Three studies released on Friday showed more evidence that vaccines against the Corona virus can be effective against the mutant Omicron, at least among people who received booster doses.
And health officials in the United States said that this is the first large American study looking at the effectiveness of vaccines against Omicron, according to the agency “.Associated Press“.
The first study dealt with hospitalization cases and the need to enter emergency centers and visit urgent medical care centers in 10 states, during the period from the tenth of August until this month.
The study found that the effectiveness of the vaccine was better in people who received three doses of the Pfizer or Moderna vaccines.
During the delta period, the study says that the effectiveness of the vaccine against the need for hospitalization reached 90 percent after two weeks and up to about 6 months after receiving the second dose.
The percentage decreased to about 81 percent six months after receiving the second dose, but increased to 94 percent after two weeks of receiving the booster dose.
For Omicron, the study showed that the effectiveness of the vaccine during the same periods was 81 percent, 57 percent and 90 percent, respectively.
The second study focused on coronavirus-related death rates in 25 states from the beginning of April to the end of last December.
The study found that people who received a booster dose had a higher level of protection against infection with the coronavirus, during the time when the Delta strain was dominant and also when the dominance shifted in favor of Omicron.
The results of these two studies were published by the Centers for Disease Control and Prevention in the United States.
In contrast, the Journal of the American Medical Association published the third study, which was led by researchers from the Centers for Disease Control and Prevention.
The third study examined the number of people infected with the virus from December 10 to January 1, at more than 4,600 testing sites across the United States.
The results showed that those who received three doses of Pfizer or Moderna had a 67 percent greater ability to cope with symptoms associated with Omicron than unvaccinated people.
The researchers also found that two doses of the two vaccines did not provide significant protection against Omicron.
It “shows the importance of getting a booster dose,” said Emma Accorsi of the CDC, one of the study’s authors.
The results of this study are almost consistent with the findings of researchers in Britain, Thursday, that the third dose provides “short-term” protection and lasts less than “6 months”, but protection from severe symptoms of infection with the Corona virus lasts longer than that.
And these researchers found that after the third dose of the Pfizer vaccine, protection against infection with severe symptoms of corona begins about two weeks after receiving it, and protects the body with an effective rate of 70 percent.
But after about 3 months, this protection decreases, bringing the effectiveness to about 40-50 percent for immunization against severe symptoms of corona.
The highly contagious mutant amicron is spreading widely around the world, prompting some countries to re-impose new measures and speed up the launch of booster-dose vaccination campaigns.