U nas zapłacisz kartą
Johnson & Johnson Krem do Twarzy - Odkryj Tajemnice Zdrowej i Promiennej Skóry
How does the vaccine work?
The Johnson & Johnson vaccine is what's known as an adenovirus vector vaccine. It uses an inactivated adenovirus, a type of virus that can cause the common cold, that has been engineered to carry the genetic code for the coronavirus's spike protein. The genetic instructions allow the body to build the spike protein, which the immune system learns to recognize. That way, if the real virus shows up, the immune system will already know how to defend itself.
The vaccine uses a modified adenovirus to enter cells and deliver the genetic code for the spike protein, but the viral vector itself is harmless.
"It's not a true virus — it has been modified so that you don't get infected," said the director of the stem cell program at the University of California, San Francisco, Dr. Arnold Kriegstein, a professor of neurology.
The vaccines made by Moderna and Pfizer-BioNTech use a different approach to teach the body how to build the coronavirus's spike protein. Both vaccines use synthetic messenger RNA, or mRNA, to deliver bits of genetic code to cells to trigger an immune response.
How It Works
Johnson & Johnson's vaccine is a single-dose adenovirus-based vaccine. It is a viral vector vaccine that uses a weakened live pathogen (adenovirus) as the delivery method (vector) for transporting a recombinant vaccine for COVID-19. The vaccine is also sometimes referred to as Ad26.COV2.S.
Recombinant vaccines use a small piece of genetic material from the virus to trigger an immune response. This genetic material for COVID-19 does not replicate in the body. A specific piece of the virus can be targeted, and recombinant vaccines are common and generally safe to use in a large population of people—even those with chronic health problems or who are immunocompromised.
There can be some drawbacks to recombinant vaccines. One example is that booster shots may be required over time. Examples of recombinant vaccines are pneumococcal vaccines and vaccines for meningococcal disease.
The science behind recombinant adenoviral vector vaccines has been around for a long time, but the only commercially available adenovirus-based vaccine is a rabies vaccine for animals. Adenovirus-based vaccines may also pose some problems in that the adenovirus is so common that the vaccine may not be as effective once booster doses are given, or that some people may already have immunity to the virus used in the vaccine.
What are the side effects?
The most common side effects reported in Johnson & Johnson's clinical trials are generally expected after any vaccination. They include pain at the injection site, redness of the skin, muscle pain, headache, fatigue, nausea and fever. While they may be uncomfortable, they actually signal that the immune system is responding to the vaccine.
Download the NBC News app for full coverage of the coronavirus outbreak
No serious or long-term side effects were reported during Johnson & Johnson's clinical trials, but the company is investigating two cases of severe allergic reactions that were reported later. Health care providers are advised to monitor people who have histories of allergic reactions for 30 minutes after vaccination and all other patients for 15 minutes.
According to the Centers for Disease Control and Prevention, rare cases of anaphylaxis, a life-threatening allergic reaction, occurred at a rate of 4.5 cases per 1 million doses administered of both the Moderna and the Pfizer-BioNTech vaccines.
Got Questions About Johnson & Johnson's COVID-19 Vaccine? We Have Answers
A medical worker at South Shore University Hospital gets ready to administer the newly available Johnson & Johnson COVID-19 vaccine in Bay Shore, N.Y., Wednesday. Clinical research found it to be 85% effective in preventing severe disease four weeks after vaccination, and it has demonstrated promising indications of protection against a couple of concerning variants of the coronavirus. Spencer Platt/Getty Images hide caption
A medical worker at South Shore University Hospital gets ready to administer the newly available Johnson & Johnson COVID-19 vaccine in Bay Shore, N.Y., Wednesday. Clinical research found it to be 85% effective in preventing severe disease four weeks after vaccination, and it has demonstrated promising indications of protection against a couple of concerning variants of the coronavirus.
Spencer Platt/Getty Images
That's welcome news in a country that still faces high levels of circulating virus in most regions, and a demand for vaccine that still far outstrips supply.
The J&J vaccine has some significant advantages, health officials say. Unlike the Moderna and Pfizer vaccines, it can be stored for up to three months at regular refrigerator temperatures, so it's easier to distribute to more places. And you're fully vaccinated after just one dose — a welcome convenience for many recipients who dread the two-shot regimen of the Moderna and Pfizer vaccines.
