Dr. Petri: Get ‘Revolutionary’ New Vaccines Against COVID-19 and RSV

September 19, 2023
Vaccine booster graphic

(Illustration by Emily Faith Morgan)

Saturday is the first day of fall and University of Virginia infectious diseases expert Dr. William Petri says it’s a great time to think about getting the “revolutionary” new vaccines to protect against the evolving COVID-19 virus and respiratory syncytial virus, or RSV.

He recommends getting vaccinated against the flu, too.

UVA Today reached out to Petri to learn who should get what vaccine and when.

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Q. The Food and Drug Administration recently approved the new COVID-19 vaccines. What does the Centers for Disease Control and Prevention recommended?

A. The fall booster for COVID-19 is recommended for everyone 6 months and older. I, in fact, have recommended to my oldest son that his daughters – my granddaughters – who are 1 and 3 years of age, receive it. This is not only to prevent my granddaughters from being ill with COVID-19 and missing preschool, but also because children that age are at risk of severe disease and even death. I think we all agree that no child should die of a vaccine-preventable illness.

Q. When should people 65 and older and pregnant women get vaccinated?

A. The most urgent group to vaccinate right now is adults who are 65 years of age and older and pregnant women. These two groups are at greatest risk of severe COVID-19 hospitalization. In fact, the vast majority of hospitalizations and deaths in the United States today are those who are 65 to 75 years of age and older.

Pregnancy increases the risk of severe COVID-19 about twofold and appears to also have a small but significant increase in the risk of preterm birth, so that’s the reason for pregnant women to be vaccinated with this new fall booster sooner rather than later. If you’ve had COVID-19 recently the CDC recommends that you wait at least three months before receiving this fall booster. The reason for that is that you have relatively high levels of immunity immediately after a new infection.

Q. What do you know about the new booster?

A. It’s very good news that the FDA has approved, and the CDC is now recommending, a new booster that is being made by both Moderna and Pfizer that is much better at combating the newest variants of the COVID-19 virus.

The vaccine was made against the variant that was most common July 1, so you might wonder “Well, is it really going to be any better than the booster that we all hopefully just received?”  The good news is that studies so far are showing that the new COVID-19 vaccine is making antibodies that are 10 times better not only at getting that old variant from this summer, but also these newest variants that we’re experiencing right now.

Q. How prevalent is COVID-19 right now and why there is a spike?

A. There are a few reasons that this is happening right now. Number one, the virus is continuing to evolve and mutate to evade the immunity that we got from the previous vaccines and from prior infections with COVID-19. A new variant called EG.5 replaced XBB.1.5 as the most common variant over the summer.

Second, we understand now that immunity against COVID-19, whether it’s immunity from the vaccine or from infection, begins to diminish or wane one to four months later.

Finally, I think the other thing that may be contributing to this increase is that with the heat wave we’ve had this summer, people might be spending more time indoors where the virus is spread more readily than outdoors.

Q. Why are people who got the previous booster getting sick anyway?

A. The short answer is of course that the booster is not 100% effective. The old “bivalent” booster, of which 153 million doses have been given, has been shown to be 60% to 70% effective at preventing severe omicron. The effectiveness of the booster is greatest in the month after you get it and then starts to wane, but this is still quite substantial protection on top of the protection that we already had from the original vaccine.

Dr. William Petri
Dr. William Petri is, among many other things, the Wade Hampton Frost Professor of Medicine, and a professor of microbiology and immunology; and an infectious diseases expert. He is also a “double Hoo.” (Photo by Dan Addison, University Communications)

The COVID-19 vaccines are revolutionary and have saved millions of lives, literally. They’re based on an important discovery which was not so much the mRNA part of the vaccine, but the fact that we as scientists learned that the best way to vaccinate against these viruses is to freeze the spike protein in the shape or the conformation at which it binds to human cells. This is known as the prefusion conformation.

That’s what the COVID vaccines do, and that’s what the new RSV, or respiratory syncytial virus, vaccine does. This allows for a much more effective antibody response that prevents the virus from binding to our cells and causing an infection.

Q. Who should get the flu vaccination?

A. This year’s flu vaccine has been modified to give you better protection. Your readers may not remember, but in 2009 influenza H1N1 caused a pandemic in the world. That’s because this virus has the ability to swap genes with influenza viruses from pigs and birds, and that’s what happened in 2009.

We haven’t seen that dramatic of a change in H1N1 this year, but it does continue to evolve, so this new flu vaccine is recommended for everyone 6 months of age and older.

And again, I’ve asked my son to have his daughters vaccinated with this. Young infants and children and the elderly are the ones who are at greatest risk of dying from flu. But boy, if you’ve had flu recently, you don’t want to have it again. This is an infection that’s going to lay you pretty low for a few days – and then you’re going to have a really annoying cough and fatigue for days to weeks later. So, go ahead and get that vaccine.

It’s easy to remember: COVID and flu, age 6 months and older, and you can get them both at the same time.

Q. Who should get the new vaccine against RSV?

A. There’s really good news about respiratory syncytial virus, or RSV, this year. There’s both a vaccine for the elderly and there is a new, monoclonal antibody to prevent the first RSV infection in children 8 months of age and younger.

This is really revolutionary, as the elderly are at great risk of RSV. In fact, my mother died of RSV infection a few years back when there was not a vaccine.

Everyone who is 60 years of age and older should receive the RSV vaccine. The other risk group for severe RSV is young children, especially with their very first RSV infection.

What is new is that there is a monoclonal antibody that this summer has been FDA-approved and CDC-recommended for children 8 months of age and younger. It’s 75% effective at preventing that first RSV infection that can be so severe.

Q. How do you suggest people pace getting the vaccines?

A. So, this is a lot all at once. Just remember that if you are 60 years of age and older, there’s three vaccines, and you can get them all at the same time this fall: flu, RSV and COVID-19.

For everyone else who’s 6 months of age and older, there’s two vaccines, COVID-19 and flu, and for parents of children who are 8 months of age and younger, do go to your health care provider and get this new monoclonal antibody that will prevent the first RSV infection that can be so severe in children.

All in all, this is a really great fall for vaccines to prevent this triple threat of respiratory viruses.

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Jane Kelly

University News Senior Associate Office of University Communications