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Third Dose of COVID-19 Vaccine Divides Opinion Among Scientific Community

Third Dose of COVID-19 Vaccine Divides Opinion Among Scientific Community

Should we or should we not have a COVID-19 booster? That's the dilemma. Public health experts have divided opinions on who should get it. Currently, only those who opted for the Pfizer vaccine are eligible for the third dose. 

To know the opinions of two great health professionals, Ethnic Media Services organized a session with the media to know the different points of view, and also the coincidences where better information can be provided to the public.

For Dr. Ben Neuman, virologist and head of the University of Texas Global Health Research Complex, humanity must focus on exterminating the SARS-CoV-2 virus, which causes COVID-19.

This, he said, because this disease, "will probably always kill a percentage of the people who are infected," because, looking at the figures worldwide, the case fatality rate, which is the number of people who die versus the number of confirmed infected people, always seems to settle at about 2.2 percent, with differences by age, "but one in 50 people who are infected with covid-19 are more likely to die. 

He added that, currently, there is no data to suggest that the virus will change to suit humanity, because "a percentage of people who are vaccinated and get COVID will also be hospitalized or die from COVID. And this will continue indefinitely.

The expert said that based on data from the Sept. 17 FDA meeting, it suggests that the term "fully vaccinated" is being used incorrectly. 

"No one is fully vaccinated. And, in fact, at this stage we don't really know what it would be like to be fully vaccinated. What we have is evidence of their waning immunity ?from vaccines? and their varying degrees ?of protection. 

In that regard, he noted that as time passes after vaccination, the amount of protection decreases to about 50 percent after five months, but the amount of protection against death remains constant at about 90 percent. 

"This is the dichotomy that is trapping people. The coronavirus is fundamentally a moving target, it's evolving, and it's changing. And if you look at the trajectory of change, the virus has gotten faster and better at reproducing very consistently throughout the outbreak, and based on the available data we don't have any evidence that this will be otherwise in the future," he said. 

And, he said, of all the variants of the disease that exist, currently 99 percent of infections in people are due to the Delta variant, which has more than 40 subtypes that are being monitored. 

"Delta is essentially synonymous with COVID-19 in the real world." However, the efficacy of Delta vaccines is about the same as with any other variant.

Neuman explained that while there is a relatively small difference between the elderly and those under 65 in terms of vaccine effectiveness, the benefit of a booster has also been found to be very large.

"Regardless of age group, with a booster, people end up with 5 to 10 times more antibodies than they had at the peak after the second vaccination, and they end up with up to 55 times more antibodies than they had just before the booster," he said.

"So the benefits seem to be universal. The consequences seem to be relatively similar across all age groups. And on that basis, it's hard for me, as a virologist, to understand the FDA's decision to recommend boosters only for a certain age group and not for everyone." 

"If vaccination is universal, universal boosters are going to be beneficial."

And is that, he recalled that vaccines such as hepatitis A or MMR are needed three or more doses to move towards a lasting immunity, while polio is virtually eradicated and smallpox completely eliminated due to widespread vaccination.

"So with additional doses of vaccine, we're essentially trying to move from what is considered reasonable protection to a position of certainty... And I think the benefit there is very, very great psychologically. And not just in terms of hope, but in the possibility of a better life, without COVID-19," he stressed.

The expert pointed out that the booster dose is exactly the same as those administered in the first and second shots.

However, in order for COVID-19 to be eradicated, it must not only be possible to vaccinate in the country, but globally, otherwise we will not be able to move towards the right path.

"You have to fight this the way you attack fire: put it out completely in one place and then extend the ring of protection until it covers everyone? If we don't stop this everywhere, it will eventually come back in some form." 

For her part, Dr. Monica Gandhi, a professor at the UC San Francisco School of Medicine, explained that unlike other viruses that have been eradicated in the world, COVID-19 or measles are infections that have animal hosts, and you can even catch them before you are sick. "So it doesn't have a short period of infection and we don't know if it's immune for life.

In that sense and unlike Dr. Neuman, Gandhi stressed that, unlike smallpox, "what will probably happen with COVID is that it will go the way of measles, so it will always be with us".

Thus, he said, this type of virus will become endemic, meaning it is a disease that always occurs in one population within one geographic area.

He recalled that in the United States alone there are three vaccines that help prevent deaths from the disease, and there are others around the world that can help mitigate the pandemic, which help produce T cells (antibodies).

What are T cells?

"T cells are really there to protect you from serious diseases." These are a kind of immune cell, whose main purpose is to identify and kill invading pathogens or infected cells. They do this by using proteins on their surface, which in turn can attach to proteins on the surface of these imposters.

Each T cell is highly specific. There are billions of possible variations of these surface proteins, and each one can recognize a different target and fight the virus like SARS-CoV-2 in a lasting way.

"It's pretty amazing what a two-dose vaccine does in terms of memory B and T cell storage."

"There is evidence from the SARS pandemic of 2000 to 2003 that people who survived still have very strong T-cell immunity; just as with measles vaccines. And vaccines also generate B cells that together with T cells create important antibodies," he added.

He explained that unvaccinated people are 20 times more likely to be hospitalized for the Delta variant than those who are vaccinated. So those who require a booster of the COVID-19 vaccine are those patients with compromised immune systems. "They always need three or more vaccines than a typical three-dose vaccination in a row."

Also, those over the age of 65 and those who are frequently exposed to the disease, such as health care workers.

For the pandemic to be contained, he said, all countries, especially low-income countries, must have access to vaccines safely and effectively, because so far only rich countries have the majority of the vaccine supply.

"The only way to prevent people from being exposed to the virus is to reduce transmission everywhere and keep everyone safe," because if that's not done, even Americans can't be safe as long as other people around the world are not vaccinated, agreed virologist Neuman.

You may be interested in: Merck Announces Oral Medication that Halves Hospitalization or Death from COVID-19

Pamela Cruz
Pamela Cruz
Editor-in-Chief of Peninsula 360 Press. A communicologist by profession, but a journalist and writer by conviction, with more than 10 years of media experience. Specialized in medical and scientific journalism at Harvard and winner of the International Visitors Leadership Program scholarship from the U.S. government.


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