Quick Facts

• Vaccines cause the immune system to create new cells and molecules that recognize a germ without getting sick. When the body encounters the germ later, the immune system recognizes it and is ready to fight it off.
• Three vaccines have been approved by the FDA for Emergency Use in the US: two are mRNA vaccines from Moderna and Pfizer/BioNTech, and one is a viral vector vaccine from Johnson & Johnson/Janssen
• All three use technology that differs from previously approved vaccines, but the technology itself is not new
• DNA is the molecule that stores genetic information in cells. DNA must be “transcribed” into mRNA. DNA is stored in the cell nucleus.
• mRNA is a short length of nucleic acids that encodes a protein. mRNA molecules are produced naturally by the body, and must be “translated” into proteins in order for the cells to produce the proteins you need to live. mRNA must be transported into the cell cytoplasm before it can be translated into proteins.

Didn’t they need to cut corners  to get the new vaccines approved so quickly?

It’s true that the SARS-CoV-2 vaccines are the fastest vaccines ever approved (the previous fastest was the mumps vaccine in the 1960s, which took 4 years).

That said, scientists have been working on vaccines targeting similar viruses for years (remember SARS and MERS – they are also caused by coronaviruses), so they had somewhat of a head start on vaccines for SARS-CoV-2. Scientists knew from previous research that the spike protein would be the key to developing an effective vaccine, so they weren’t starting from square one.

But Aren’t mRNA vaccines brand new technology?

mRNA vaccines aren’t actually new. Even though there has never been an mRNA-based vaccine approved before, we’ve been working on creating these for over 25 years. We are fortunate that we’ve been able to build on the previous advances in the technology to have such a huge success with the SARS-CoV-2 vaccines now.

Won’t the vaccines change my dna?

Neither mRNA vaccines nor viral vector vaccines can change your DNA.

mRNA vaccines introduce mRNA molecules that code for a short segment of the spike protein into cells. This causes the body to produce the protein to which the immune system responds. the mRNA never enters the cell nucleus, so it cannot come into contact with your DNA. The average mRNA molecule lasts only about 10 hours before it is degraded.

Viral vector vaccines work in a similar way, except that DNA fragments coding for the spike protein are introduced into cells using a different virus (adenovirus) that has been engineered to be harmless to humans and unable to duplicate itself. The cell transcribes and then translates the DNA fragments into a small piece of the spike protein. This DNA also never enters the cell nucleus (adenoviruses, unlike retroviruses like HIV, do not have the machinery required to insert DNA sequences into the genome).