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A panel of infectious disease experts shared their take Wednesday on the importance of the newly approved bivalent COVID-19 vaccines, why authorization without human data is not for them a cause for alarm, and what they are most optimistic about at this stage of the pandemic.
"I'm very encouraged by this new development," Kathryn M. Edwards, MD, said during a media briefing sponsored by the Infectious Diseases Society of America (IDSA).
It makes sense to develop a vaccine that targets both the original SARS-CoV-2 strain and Omicron BA.4 and BA.5, she said. "It does seem that if you have a circulating strain BA.4 and BA.5, hitting it with the appropriate vaccine targeted for that is most immunogenic, certainly. We will hopefully see that in terms of effectiveness."
Changing the vaccines at this point is appropriate, Walter A. Orenstein, MD, said. "One of our challenges is that this virus mutates. Our immune response is focused on an area of the virus that can change and be evaded," said Orenstein, professor and associate director of the Emory Vaccine Center at Emory University in Atlanta.
"This is different than measles or polio," he said. "But for influenza and now with SARS-CoV-2...we have to update our vaccines, because the virus changes."
Man vs Mouse
Edwards addressed the controversy over a lack of human data specific to these next-generation Pfizer/BioNTech and Moderna vaccines. "I do not want people to be unhappy or worried that the bivalent vaccine will act in a different way than the ones that we have been administering for the past 2 years."
The US Food and Drug Administration emergency use authorization may have relied primarily on animal studies, she said, but mice given a vaccine specific to BA.4 and BA.5 "have a much more robust immune response" compared to those given a BA.1 vaccine.
Also, "over and over and over again we have seen with these SARS-CoV-2 vaccines that the mouse responses mirror the human responses," said Edwards, scientific director of the Vanderbilt Vaccine Research Program at Vanderbilt University in Nashville and an IDSA fellow.
"Human data will be coming very soon to look at the immunogenicity," she said.
A "Glass Half Full" Perspective
When asked what they are most optimistic about at this point in the COVID-19 pandemic, Orenstein said, "I'm really positive in the sense that the vaccines we have are already very effective against severe disease, death, and hospitalization. I feel really good about that. And we have great tools.
"The bottom line for me is, I want to get it myself," he said regarding the bivalent vaccine.
"There are a lot of things to be happy with," Edwards said. "I'm kind of a glass-half-full kind of person."
Edwards is confident that the surveillance systems now in place can accurately detect major changes in the virus, including new variants. She is also optimistic about the mRNA technology that allows rapid updates to COVID-19 vaccines.
Furthermore, "I'm happy that we're beginning to open up ― that we can go do different things that we have done in the past and feel much more comfortable," she said.
More Motivational Messaging Needed
Now is also a good time to renew efforts to get people vaccinated.
"We invested a lot into developing these vaccines, but I think we also need to invest in what I call 'implementation science research,' " Orenstein said, the goal being to convince people to get vaccinated.
He pointed out that it's vaccinations, not vaccines, that saves lives. "Vaccine doses that remain in the vial are 0% effective.
"When I was director of the United States' immunization program at the CDC," Orenstein said, "my director of communications used to say that you need the right message delivered by the right messenger through the right communications channel."
Edwards agreed that listening to people's concerns and respecting their questions are important. "We also need to make sure that we use the proper messenger, just as Walt said. Maybe the proper messenger isn't an old gray-haired lady," she said, referring to herself, "but it's someone that lives in your community or is your primary care doctor who has taken care of you or your children for many years."
Research on how to better motivate people to get vaccinated is warranted, Edwards said, as well as on "how to make sure that this is really a medical issue and not a political issue. That's been a really big problem."
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Cite this: Why Some Infectious Disease Docs Are 'Encouraged' by New Bivalent COVID Vaccines - Medscape - Sep 07, 2022.