An increasing amount of evidence suggests that the Covid-19 vaccine may slow down the spread of the coronavirus, Dr. Anthony Fauci said Wednesday.
Whether the vaccine can prevent the transmission of the virus is a “threatening question,” Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a coronavirus response team in the White House. “If someone becomes infected despite the vaccination – we call it a ‘breakthrough’ infection, does that person have the ability to transmit it to another person?”
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“There have been some studies that point in a very favorable direction,” he said, adding that these studies need to be confirmed by supplementary research.
Fauci highlighted two recent studies that looked at someone’s viral load – that is, how much virus he or she has in the body – and transmissibility.
One study from Spain, published February 2 in The Lancet, found a direct link between viral load and transmissibility. The higher the virus load, the greater the transmissibility of the virus.
This is consistent with years of research on HIV: there is a direct link between the virus load in someone’s blood and the likelihood that individuals will transmit HIV to a sexual partner, Fauci said.
For SARS-CoV-2, the virus that causes Covid-19, researchers focus on how much virus occurs in the nasopharynx, the upper part of the throat behind the nose that is reached with a long, lean swab.
The second study described by Fauci – a paper that did not undergo a peer review, which was posted on preprint server medRvix last week – looked at coronavirus infections in Israel, a country with very high vaccination rates.
This article found that individuals infected after receiving their first dose of Pfizer-BioNTech vaccination had a “significantly reduced” viral load compared to non-vaccinated individuals.
This is another example of ‘scientific data that suggests that [the vaccine] “has very important implications from the point of view of public health for interfering with and reducing the dynamics of the outbreak,” Fauci said.
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Dr. John Anthony Vanchiere, head of infectious diseases in children at Ochsner LSU Health Shreveport in Louisiana, said the two studies “go hand in hand nicely.”
‘We know that it is the case for flu and other respiratory viruses that higher virus load is associated with increased transmission,’ is the fact that the vaccine reduces the virus load, even shortly after you receive your first dose, it is very important to have data . “
Both Pfizer-BioNTech and Moderna are currently investigating how the vaccine affects transmissibility, Fauci said.
“The bottom line,” he said, “is that if it’s your turn to be vaccinated, then it should be vaccinated. It’s not only good for you and your family and community, it’s going to have a very important impact on the dynamics of the outbreak in our country. “
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Akshay Syal contributed.