Why would someone who is fully vaccinated still catch the corona?

Health officials have expressed concern that people who blink lose more confidence in their immune system, remove masks and the epidemic has already returned to some of their habits. And the result can be an infection.
But a week after completing the vaccination program, don’t people become immune to coronavirus?
There are many reasons why someone develops COVID-1 after vaccination, according to a professor of biomedicine and cancer research at the University of Tel Aviv. According to Jonathan Gershoni. The first reason is that clinical trials for Moderna and Pfizer suggest that the vaccine is 95% effective in protecting against the disease. According to Johns Hopkins University, one in 20 people vaccinated may not be safe and may still be ill. The effectiveness of protection is actually calculated based on the number of people. Infected in clinical trials, not on the total number vaccinated.
The second reason is variables.
Pfizer and Moder vaccines were developed based on the original coronavirus strain, as discovered in Wuhan, China, and genetically modified, respectively. Since then, the virus has recurred and mutated into thousands of different types, some of which present the vaccine less effectively.

“We in Israel know that now, most of the infections are from the UK currency,” Gershoni said.
While these vaccines have already proven to be very effective against the UK variant, they are not so effective against South African stress, Gershoni said. Furthermore, he added, there may be other types that are vaccine resistant.
Another reason is that the immune system is a “game of numbers,” the scientist explained.
The disease – or vaccine – causes our body to develop antibodies against the virus. But if a person has an extremely high viral load and it sheds a powerful load, it is likely that this large amount of the virus can break the existing defense and infect the person. However in this case, it potentially causes only mild disease.
After all, everyone is unique and has their own molecular immune system.
“We know that some people are very strong and have a tendency to resist infection, and others may be a little more susceptible,” Gershoni said. “When it comes to vaccinating five million people in Israel, you’re looking at the full spectrum of people with different levels of immunity.”
But he warned that when we talk about “breakthrough infections”, sometimes people get their second dose or even get infected for the first time.
“Someone has to put it in perspective,” Gershoney said. “People who usually feel infected are not subject to devastating disease and death.”
This statement that vaccination makes most of the progress because mild disease is supported by the latest data from the Ministry of Health. Of the 3,387,340 people who were fully vaccinated against coronavirus (two doses plus seven days), only 4,711 caught the virus, or less than 0.2%.
Of those, only 907 people had any symptoms, of which 429 were hospitalized, 271 of whom developed severe cases of the disease.
According to the health ministry, 99 people have died after being fully vaccinated.
Gershony compared the vaccine to the Iron Dome, which saved the country from thousands of rockets and missiles, but missed a few.

“I don’t think anyone in Israel would say let’s leave the Iron Dome because it’s not 100% efficient,” he said. “Similarly, vaccinations are surprisingly effective, but nothing is ever 100%.”