The Johnson & Johnson COVID-19 vaccine has been approved for emergency use in the U.S., and millions of doses are now being shipped. We already have mass immunizations underway with the Pfizer and Moderna vaccines, which look better and better as we keep getting new reports of their benefits and minimal side effects. Widespread distribution of the J&J vaccine should speed up our progress toward herd immunity to end this pandemic.
Different Types of Vaccines
Before COVID-19, vaccines were typically made by using either dead viruses, live inactivated viruses or parts of viruses. The Pfizer and Moderna vaccines are different from traditional vaccines because they contain lab-manufactured copies of human genetic material called messenger RNA (mRNA) that teaches your immune system to destroy the spike protein of the COVID-19 virus. The spike protein is the “key” that allows this virus to enter human cells, so if you are exposed to the virus that causes COVID-19, your immune system keeps you from being infected.
The J&J vaccine differs from the Pfizer and Moderna vaccines because it uses a harmless adenovirus that has not been shown to cause human disease, instead of mRNA. The J&J vaccine developers attached the spike protein of the virus that causes COVID-19 to the harmless adenovirus. When this vaccine is injected into you, your immune system learns to recognize and destroy the spike protein. Without the spike protein, the invading virus cannot get into your cells, so it will quickly disintegrate and you will not be infected with COVID-19.
• The adenovirus used in the J&J vaccine has been repeatedly shown to be safe; it does not cause human disease (Molecular Therapy, Nov 4, 2020;28(11):2303-2304).
• The spike protein attached to the adenovirus in the vaccine causes humans to develop very high levels of antibodies that destroy the spike protein and help to prevent COVID-19.
• Usually only one injection will cause very high protective levels of antibodies.
• Adenovirus-based vaccines are very stable, so they do not have to be stored at very low temperatures that are required for the Pfizer and Moderna vaccines.
More Vaccines On the Way
Another vaccine that is expected to be approved soon, the Oxford/AstraZeneca vaccine, uses the same principle as the J&J vaccine. It is made with a modified chimpanzee adenovirus. Trials of a fifth vaccine, from Novavax, show that it is safe and effective, and approval of this vaccine is also expected soon.
Which vaccine should you try to get? I recommend that you take any vaccine you can get as soon as possible. All three of the approved vaccines have good safety and effectiveness records. In addition to protecting yourself and your loved ones, you will be doing a service to your fellow humans, since this COVID-19 pandemic will not end until about 85 percent of the population become immune. This will require a large percentage of the population to receive vaccines.