronavirus are much better protected even if new variants of the pathogen appear.

To do this, you need to regularly undergo revaccination.