Brazil refused to buy Sputnik V because of the “live” adenovirus, which can cause infection in humans. What?! Is Sputnik dangerous?
On April 26, the Brazilian Agency for Sanitary Inspection ( ANVISA ) issued a press release announcing the ban on imports of Sputnik V into the country. The department explained this by the fact that experts found in the lots a “live” adenovirus, which can multiply and theoretically cause infection in humans. The Russian side completely rejected this possibility. As it turned out, the Brazilian experts themselves did not conduct the research, but were guided by the documentation provided by the Russian side. However, the risk of this problem, apparently, exists due to the technology chosen by the developers of Sputnik. Meduza understood the dispute.
What did the Brazilians find?
Authorities of several provinces asked for permission to purchase the Russian vaccine. The press release was accompanied by presentations with reports from three Brazilian regulators who participated in the examination, and the issue itself was considered online for several hours and was posted on YouTube.
According to the report and the presented presentations, the Russian side sent a package of documents to Brazil, and the experts did not find in it “technical documentation that would guarantee the quality, safety and efficacy of the vaccine.” The release says that because of this, the experts were forced to collect the missing information from various sources, including personally visiting two places of vaccine production: at the site of the Generium company in the Volginsky village of the Vladimir region and at the Pharmstandard production facility in Ufa, the plant “UfaVIT”. The presentations say that experts were not allowed into production at the Gamaleya Center in Moscow.
The report summarized several deficiencies found in the research, production and administration procedures of the vaccine.
- the lack of a clear procedure for registering the disease in the volunteers who participated in the efficacy study (which Meduza has already written about ),
- the actual absence in Russia, where the vaccine has been used for the longest time, of an effective pharmacovigilance system. With its help, it would be possible to track the appearance of undesirable side effects after the start of mass vaccination.
However, the most important drawback of the Russian vaccine, according to ANVISA experts, was the detection in it of replicating, that is, capable of multiplying and infecting human cells, adenoviruses – RCA.
Although the Sputnik V vaccine is based on adenoviruses, it should not contain viable adenoviruses themselves. Those virus-like particles that are contained in a vaccine (in fact, they are a vaccine) can only enter human cells once and force them to produce an antigen – the S-protein of the coronavirus. They cannot multiply, therefore, as a result of such infection of human cells, the appearance of new viral particles does not occur. Replicating adenoviruses in a vaccine are foreign components in a medical product.
Here’s what the ANVISA press release says:
The greatest concern, based on the assessment of the data known to date, is that the cells used to produce adenoviruses are capable of replication. It can lead to human infection and cause injury and death, especially among people with low immunity and breathing problems, along with other medical conditions.
The presentation ( .pdf ) of the General Directorate for Medicinal and Biological Products (GGMED) even more specifically states that RCA are found in the vaccine (slide 6):
Replicating adenovirus detected in all lots of component II of the Sputnik V vaccine: possible recombination. Component I has not been tested for the presence of replicating adenovirus
What did the Sputnik developers answer?
The ANVISA report attracted the attention of leading scientific journalists and experts, who called the discovery of replicating adenoviruses in the vaccine an unpleasant surprise , which “although it should not cause great problems for the vaccinated, leads to a completely unnecessary risk.”
Science columnist Derek Loewe suggests that replicating adenoviruses by themselves are unlikely to be a problem for vaccinated people, although they pose a completely unnecessary risk for the vaccine. Molecular biologist Konstantin Severinov, with whom Meduza spoke, agrees with him.
Professor of Skoltech and Rutgers University, molecular biologist Konstantin Severinov
Adenoviruses cause mild respiratory illness that occurs after the virus enters the epithelial cells of the nasopharynx. When injected intramuscularly, hundreds or even thousands of adenoviral particles, which, apparently, can be in the dose of the Russian vaccine, are unlikely to lead to any serious complications. In extreme cases, there may be some slightly more severe side effect, which, however, was not identified during clinical trials. So I don’t think this is a big problem.
The very next day after the ANVISA report, the Russian Direct Investment Fund (RDIF) – the main investor and exporter of vaccines – issued a statement refuting the key claims of experts. The developer claims that the Brazilians “had full access to all relevant documents, production and development centers … as well as direct access to the researchers at the Gamalea Center responsible for the development of the vaccine.”
Regarding the main issue – replicating adenoviruses – the response states that “The Gamalea Center maintains strict controls at all Sputnik V production sites and has confirmed that there is no replication-capable adenovirus (RCA) in all lots of vaccine produced.” This, according to RDIF, is also stated in a letter sent to ANVISA experts even before the start of their work – on March 26, 2021.
And who is right?
The small Brazilian edition Super Interresante managed to partially clarify the situation and resolve the clinch “the word ANVISA versus the word RDIF”, which requested a comment from the regulator of its country. ANVISA admitted to journalist Bruno Garratonni that in factexperts in Brazil did not conduct any tests for the detection of replicating adenovirus. All of their conclusions, quoted above, are based on reading the documentation provided by RDIF itself.
ANVISA refused to provide copies of these documents to the journalist, citing the fact that they belong to RDIF. However, Garratonni drew attention to the fact that the Brazilian experts in their report mention the discrepancy between the sensitivity of the tests given in the documentation and the sensitivity adopted by the American FDA standards for genetic drugs (these standards are obviously chosen as a guideline). According to him, it is this discrepancy between the sensitivity standards for RCA tests, as interpreted by ANVISA experts, has turned into “detection of adenovirus in all lots.”
Two sources for Meduza, familiar with the details of the manufacturers working with the Gamaleya Center, argue that this type of testing is not done at the vaccine production site. For him, as well as for quality control in general, the Gamaleya Center itself is fully responsible, which also supplies the initial cell culture for cultivation.
On the night of April 30, ANVISA experts spoke at a new press conference , where they actually confirmed Garratonni’s rightness. Brazilian experts not only reiterated their initial statements, but also provided excerpts from the dossier, which led to the conclusion that RCA was present in the vaccine. In addition, excerpts from video recordings of consultations with RDIF representatives were also presented at the press conference.https://www.youtube.com/embed/fCtCvc5dib0?start=1&feature=oembedANVISA Statement on Sputnik V Vaccine, 29 April 2021Agência Nacional de Vigilância Sanitária
The main author of the report, Gustavo Mendes, explained how the conclusion was made about the presence of RCA without performing his own laboratory tests: it was based on a comparison of data from the quality certificate of several lots of vaccine and similar data for placebo.
In the first case, the documents indicated that the drug contained RCA in an amount of less than 100 units with the indicated maximum permissible value of 1000 units, and in the documents on the placebo in a similar position it was written that replicating adenoviruses were not detected at all.
When we compare the results of placebo tests, that is, a product that does not contain a vaccine, does not contain a virus, the results show a zero result, “not found.” When we study by the same method, by the same procedure, the results of the analyzes of the vaccine, we find the “presence” as in the specification. This specification [maximum allowable] implies an amount 300 times higher than the FDA [for gene therapy] guidelines. <…> The specification requires “no more than 1 × 10³ of replicating adenoviruses per dose,” and the result is less than 1 × 10² of replicating viruses. These numbers must be zero. In the case of the placebo, as I said, this same specification shows that the assay gave zero results. ( from 13:46 )
It is important to note, however, that Mendes cites the FDA value for adenovirus-based gene therapies as a guideline, not for adenovirus vaccines. The carrier viruses that are used can be very different, so it is not clear whether it is fair to apply the norms of some drugs to others.
As far as Meduza was able to find out, there are no generally accepted norms that regulate the level of RCA in adenovirus vaccines, apparently due to the small number of such vaccines.
Where could an extraneous virus in Sputnik come from?
So that the adenovirus, which becomes the carrier of the S-protein of the coronavirus, cannot multiply uncontrollably in the body of the vaccinated, it is deprived of the gene necessary for reproduction. However, during production, such viruses must still somehow multiply – for this, the required gene is inserted into the cells in which it is grown. Sometimes this “multiplication gene” can jump back from the cell to the viral particle through a phenomenon called recombination. The probability of a jump depends on what cells are used in production – in the production of Sputnik V, this probability is relatively high, and in the production of AstraZeneca and J&J vaccines, it is lower. The use of the technology that is used in the production of Sputnik V is not a violation of the generally accepted standards for the production of adenoviral drugs, but a decision which poses some additional risks. At the same time, as already mentioned above, there is no reliable reason to believe that the replicating adenoviruses in the vaccine can somehow affect the health of the vaccinated.
The answer is more complicated
Adenovirus capable of replication (if it is actually present in the vaccine) could get into it in two fundamentally different ways: through non-compliance with sterility conditions or naturally – through recombination.
Failure to maintain production sterility seems unlikely, since in this case adenovirus is the smallest problem a manufacturer can face. Infection of the culture with bacteria or fungi and the complete loss of the produced drug is much more likely than the imperceptible entry into the culture of a “pure” adenovirus.
The second route is recombination, which is much more likely and is considered an important problem in the production of adenovirus vaccines and genetic constructs. “Russian developers, having the opportunity to use such cells for the production of a vaccine virus, in which recombination (that is, gene exchange) does not occur, nevertheless took a somewhat outdated design – which became the source of problems,” believes Konstantin Severinov.
In short, the problems are as follows. When developers decide to use a viral vector to deliver antigen, they can go in two ways: leave the virus with the ability to multiply in human cells or completely deprive it of this ability – for example, by removing the genes necessary for this. Usually, researchers go the second way, as this allows for additional safety of the drug. In this case, it is necessary to sacrifice the duration of immunity, because a non-multiplying vector quickly disappears from the body and the immune response received for the antigen contained in it may be too weak .
However, in production in cell culture, the virus must nevertheless multiply efficiently and quickly even without the genes necessary for this. To solve this problem, the deleted genes are introduced into the genome of the cell culture itself, which grows in a reactor in production – in which the virus can behave in the usual way. Once in the human body as part of the vaccine, the same virus will no longer be able to “take” the required gene from the host cell, therefore it will not be able to multiply.
The problem is that sometimes – quite rarely – due to the similarity between the fragments of the genome of the vector virus and the “propagation genes” removed from it, an exchange of genetic material between the cell and the virus can occur – recombination. As a result of such an exchange, a virus, deprived of genes necessary for reproduction, can get them back – often with the loss of a gene that acts as a “payload”. The probability of recombination is not very high, but in the case of long-term production, it is non-zero. It depends primarily on the length of the matching sequences between the genome of the virus and the genome of the modified cell.
And it is here that the features of the device and production of the Sputnik V vaccine come to the fore. Judging by the information from the patent , it belongs to the very first generation of adenoviral vaccines , in which replication is blocked by removing the adenoviral E1 gene and transferring it into HEK293 cells. Back in the mid-1990s, it was discovered that, in this case, the formation of RCA is relatively often possible – precisely due to the recombination between fragments of the E1 gene and the DNA regions remaining after its removal from the viral genome.
To combat this phenomenon, other cell lines have been developed to replace HEK293. This is, first of all, PERC.6 with a special genetic construct containing the E1 gene, with which such a recombination does not occur. It is this cell culture that is used in the production of a vaccine from Johnson & Johnson, which is very similar to the first component of Sputnik.
The use of an older cell culture in the case of Sputnik does not, of course, imply a breach of the production procedure or an obvious mistake: each cell line has its pros and cons in terms of production. Another adenovirus vaccine, produced by AstraZeneca, for example, is also grown on HEK293, but the AstraZeneca vaccine is not based on a human virus, but on a chimpanzee virus – and it is almost unable to recombine with the genes of the human coronavirus in HEK293.
Nevertheless, in the case of Sputnik, the use of HEK293 in combination with the classical approach to the creation of an adenoviral vector virus is guaranteed to imply the possibility of recombination. This means that the need for careful control of this risk in production. The details of exactly how this control is organized in the case of “Sputnik” are currently known only to the manufacturer himself.