Because previously, a paper published by American researchers showed that after adding reverse transcriptase, COVID-19's RNA can be reverse transcribed into DNA in vitro cell experiments and integrated into the genes of human cells.
Will COVID-19's RNA be integrated into human DNA? Will the inoculation of mRNA vaccine really lead to genetic changes in human body? The Science and Technology Daily reporter interviewed industry experts for this purpose.
COVID-19's genes will not be integrated into the human body.
Viruses are divided into DNA viruses and RNA viruses according to their nucleic acid components. It is reported that more than 200 viruses are known to infect humans.
Scientists have found that about 8% of the human genome today comes from viruses. "The virus with this ability is an ancient retrovirus. Retrovirus will integrate nucleic acid into the host genome, and the host cell will copy the viral nucleic acid as a part of itself, and produce protein to assemble new viruses. This process is equivalent to the virus hijacking the host and turning itself into a member of the host family. Hepatitis B virus is a DNA retrovirus, and it is usually difficult to remove such viruses. " Wang Chenguang, Ph.D. in biology and former professor of Peking Union Medical College, said.
Does COVID-19 have this ability? "Although COVID-19 is similar to a retrovirus (single-stranded RNA virus), it is not a retrovirus, and their behaviors after infecting the host are essentially different. After COVID-19 infected the host cell, he existed as an' alien', but he was well disguised and was entertained by the host to eat and drink-the viral nucleic acid was replicated in the host cell, expressed in protein, and finally assembled into virus particles, but he did not hijack the host. " Wang Chenguang explained.
Zhang, an associate professor in the Department of Pathology and Experimental Medicine, University of Pennsylvania School of Medicine, also pointed out in an interview with Science and Technology Daily that COVID-19 is an RNA virus, but it is not a retrovirus, so it is common sense that the gene will not be integrated into human chromosomes.
Inoculation of mRNA vaccine will not cause genetic changes in human body.
"Since COVID-19's genes can't change human genes, the mRNA vaccine made from the gene fragment of COVID-19 S protein will not be integrated into the human body after vaccination." Zhang said, "What's more, the chromosomes carrying the human genome exist in the nucleus, and the nucleus is wrapped in a nuclear membrane. For the mRNA vaccine, the nanoparticle carrier of the vaccine only sends the virus gene fragment into the cytoplasm, but does not enter the nucleus at all. How can you integrate into the human genome if you can't even get into the nucleus? Therefore, there are a lot of concerns about the gene integration of mRNA vaccine. "
For the conclusion of the paper published by American researchers mentioned above, Zhang thinks that this is just an in vitro experiment, which happened in a cell culture dish, not what really happened in the human body. In vitro experiment can be used as a bold exploration, but in terms of treatment and prevention, in vitro experiment can not be simply regarded as a creed.
Wang Chenguang explained that COVID-19 mRNA vaccine only contains the nucleic acid sequence encoding virus protein, and then human cells use their own components and the template of virus mRNA to synthesize protein. Its viral nucleic acid substance has not been integrated into the genome of human cells, nor has it been replicated and amplified in cells. Instead of being hijacked by viruses, the cells used their own synthetic protein to train a group of "mercenaries" and then used them to guard against the invading enemy-COVID-19.