By Alexandra Becker
On Feb. 27, the U.S. Food and Drug Administration (FDA) issued an Emergency Use Authorization to a third COVID-19 vaccine. Manufactured by Janssen Biotech Inc., a pharmaceutical company owned by Johnson & Johnson, this new COVID-19 vaccine varies substantially from those created by Pfizer and Moderna, with notable differences in its technology and its efficacy (but we will dive deeper into what that means). Below, we address the top five questions surrounding the latest COVID-19 vaccine.
The Johnson & Johnson COVID-19 vaccine is a viral vector vaccine, whereas the Pfizer and Moderna vaccines are mRNA vaccines.
Vaccines work by teaching our cells to make a protein that triggers an immune response. That immune response in turn produces antibodies, which fight viruses. The mRNA COVID-19 vaccines, which include those created by Pfizer and Moderna, instruct our cells to make something called a “spike protein,” which is found on the surface of the SARS-CoV-2 virus (the virus which causes COVID-19 disease). After a person receives the COVID-19 vaccine and this harmless spike protein is created, our immune system begins to produce antibodies to fight the spike protein. This trains our bodies how to fight the spike protein so that if we are exposed to the SARS-CoV-2 virus in the future, our bodies will already know how to attack it before we become sick with COVID-19 disease.
The new Johnson & Johnson vaccine uses a viral vector technology to achieve this same response. According to the Centers for Disease Control and Prevention (CDC), viral vector vaccines work through the use of a modified version of a completely different and harmless virus derived from the common cold (known as the vector) to deliver important instructions to our cells—in this case, the instruction to make this spike protein. This harmless virus will enter our body, provide our cells with the blueprint to produce the spike protein that is found on the surface of the SARS-CoV-2 virus, and trigger an immune response in our body—just like the mRNA vaccines. Notably, because this vaccine does not use the SARS-CoV-2 virus (and instead uses a harmless vector), you cannot get COVID-19 from the vaccine.
Scientists have been researching viral vector technology since the 1970s and have studied their safety and efficacy against diseases such as Ebola, Zika, HIV and influenza (the flu).
The Johnson & Johnson vaccine requires one shot instead of two.
Unlike the Pfizer and Moderna mRNA vaccines, which require two shots given weeks apart, this new vaccine only requires one shot—a notable benefit in regards to vaccine supply and access, with each person needing just one shot administered, instead of two.
Like the others, it is administered in the muscle in the upper arm, and the side effects observed during clinical trials were similar as well: pain, redness or swelling at the injection site, as well as tiredness, headaches, muscle pain, chills, fever and nausea. In the clinical trials, the side effects were most common within 7 days of getting the vaccine, and they were also more commonly observed in people 18 to 59 years of age. As with the Pfizer and Moderna vaccines, it also take a few weeks after the shot to gain the full benefits of the vaccination.
In clinical trials, it was shown to be slightly less effective than the Pfizer and Moderna vaccines.
In U.S. trials, the Johnson & Johnson vaccine was shown to be 72 percent effective in preventing moderate COVID-19 infections, and in all trials, it was shown to be 85 percent effective in preventing severe illness and hospitalization. In these trials, not a single participant who received the Johnson & Johnson vaccine and later contracted COVID-19 became sick enough to require hospitalization—in other words, it was essentially 100 percent effective in preventing death or hospitalization.
While the Pfizer and Moderna vaccines were shown to be 95 percent and 94 percent effective in clinical trials, they were also studied prior to the new COVID-19 variants, which may explain some of the discrepancy.
The Johnson & Johnson vaccine does not contain fetal tissue or stem cells.
The Johnson & Johnson vaccine does not contain any stem cells or fetal cells. However, there has been some controversy about its development, which did include the use of an engineered cell line that dates back to an aborted fetus from 1985 in the Netherlands. The cells used in the development of Johnson & Johnson’s COVID-19 vaccine were grown in a laboratory and are thousands of generations removed from the original fetal cells. This historic fetal cell line is commonly used in medical research and enables the rapid production of hundreds of millions of doses of viral vector vaccines. No new fetal tissue will ever be necessary in the production of the Johnson & Johnson COVID-19 vaccine.
The Johnson & Johnson vaccine is easier to ship and store.
This latest vaccine has less rigid storage requirements than the Pfizer and Moderna vaccines, primarily because the viral vector technology is far more stable than mRNA from a scientific standpoint. While the Pfizer and Moderna vials must be kept below a certain temperature to maintain the integrity and efficacy of the vaccine, the Johnson & Johnson vaccine can be stored for up to three months at the temperature of a regular refrigerator. That means it can essentially be shipped and stored anywhere, which is good news for expanding access to the vaccine, especially when it comes to rural areas or communities without ultra-cold pharmacy-grade freezers.
The most important thing to know is that medical experts consider all three vaccines safe and highly effective in combating COVID-19, and they strongly encourage everyone to get their vaccine when it is their turn, no matter which manufacturer it was developed by.