Vaccines don't block viruses. They're not brick walls.
They just provide your body with the training to fight severe illness.
Saying that, Pfizer expects an omicron specific vaccine by March, and Moderna's not far behind.
They may not block them, it is better said the mRNA vaccine causes the body to make Antibodies that recognize the Covid virus, attach to the Covid virus, marking the Covid virus for destruction. In other words the the mRNA vaccine don't fight or block the virus at all it, the vaccine just gives our bodies the information to allow our own bodies to fight the virus.
For people that might want to know if they don't already below is how the mRNA vaccine work, if a person doesn't care don't read it:
From NYU Langone Health:
Viruses can’t reproduce themselves. They need a host. The coronavirus uses a spike protein to gain entry into the cells and start the replication process that makes us sick. In developing mRNA vaccines, scientists zeroed in on a unique spike protein that is found on the surface of the virus. On its own, this spike protein is incapable of causing COVID-19.
The mRNA vaccines work by relaying a set of instructions for how to build this protein, with the goal of teaching your immune system how to disarm it.
This from the Medline Website:
Most vaccines contain a weakened or dead bacteria or virus. However, scientists have developed a new type of vaccine that uses a molecule called messenger RNA (or mRNA for short) rather than part of an actual bacteria or virus.
Messenger RNA is a type of RNA that is necessary for protein production. In cells, mRNA uses the information in genes to create a blueprint for making proteins. Once cells finish making a protein, they quickly break down the mRNA.
mRNA from vaccines does not enter the nucleus and does not alter DNA.
mRNA vaccines work by introducing a piece of mRNA that corresponds to a viral protein, usually a small piece of a protein found on the virus’s outer membrane. (Individuals who get an mRNA vaccine are not exposed to the virus, nor can they become infected by the vaccine.) Using this mRNA blueprint, cells produce the viral protein. As part of a normal immune response, the immune system recognizes that the protein is foreign and produces specialized proteins called antibodies. Antibodies help protect the body against infection by recognizing individual viruses or other pathogens, attaching to them, and marking the pathogens for destruction. Once produced, antibodies remain in the body, even after the body has rid itself of the pathogen, so that the immune system can quickly respond if exposed again.
If a person is exposed to a virus after receiving mRNA vaccination for it, antibodies can quickly recognize it, attach to it, and mark it for destruction before it can cause serious illness.
Note this says,
"before it(Covid in this instance) can cause serious illness", not that we will not or can not get an illness at all. The gov should of said that right from the start. It's the same for vaccines of many types since their inception. Some citizens grabbed on to people still getting sick after vaccination as demonstrating that mRNA vaccines don't work when in fact it was never said from the start that no one would ever get ill after an mRNA vaccination.It's just not how they work some people immune system wont work as well as others to making the antibodies.