Illnesses Possibly Linked to Adenovirus Used in Trials

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Both vaccine candidate trials from Johnson & Johnson and AstraZeneca are halted due to safety concerns with illnesses in participants.  With both now on hold, they are looking into something called adenoviruses.  The CDC defines these as, “Common viruses that cause a range of illness. They can cause cold-like symptoms, fever, sore throat, bronchitis, pneumonia, diarrhea, and pink eye (conjunctivitis). You can get an adenovirus infection at any age.”

Sam Fazeli, a Bloomberg Intelligence analyst said, “While it could be a coincidence, there’s still the possibility that adenoviral vector vaccines run a higher risk of rare side effects — such as autoimmune attacks like transverse myelitis — than those of Pfizer-BioNTech, Moderna or Novavax.”

We have already established that pauses in vaccine trials due to illnesses and side effects are common, however Oxford says there isn’t enough evidence linking these illnesses to their vaccine, as such they resumed their testing weeks ago. AstraZeneca said they believe adenoviral vectors are good candidates for Covid vaccines, however the reactions to their earlier studies were similar to other failed vaccine trials that used adenoviruses.

That’s not to say they haven’t ever been successful in trials.  Earlier in the year a vaccine based on an adenovirus was approved to fight Ebola.  However, in 2008, a vaccine designed to prevent HIV that was made using an adenovirus was tied to increased infections.  So, this vaccine technology is hit or miss, to say the least. 

Johnson & Johnson says they are still learning about the illness of the participant of their trial.  According to Paul Stoffels, the company’s chief scientific officer, the “adenovirus in its experimental Covid shot has been used worldwide in more than 110,000 people.  We are building very quickly on a very large safety database of the carrier.”

The idea behind adenoviruses is drug delivery.  Some easily infect our cells easily, but only cause mild symptoms, and scientists have been able to switch genes within them.  Ron Crystal, a researcher at Weill Cornell Medicine in New York who pioneered the use of adenoviruses as vectors says, “You take out the genes that control the ability of the virus to proliferate, and put in your genes.”  When used in smaller amounts, the immune reaction to the adenovirus isn’t a significant issue according to him. “We didn’t realize how immunogenic these viruses were.  They’re essentially acting as an adjuvant, and that amplifies the immune response”

Lindsey Baden, an infectious disease specialist at Harvard-affiliated Brigham and Women’s Hospital says that the adenovirus like the one used in the Oxford Vaccine isn’t necessarily of high concern, but safety still is. “If you’ve studied it in 1,000 people, you don’t know a 1-in-10,000 risk; if you’ve studied it in 10,000 people you don’t know a 1 in 100,000, and so on.”  As the studies go on, they are still determining if the adenoviruses are associated with the side effects and illnesses that have appeared in these tests.  If they are, there will be setbacks with the development.

Be sure to check back with the ABN Blog regularly for Updates.

Sam Fazeli, a Bloomberg Intelligence analyst said, “While it could be a coincidence, there’s still the possibility that adenoviral vector vaccines run a higher risk of rare side effects — such as autoimmune attacks like transverse myelitis — than those of Pfizer-BioNTech, Moderna or Novavax.”

We have already established that pauses in vaccine trials due to illnesses and side effects are common, however Oxford says there isn’t enough evidence linking these illnesses to their vaccine, as such they resumed their testing weeks ago. AstraZeneca said they believe adenoviral vectors are good candidates for Covid vaccines, however the reactions to their earlier studies were similar to other failed vaccine trials that used adenoviruses.

That’s not to say they haven’t ever been successful in trials.  Earlier in the year a vaccine based on an adenovirus was approved to fight Ebola.  However, in 2008, a vaccine designed to prevent HIV that was made using an adenovirus was tied to increased infections.  So, this vaccine technology is hit or miss, to say the least. 

Johnson & Johnson says they are still learning about the illness of the participant of their trial.  According to Paul Stoffels, the company’s chief scientific officer, the “adenovirus in its experimental Covid shot has been used worldwide in more than 110,000 people.  We are building very quickly on a very large safety database of the carrier.”

The idea behind adenoviruses is drug delivery.  Some easily infect our cells easily, but only cause mild symptoms, and scientists have been able to switch genes within them.  Ron Crystal, a researcher at Weill Cornell Medicine in New York who pioneered the use of adenoviruses as vectors says, “You take out the genes that control the ability of the virus to proliferate, and put in your genes.”  When used in smaller amounts, the immune reaction to the adenovirus isn’t a significant issue according to him. “We didn’t realize how immunogenic these viruses were.  They’re essentially acting as an adjuvant, and that amplifies the immune response”

Lindsey Baden, an infectious disease specialist at Harvard-affiliated Brigham and Women’s Hospital says that the adenovirus like the one used in the Oxford Vaccine isn’t necessarily of high concern, but safety still is. “If you’ve studied it in 1,000 people, you don’t know a 1-in-10,000 risk; if you’ve studied it in 10,000 people you don’t know a 1 in 100,000, and so on.”  As the studies go on, they are still determining if the adenoviruses are associated with the side effects and illnesses that have appeared in these tests.  If they are, there will be setbacks with the development.

Be sure to check back with the ABN Blog regularly for Updates.

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