Barbecues, Sunshine and COVID-19: Updated Vaccines Get Nod Amid Summer Surge

What are some of the reasons SARS-CoV-2 keeps popping up in the summer, unlike the flu, which tends to be more winter seasonal?

Coronaviruses are just inherently different than influenza, and immunity to coronaviruses doesn’t last that long. That’s why people will get the common cold again and again. The virus has ways of evading immunity, and I think that’s what we’re seeing. We’re seeing lots of mutations that allow the virus to become more contagious.

Also, immunity wanes pretty quickly. We think that vaccination is most effective for about four months. It reaches its peak after about four weeks. And natural infection can be a little bit longer, but it’s not like with some other viruses (e.g., chicken pox or measles), which provide lifelong immunity after a natural infection. That being said, I don’t see us recommending more than one vaccination dose a year to people who have previously been vaccinated and are otherwise average risk.

The good news is, as you said, cases are becoming less severe, correct?

That’s right. It appears that even though we are getting a surge now, it seems like it’s less severe, and that’s probably because we have immunity here. That herd immunity is going to keep developing over the course of time. Of course it’s accelerated by people getting vaccinated.

Uptake of the COVID vaccine is low, with less than a quarter of the population getting the 2023-2024 updated version. We know vaccination prevents severe illness and helps protect the more vulnerable people in the population. What other reasons do you give patients when recommending vaccination?

You’re right, protecting others and protecting the community is important. If we are able to lessen the amount of transmission in our community, we are going to keep people out of the hospital and protect our most vulnerable.

The other reason that’s become very clear over the past year, with multiple studies published, is that vaccination clearly protects against Long COVID.

There was a study published early this summer that showed that the incidence of Long COVID was highest in the original strain and has declined over the life of the pandemic, and both in people who are vaccinated and unvaccinated. But repeated infection appears to be a risk factor for Long COVID. There’s still a lot of concern out there about Long COVID, and to me, that’s a very compelling reason to get vaccinated, especially if you are in a group that is more susceptible to Long COVID.

How do vaccines protect against Long COVID, beyond preventing COVID infection in the first place?

The reasons for decreased risk of Long COVID with vaccination are probably multifactorial. So of course the obvious, if you’re not getting infected with COVID, you can’t be at risk of Long COVID. But I think, too, we know the vaccination prevents severe disease, and severe disease is a risk factor for Long COVID in and of itself, so I think that’s a big reason.

There’s a lot of talk about inflammation and how harmful that is, so anything you are doing across the board to lessen inflammation (such as decreasing severity of a COVID infection with vaccination) is presumably going to be better for you down the line.

What can you tell us about the upcoming combination flu/COVID vaccine as far as effectiveness and arrival?

I think they are shooting for fall of next year. And that’s going to be a real game-changer, actually.

I think it’s going to overcome some of the vaccine hesitancy that we’re seeing with COVID. People are used to getting their yearly flu shot, and if you don’t have to face two injections or go to different places to find the vaccines, getting the COVID vaccine will be easier. We know that eliminating any barrier is helpful to uptake.

There’s some suggestion that getting the influenza and COVID vaccines at the same time can enhance immunity to both viruses – and manufacturers of the combined shot have said early data suggest the same is true with the dual vaccine. What can you tell us about that and whether we should brave both shots at once this fall, if both are ready?

It’s safe to get them both at the same time. And small studies have demonstrated more immunogenicity when getting flu and COVID vaccines at the same time, though the mechanism is unclear. It has been postulated that additional immune activation from two vaccines may lead to a more robust immune response, which makes sense.

It is also not clear why the Moderna combination shot elicited higher immune responses than currently available vaccines, though I’m sure we will learn more soon. One thing to note is that the influenza component for the dual Moderna vaccine is mRNA derived (for the first time ever), and that may be driving the higher immune responses for flu.

Is there anything else you would like to add?

It needs to be emphasized that we have data on tens of millions of people at this point that show that the vaccines are really safe, and the adverse events that have been reported, like myocarditis and Guillain-Barre, are extremely rare. So look at risk versus benefit for you, your community, your family. In most cases, the benefits clearly outweigh the risks.

This interview has been edited for length and clarity.