According to a new study, a comparison of four covid-19 vaccines shows that messenger RNA (mRNA) covid-19 vaccines Pfizer biontech and Moderna perform better on World Health Organization (who) variants of concern (VOCs) than viral vector vaccines AstraZeneca and Johnson & Johnson / Janssen** Although they can effectively prevent serious diseases of VOCs, they were published in the open journal [PLoS Medicine] on May 17( https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003991 ) 》Previous studies have shown that people vaccinated with viral vectors are more likely to be infected with new variants.
By March 2022, the total number of covid-19 confirmed cases in the world has exceeded 450 million and more than 6 million deaths. The first batch of vaccines approved in the United States and Europe to prevent severe infection came from Pfizer biontech and Moderna. They transmit genetic code, called mRNA, to the cells of the body, while the vaccines of Oxford / AstraZeneca and Johnson & Johnson / Janssen are virus vector vaccines, which use modified versions of different viruses - vectors - to transmit instructions to our cells. The three vaccines are injected separately at intervals of several weeks, while the Johnson & Johnson / Janssen vaccine is a single injection.
Marit J. van gils of the University of Amsterdam in the Netherlands and colleagues collected blood samples from 165 medical staff three and four weeks after the first and second vaccination, respectively, while blood samples from Johnson & Johnson / Janssen vaccinators were collected four to five weeks and eight weeks after the vaccination. The researchers collected samples before and four weeks after Pfizer biontech booster vaccination.
Four weeks after the first two doses of vaccine, people vaccinated with Moderna had the highest antibody response to the original sars-cov-2 virus strain, followed by Pfizer biontech vaccine, and the number of people receiving virus vector vaccine was greatly reduced. Tests on VOCs -- alpha, beta, gamma, Delta and Omicron -- showed that people receiving mRNA vaccine had higher neutralizing antibodies than those receiving viral vector vaccine. The ability to neutralize VOCs decreased in all vaccine groups, especially for Omicron. Pfizer biontech's booster needle improved the antibody response of all groups, and greatly improved the antibody response to VOCs (including Omicron).
The researchers cautioned that their AstraZeneca group was significantly older because of concerns about the safety of the vaccine among young people. Since the immune response tends to weaken with age, this may affect the results. This group is also relatively small because the Dutch government stopped using it for some time.
"The antibody responses induced by the four covid-19 vaccines are very different," Van gils concluded