One-Shot Wonder: The Janssen Vaccine

March 20th, 2021. By Cayden Tu '24

Despite what seems like a never-ending pandemic, advances in medical technology and health industry research are providing hope for the future. New vaccines have been approved by the FDA and one sign of hope is the Janssen vaccine created by the Johnson & Johnson pharmaceutical company. The vaccines thus far approved by the U.S. Congress pose the potential to turn this pandemic around, however, the Janssen vaccine is different from all the others. Instead of having to endure the side effects of two vaccine inoculations, the Janssen vaccine only requires one.

After grueling months of testing, scientists have found that this Janssen vaccine is just as effective as any other two-dose vaccine, with an 85% efficacy rate in preventing serious disease across all regions studied. Like the other COVID-19 vaccines developed so far, this vaccine has the COVID-19 virus with proteins attached to it that enter human cells. However, this is where the similarities end. Instead of containing the spike protein’s instructions in a single-stranded RNA, this Janssen vaccine uses double-stranded DNA. Even though this difference seems like a small detail, if you think back to your high school biology class, you’ll recall that RNA and DNA are very different. RNA contains ribose with only one nucleic acid strand while DNA contains deoxyribose as a duplicated strand.

Adding to their differences, the Janssen vaccine is adenovirus-based, which means that the gene for this coronavirus spike protein is added to the adenovirus (specifically Adenovirus 26). Adenovirus has a few advantages compared to the typical RNA strand used by both the Pfizer and Moderna vaccines. This Adenovirus 26 located in the Janssen vaccine is more rugged than the other vaccines for its DNA-built strand. Furthermore, this vaccine’s tough coat of protein makes it able to be kept refrigerated for up to an outstanding three months.

As all methods to stop a rapid-growing pandemic have extensive processes for successful execution, this Janssen vaccine has a similar process to the other vaccines. Once a person’s arm is injected by the vaccine, the Adenovirus 26 becomes engulfed by arm cells and travels to the nucleus of the cell-- the place where the essential DNA is stored. After the adenovirus’s biological sequence is read by the cell’s molecules, the DNA starts creating copies of the spike proteins after the mRNA from the vaccine leaves the cell. By releasing the adenovirus into the body, the immune system immediately tells the body of this potential danger so the immune system can react much more strongly to future COVID-19 spike proteins.

Inevitably, a vaccinated cell will die and because of this, spike proteins with fragments of protein from COVID-19 are taken by cells that have the sole purpose of presenting antigens. Further, immune cells might lock onto these spike proteins and now these immune cells have the capability to create antibodies that can attach to these exact spike proteins of COVID-19. Finally, the immune system is alerted and antibodies against COVID-19 are both created so these antibodies can work perfectly, marking future viruses for demolition and preventing any infection.

Overall, this Janssen vaccine is an important addition to our world’s arsenal of weapons to fight against a pandemic that has created so much chaos already, bringing hope during a difficult time.