As vaccines become available to help protect against COVID-19, PPMD is here to help you find answers to questions you might have about them. Please visit PPMD’s COVID-19 Information Center for additional resources and submit questions to firstname.lastname@example.org, so we can continue to adapt our resources to your concerns.
How the new adenovirus-based vaccine for COVID-19 is different
The FDA recently approved, under emergency use authorization, Janssen Pharmaceuticals – Johnson and Johnson’s new COVID-19 vaccine. The Janssen vaccine is the first adenovirus-based COVID-19 vaccine to be approved for use, which is different than the Pfizer and Moderna vaccines, which are mRNA-based.
Janssen’s COVID-19 vaccine uses a type of adenovirus, specifically adenovirus type 26 (Ad26), to deliver a piece of the DNA that is used to make the distinctive “spike” protein seen in SARS-CoV-2. Adenoviruses are relatively common and can cause a variety of mild illnesses in humans. However, Ad26, which typically causes the common cold and pink eye, is modified so that it cannot replicate nor cause illness, and instead transports the necessary genetic material into the body, prompting it to create the spike protein and generate an immune response against COVID-19.
It is important to differentiate between adenovirus, which is the vector used in the Janssen vaccine, and adeno-associated virus, which is used to delivery gene therapies in clinical trials for the treatment of Duchenne and other genetic conditions. While their names are similar, their molecular patterns (antigens) are distinct, so immunity to one type does not give immunity to another type.
Because of this key difference, the Janssen vaccine is safe for people with Duchenne to receive, including those who have received or hope to receive gene therapy.
However, if a vaccine were approved using an adeno-associated virus platform, it would be important for people wishing to receive gene therapy to avoid it.
Vaccines Currently Available for COVID-19
|Pfizer||Moderna||Janssen Biotech/Johnson and Johnson|
|Vaccine Platform||mRNA encased in lipid nanoparticles (fat bubbles) to keep it from degrading||mRNA encased in lipid nanoparticles (fat bubbles) to keep it from degrading||Recombinant, replication-incompetent human adenovirus type 26 vector|
|Age of Inclusion||12 years +||18 years +||18 years +|
|Accessibility||Storage between -94 degrees Fahrenheit (institutional research freezers), stable x5 days after thaw||-4 degrees Fahrenheit (regular freezer), stable x30 days after thaw and at room temperature for 12 hours||36 degrees Fahrenheit to 46 degrees Fahrenheit (regular refrigerator); or 47 degrees Fahrenheit to 77 degrees Fahrenheit (room temperature) for up to 12 hours|
|Dosing Schedule||2 injections given 3 weeks apart||2 injections given 28 days apart||Single dose|
|Efficacy||95% effective||95% effective||85% effective in preventing severe/critical COVID-19 occurring at least 28 days after vaccination, 100% effective in preventing death|
|Possible Side Effects||Pain at injection site, fatigue, mild fever, headache, muscle pain, joint pain, fever; younger adults have reported more side effects than older adults||Pain at injection site, fatigue, mild fever, headache, muscle pain, joint pain, fever; younger adults have reported more side effects than older adults||Pain at the injection site, headache, fatigue, muscle aches and nausea|
|Need for future booster shots||Unknown||Unknown||Unknown|
* Table reflects COVID-19 vaccines that have received emergency use authorization from the US Food and Drug Administration (FDA) as of March 5, 2021.
Vaccines Not Yet Approved
- The AstraZeneca vaccine, which is NOT yet approved, uses a viral vector (adenovirus) that carries the genetic instructions from the virus’s DNA to the cells of the body to make a limited supply of the full COVID-19 spike protein. The body then sees the foreign spike protein and develops its own antibody to this foreign visitor. This vaccine is being studied in both one and two injection dosing schedules. A similar vaccine from a Russian company (Sputnik V) is also earlier in its development.
- Novavax, Sanofi, and GlaxoSmithKline vaccines, also NOT yet approved. Novavax uses “virus-like” particles that are housed in a viral vector (baculovirus). These genetically engineered virus-like nanoparticles are injected into the body, are seen as foreign and mount an immune response. Sanofi and GlaxoSmithKline are similar, but include a protein subunit from the COVID-19 spike protein that is injected and mounts an immune response.
- Sinovac and Sinopharm vaccines, also NOT yet approved, are planning to inject whole, inactivated or “killed” virus into the body that will mount an immune response. This is similar to the inactivated vaccines that we give to children, as well as the influenza vaccine.
Staying Safe & Making Informed Decisions
There are, of course, many things we do not yet understand about the vaccines currently authorized (i.e., how long does immunity last, will vaccines need to be boosted, etc.). While we are answering these questions, it is important to keep doing all the things we have been doing to keep ourselves and each other safe – social distance, wear your mask, wash your hands, stay home if you are sick.
As more vaccines are authorized, PPMD will continue to share updated information. Please let us know if you have any questions. Being informed and talking with your healthcare provider is the best way to make any decision.