Interview With Edward E. Walsh, MD: Vaccinating Older and At-Risk Adults Against Respiratory Syncytial Virus

Although RSV has been well recognized for many years as a pediatric problem—since the late 1950s, in fact—it really has been over the last 30 years that there has been increasing prevalence or knowledge of RSV in adult populations.

Underlying medical conditions as well as advancing age, clearly are risk factors for getting into trouble with this virus.

So, over the last year (roughly), 3 vaccines have been approved for use in adult populations.

These vaccines are interesting in that they all are based on the same antigen, that is the prefusion F protein or fusion protein of RSV.

All 3 vaccines give relatively similar efficacy. You could look at…the syndromes that we're protected against and you'll see different numbers….The vaccines all blocked about 60% of any RSV respiratory symptom. That is, minor sniffles or sore throat. But when you looked at more severe symptoms—such as shortness of breath, a cough that was troublesome, sputum production, wheezing, the kinds of things that really make someone ill—there the vaccines were closer to the mid 80% effective.

As far as the safety through these trials, they're all very safe in terms of their immediate side effects. They do differ somewhat, and again this has to do with the way these vaccines are composed, although they all induce antibody to the prefusion F. As most of us know, the mRNA vaccines do tend to have a little bit of a kick with them. We learned this with the COVID[-19] vaccines, that they tend to have a slightly higher incidents, say of a sore arm and some fever and maybe some chills. Generally short lived. Usually for 24 hours or less.

The GSK vaccine has the same adjuvant included in it that is in the shingles vaccine, the highly effective shingles vaccine. The dose of this adjuvant is only half of what's in the shingles vaccine. It probably accounts for why you see a slight increase in sore arm and…achiness that occurs with the GSK vaccine compared to the Pfizer vaccine, which does not have this adjuvant.

The GSK vaccine requested that this be considered to vaccinate people between the ages of 50 and 59 who have a high risk condition. I think this was something we, I wouldn't say expected to see, but we were really very hopeful we would see this, and I think we also are hopeful we'll see this with the other vaccines, you know, the other 2 RSV vaccines as well. And in fact, I wouldn't even stop at 50…I mean, we certainly have seen people as young as 28 who have very bad lung disease end up in the hospital with RSV. Now,…physicians always have the option of…off-label use of vaccines, and I think there certainly might be situations where such younger people might very well benefit from a vaccine, an RSV vaccine.

From a practical point of view, especially in adult populations, the ability to give multiple vaccines simultaneously is very helpful because, let's face it, we don't go to the doctor all the time, like little babies who show up every couple of weeks or every couple of months. So from a practical point of view, all of these vaccines have been tested with flu vaccine given concurrently, and they're considered safe. And they don't interfere with each other in any kind of significant way. And so, therefore, giving them simultaneously can be done.

The most important information that we're going to be seeing over the next year or so is going to be, in the real world, how effective these [vaccines are]; you know, their true effectiveness….That will tell us a lot about how cost effective and how worthwhile it is to expend the time[,] effort, [and] money to vaccinate against RSV. And I think that that's going to be very important information, and it's being collected now….Keeping track of that is very, very important.

For other articles and videos in this AJMC® Perspectives publication, please visit "Vaccinating Older and At-Risk Adults Against Respiratory Syncytial Virus"