- There are now three different COVID-19 vaccines authorized for use in the USA.
- Two are based on mRNA (Pfizer, Moderna), while one is an adenovirus (Johnson & Johnson).
- Dr. Fauci explained how they differ in action, but said that “the ultimate final game” is the same.
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The United States now has three vaccines authorized to fight the pandemic: two mRNA options from Pfizer and Moderna and an adenovirus injection from Johnson & Johnson.
While it is true that the injections of Moderna and Pfizer were generally more effective than J&J in their trials, the experts emphasized that all of these vaccines share two very important statistics in common: zero hospitalizations and zero deaths among trial participants fully vaccinated.
And when asked which injection can provide people with the best long-term protection against infections, including protection against new variants of worrying viruses like B.1.351, leading to virus expert Florian Krammer told Insider on Monday:
“There is little that can be said, for now.”
But, we already know that there are important differences in the way these two types of vaccines work.
During a COVID-19 briefing at the White House on Monday, President Biden’s Chief Medical Adviser, Dr. Anthony Fauci, revealed exactly how each injection works.
Images from Pfizer and Moderna provide genetic instruction manuals to the body to learn how to fight coronavirus safely
Pfizer mRNA-based COVID-19 vaccine.
Pete Bannan / MediaNews Group / Daily local news via Getty Images
Pfizer and Moderna vaccines train the body to learn how to fight COVID-19 by injecting mRNA (messenger RNA) into a person’s deltoid – the round muscle that surrounds the arm and shoulder.
“The mRNA that is injected into the muscle encodes the peak protein,” explained Fauci on Monday.
The peak protein in coronavirus is what would otherwise allow the virus to cling and invade our cells. But mRNA vaccines train our bodies to say immunologically, “not so fast.“
“The body sees this [protein] and makes an immune response against it, giving the protection that has been demonstrated with both mRNA vaccines, “added Fauci.
J&J inserts a harmless cold virus to do the same job
The first boxes of the Johnson & Johnson Covid-19 vaccine are loaded into a box for shipment at McKesson’s facilities in Shepherdsville, Kentucky, on March 1, 2021.
Timothy Easley / AFP via Getty Images
The J&J injection, in contrast, injects viral DNA (not mRNA) into a person’s arm. This is one of the main reasons why the J&J vaccine is much easier to manufacture and store in the refrigerator: the internal DNA is not as fragile as the single-stranded mRNA of the Pfizer and Moderna vaccines.
J&J’s DNA is encapsulated within a “competent, harmless and non-replicating virus,” said Fauci.
The virus in question, called Adeno26, is a common cold virus that has had its disease-causing genes removed, so it cannot make you sick.
As soon as the vaccine is injected into a person’s arm, the virus injects its DNA into cells. There, they are copied into messenger RNA. This mRNA then encodes peak coronavirus proteins in the same way that Pfizer or Moderna injections would.
Both types of vaccines result in the same ‘final game’ for the virus
Dr. Anthony Fauci in Washington DC on February 25, 2021.
Saul Loeb / AFP via Getty Images
Therefore, “the ultimate final game” of COVID-19 adenovirus and mRNA vaccines is the same, said Fauci.
“Both vaccines result in a protein spike in the correct conformation that gives the body the opportunity to feel that this is the real virus it is seeing.”
To be clear, “it is not [the virus], is the protein “, said Fauci.
This prepares the body of a vaccinated person to fight any eventual COVID-19 infection if the vaccinated person comes into contact with the virus again.
The good news is that both mRNA and adenovirus vaccines seem to fight very well against the most serious infections of COVID-19: the 2-dose courses from Pfizer and Moderna were more than 94% effective in their trials, while the J&J was 85 % effective against serious illness, disease and death.
There is also speculation that adenovirus vaccines like J&J may give people a broader and more robust form of immunity against viral variants, both with a demonstrated antibody and with a T cell response (mRNA vaccines may provide only closer protection) antibodies.) But that remains to be seen, as more people are vaccinated and variants of the virus continue to spread.
In any case, experts agree that all three authorized vaccines need to work together in order to contain the spread of the virus in the United States and help end the pandemic.