Mayo Clinic doctor shines light on delta variant surge
Infectious disease expert says breakthrough cases show that vaccines protect against severe illness, death.
ROCHESTER, Minn. — Just three months ago, the masks came off, and the promised land of normalcy seemed to be within reach.
Then a new, more infectious coronavirus entered stage left, surging in the low-vaccinated Southern states, then engulfing the country. Masking in public areas returned. Amid blaring headlines of skyrocketing infections and hospitalizations, particularly among children, it's been delta, delta, delta.
In a 45-minute news conference Tuesday, Aug. 10, Dr. John O'Horo, a Mayo Clinic infectious disease expert, answered queries from state and local media about this new variant.
What will the next several weeks and months look like? Will we ever be free of masks? What are the chances of a variant more infectious and harmful than delta emerging? And should there be a Minnesota State Fair?
Overall, O'Horo's message was upbeat, but stressed the need for people to get vaccinated if they haven't already done so.
(This Q&A has been edited for length.)
What makes the delta variant different from early COVID strains?
The main thing that makes the delta variant different from earlier strains is that it seems more infective. It is a little bit "stickier," so to speak, with that spike protein. So it takes fewer viruses to cause that initial infection. And once it's there, it divides more rapidly and creates a faster course of disease.
It doesn't transmit fundamentally any differently, but it does mean that there's less room for error when it comes to our other protective measures, especially in settings where we deal with people who are unvaccinated or immune-compromised.
What do we know about the efficacy of the current vaccines against the delta variant?
The effectiveness of the vaccines depends heavily on what you're looking at. The existing vaccines remain highly effective against hospitalizations and death. Where most of the discussion of reduced efficacy (is focused on) is people who are infected but don't know it, because they have an asymptomatic infection that is more common with delta than with prior variants.
But that's not really a failure of the vaccine. It's an indication of how much we can trust the vaccine to keep others safe in a time of high transmission.
What demographic is most affected by the delta variant?
With the delta variant, we're seeing that this is infecting younger people than some of the previous variants have. It's not entirely clear if that's because this variant is really more infectious to younger people or, more likely, because we have vaccinated a larger number of older people, so the most susceptible tend to be younger.
But what we are seeing is that being young is no protection against getting COVID-19 with this delta variant, particularly for those who are too young to get vaccinated.
What do breakthrough cases (like what happened in Provincetown, Massachusetts, where vaccinated people became infected) say about the vaccines?
(Breakthroughs) most commonly refer to somebody who has an infection with COVID-19 despite being vaccinated. I think the definition is overly broad, because many of the people who are vaccinated have little to no symptoms. It ends up making it sound like the vaccines aren't necessarily working as well as they should. What the vaccines were really built for and what they do quite admirably is reduce the incidence of severe disease, meaning those who get hospitalized.
We are seeing some breakthrough hospitalizations where someone is vaccinated and still gets severe disease. In most of these cases, the disease probably would have been worse if they hadn't been vaccinated in the first place. But we're also seeing that these breakthrough hospitalizations tend to happen in people who we expect to have weaker immune systems and might not have the same lasting protection from the vaccine.
If you were running the State Fair, would you keep it open?
The general guidance that's being given by state and local public health authorities has always been fairly consistent about trying to maintain masking where appropriate. And I'm going to harp again on the role of vaccines here. It may be a little late for the fair, but when we look towards any other kind of gatherings that are going to take place in the early fall, the more people who are vaccinated, the less severe the risk will be for these kinds of events.
Do you see an off-ramp, given that COVID is likely to become an epidemic respiratory disease?
I think masking in general areas is going to be a relatively short-term thing for this surge of the delta variant. The guidance offered by the CDC and others has tied the need for masking for vaccinated individuals to local transmission, which is likely to follow that fall that we saw in other countries.
Now it is likely to become endemic, which does mean that in areas where you're working with people who are immune-compromised or unable to be vaccinated, or have weakened immune systems like in health care settings, we're likely going to need to have different precautions and mask longer.
Our plans for normalcy always seem to be upended with the emergence of new variants. This is a very opportunistic disease. What is your concern that there's going to be another variant more dangerous and infectious than the current one?
The more people we see vaccinated, the less of an opportunity there will be for these kinds of variants to emerge. We'll have to remain vigilant as a society for new variants that do require additional measures and require additional vaccines. But at this point in time, the real thing to take away from this is that vaccines are a way to prevent complications, to reduce the susceptibility of communities and individuals to these variants.
I do not think it's a coincidence that we saw these variants come to the Northeast and Midwest, where we have some of the higher vaccination rates, a lot later than they came to the Southern states, where we saw the initial higher rates of (unvaccinated). So, protect your community and protect yourself against these future variants. Get the vaccine.