Why Are COVID-19 Cases Rising When Vaccinations Are Increasing?
April 09, 2021
While more and more people are getting vaccinated, many medical experts and scientists think COVID-19 cases are rising in a new “fourth wave.” We talked with UH infectious disease specialist Robert Salata, MD, to learn more about the coronavirus variants and likely reasons why cases across the nation recently began going up.
Q. We’re Vaccinating More People Than Ever And Yet Cases Are Rising. Why?
A. It’s likely that many factors are contributing to this. One is that at this point in time, the number of people who are vaccinated fully is only a little over 20 percent of the entire population. So, that still leaves a large majority of the population that has not been fully vaccinated.
At the same time, we're seeing the emergence of variants. The predominant one in the United States is the so-called UK variant, which was described in the United Kingdom as far back as September 2020. In the UK, that variant now accounts for about 80 percent of all their new cases, and in the United States, it's approaching 30 percent. It's in all 50 states right now.
The other thing that's happening is fatigue has certainly set in. People don't want to be bothered by all the precautions and everything else related to COVID-19 anymore. And certain states have lifted their restrictions.
I think all those things together have been associated with this fourth small surge right now, which could get bigger.
This is a fight to the end, a race, if you will, between vaccinating sufficient numbers of individuals and the continued transmission of these infections. All the variants are more contagious than the original virus that we dealt with. These new variants account for an increasing number of cases around the world.
Q. What Exactly Is a Variant?
A. When changes emerge in a virus’s genetic structure, it gives rise to the term called a variant. The virus changes when it is challenged with treatments. Especially now with the wider spread use of vaccines, the virus is going to find a way to survive. And the way to do that is to modify its genetic make-up, mutate, if you will. There have been more than 4,000 variants described.
We're seeing emergence of more and more variants. So far we've been able to provide vaccines that are effective against these variants or mutated strains, but whether that will continue to evolve remains an issue.
But, it's happened before with other viruses. HIV changes all the time. Those changes may not be significant, but if certain components of the virus’s genetic make-up does change, then that could lead to drug resistance and changes that make it necessary for us to modify our treatments. So this is not an unheard-of phenomenon.
It is not surprising that with so much infection around the world, you're bound to see these changes. Some are very innocuous and have had no effect on the clinical course and on deaths related to the virus. But when you start having changes in that spike protein, that's where there can be issues.
Q. How Much of a Threat Are These New Variants?
A. The one that bothers me the most is the South African variant, because it's changed sufficiently in terms of what is called the spike protein. If you ever look at a picture of the coronavirus, it has these projections from the surface. That's a spike protein. That's the very target for our immune response. It's also the component of the virus that allows it to stick to our own human cells, be taken within and make more virus. That's its role in life.
Pfizer and Moderna have done studies in the laboratory where they've taken blood from individuals who have been vaccinated and derived the antibodies that form as a result of the vaccination, and then exposed those antibodies to the variant viruses. They found they were able to neutralize them, except for the South African variant, which was less so. It’s still felt the vaccines will be protective, but we are currently looking at a new study with Pfizer, including at UH.
Q. What Are Vaccine Researchers Doing About the Variants?
A. We did the original Pfizer vaccine trial here, one of 120 sites around the world. Now we're only one of 40 in the world that is testing a booster of the original vaccine to see whether we can induce an even higher immune response, and for folks who have not received a vaccine, a new generation vaccine that will cover the South African variant.
The whole question about whether we're going to need boosters in the future will be informed by studies like this.