Scientists from Uzbekistan have obtained milk with antibodies to SARS-CoV-2 by vaccinating cows and goats against coronavirus. They hope that such milk will allow for passive immunization of the population. Rospotrebnadzor agrees that the drink may be useful for prevention, but they are sure that a large number of studies are needed to confirm the effectiveness and safety of the product. Virologist Pavel Volchkov believes that the effect of milk will be limited and not effective enough. Researchers from the Ministry of Innovative Development of the Republic of Uzbekistan have proposed using milk with antibodies from goats and cows vaccinated with human vaccines as a prophylactic against COVID-19. They reported on the prospects of such a method in an as-yet-unreviewed article posted on the bioRxiv preprint service.
The slow pace of mass vaccination and the emergence of new variants of SARS-CoV-2 increase the risks of infection, so additional measures are needed to protect as many people as possible, the authors of the work explained.
They noticed that women who had been vaccinated or recovered from COVID-19 had antibodies to SARS-CoV-2 in their breast milk, and suggested that milk from cows and goats vaccinated against COVID-19 could be used to immunize the population./i
During lactation, both in women and in cows, various antibodies in sufficiently high concentrations enter the milk, Pavel Volchkov, head of the MIPT genomic engineering laboratory, confirmed.
“Indeed, the milk we consume contains antibodies,” said Volchkov. - If you immunized a cow or a goat with some kind of coronavirus vaccine, then it will contain a significant amount of antibodies to the coronavirus. In addition, cow’s milk normally contains other antibodies, mainly to cow pathogens.”
The authors of the work vaccinated domestic goats and cows with a vaccine intended for humans three times: the second time on the 28th day after the first vaccination, the third time on the 56th day.
Neutralizing antibodies were detected in the serum two weeks after the first vaccination. Experiments on cell cultures have shown that antibodies successfully neutralize SARS-CoV-2 - in blood serum, the efficiency reached 100%, in milk - 40%.
“The blood serum and milk of the vaccinated cow contained specific IgG to the SARS-CoV-2 receptor-binding domain and S-protein,” the authors wrote.
In addition, antibodies were able to persist after pasteurization, which makes it possible to prepare immunized milk in large volumes.
“The first results of experimental testing showed that the human ZF-UZ-VAC2001 vaccine can be safely used to vaccinate domestic farm animals in order to obtain immunobiologically active milk and whey containing specific neutralizing antibodies against SARS-CoV-2,” the authors concluded. They hope that the milk produced in this way can be used for mass passive immunization of the population.
However, in the case of coronavirus, the effectiveness of such immunization is doubtful - antibodies are unlikely to be active outside the gastrointestinal tract, Volchkov noted.
“Antibodies are contained in milk, we consume milk - that is, everything related to the gastrointestinal tract will somehow be neutralized,” he explained. - In fact, there will be a neutralization of viruses at the level of the gastrointestinal tract. It probably makes sense to do this in relation to viruses that spread exactly through the gastrointestinal tract.
Another thing is that the main route of infection is the upper respiratory tract. And then with milk, except to gargle.
Thus, immunized milk can be considered as a way to prevent coronavirus infection. An already infected person, most likely, such milk will not help in any way.
“Another thing is that these antibodies can be isolated from milk,” added Volchkov. - But then the cow should not secrete cow antibodies, but humanized, human ones. Then it is necessary to genetically modify the cow so that the constant fragments of antibodies are human, not cow. This is if we want to get antibodies, which can then be injected somewhere.”
Ready-made antibodies have long been used in medicine for the treatment of various diseases, primarily in severe cases, said the deputy director for clinical work of the Moscow Research Institute of Epidemiology and Microbiology. G.N. Gabrichevsky Rospotrebnadzor, Doctor of Medical Sciences Tatyana Ruzhentsova and Leading Researcher of the Laboratory of Immunobiological Preparations of the Moscow Research Institute of Epidemiology and Microbiology named after A.I. G.N. Gabrichevsky Rospotrebnadzor, candidate of medical sciences Alexander Volkov.“At the beginning of the 90s of the last century, at the Moscow Research Institute of Epidemiology and Microbiology, under the guidance of Professor Vladimir Andrianovich Aleshkin, the technology of oral (that is, through the mouth) application of human antibodies was developed and put into practice. CIP is a complex oral immunoglobulin preparation, which is a mixture of antibodies, and is still successfully used to treat acute intestinal infections.
Studies have confirmed that antibodies are not destroyed in the gastrointestinal tract and retain their properties when taken orally,” the experts explained.
However, foreign antibodies, as active protein molecules, can cause a number of immunopathological reactions, including adverse reactions when consumed by a person infected with the coronavirus, they warned. Therefore, for antibodies obtained as a result of vaccination of cows and goats, it is necessary to conduct a large number of studies that can confirm their effectiveness and safety, the department noted.
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