Today, the leading academic journal Science published two important papers on the development of the new corona vaccine: the Beth Israel Deaconess Medical Center, a subsidiary of Harvard Medical School, developed a DNA vaccine that found that the rhesus monkeys produced antibodies and could effectively prevent the infection of the new coronavirus. In addition, they found that rhesus monkeys recovering from the new coronavirus infection can also develop immunity to prevent the reinfection of the virus. These two studies are important for guiding vaccine development and understanding the long-lasting protective effects of antibodies.
In the first study, scientists designed a series of DNA vaccines based on published data on the genome of the new coronavirus. These DNA vaccines express the different forms of the S protein of the new coronavirus (e.g. full-length proteins, or the removal of proteins across membrane domains, etc.). It is worth mentioning that the S protein is also the focus of many vaccine developers today.
It is envisaged that these DNA vaccines, after injection, can produce the corresponding protein in the animal, thus playing a “inoculation” effect, inducing the production of antibodies.
To assess the effectiveness of the DNA vaccine, the researchers used 35 rhesus monkeys for the study, 25 of which were vaccinated against DNA and 10 were in the control group. As envisaged, the vaccine-vaccinated monkeys quickly developed neutralizing antibodies, and the titritage of the antibodies was comparable to that of the body of the recovered patient.
Compared to the control group (Figure A), the viral load of vaccinated monkeys decreased significantly (Figures B and C) (Picture Source: Resources 1)
Three weeks after the vaccination, the researchers exposed the 35 monkeys to the new coronavirus. Subsequent analysis found that the 25 rhesus monkeys who received the inoculation had significantly lower viral loads than the control group. Of the 25 monkeys, 8 were undetected for the new coronavirus, and the remaining 17 were not high. Interestingly, it appears that the higher the antibody level slyly the monkeys, the lower the level of the virus in the body. This suggests that neutralizing antibodies may have a protective effect.
In the second study, scientists modelled the rhesus monkeys with new coronavirus infections and confirmed that they had high viral loads in their upper and lower respiratory tracts. When the monkeys recovered (no new coronavirus in their bodies), the researchers again exposed them to the new coronavirus to see if the monkeys were already immune to the new coronavirus.
The study’s lead author, Dan H. Photo Credit Beth Israel Deaconess Medical Center
“Individuals recovering from a viral infection generally produce antibodies to protect themselves from re-exposure. But not all viruses produce this natural protective immunity. “The two studies’ lead author, Dan H. Professor Barouch said.
Excitingly, nine of the rhesus monkeys tested were found to have antibodies against the new coronavirus after their first infection. And when they are exposed to the new coronavirus again a month after infection, the virus is almost completely protected. These data suggest that, at least in the rhesus monkey model, it is possible to bring its own immunity after recovery.
“The development of new crown vaccines is feasible, and our findings add to our optimism,” Added Professor Barouch. “