Cases of coronavirus are leveling off and more Texans are getting vaccinated.
Over two million of people have gotten at least the first dose of the COVID-19 vaccine. But there could be a hitch. There are COVID variants which may be more contagious or may not respond as well to the vaccines.
Dr. Paul Klotman, president and CEO of the Baylor College of medicine says we're beginning to see the flattening of the curve nationally. But there is some worry over variants.
The first virus that started in Wuhan, China was quickly replaced by a strain which was more infectious and became the dominant strain in the United States.
The vaccine should do fine against the B.1.1.7. strain from the UK which started in the Southern British town of Kent. "That particular mutation leads to about a 70% increase in the binding affinity of the spike protein to the receptor. That led to a huge spike in increases in Southern England." He says it looks like it maybe slightly more lethal. "The good news is the Pfizer and the Moderna vaccine are shown to be effective against that mutation. The vaccines should take care of that particular variant."
The second new variant was identified in South Africa. That has the same mutation as was seen in the UK but has additional mutations. "If you look at patients who have been infected with SARS COV2 and take their plasma and look at neutralizing antibodies to that particular viral strain, it looks like there's about a ten fold reduction in the ability of the antibodies to bind and neutralize that. If you take the people who have been vaccinated, there's about a six fold decrease in the neutralizing activity. That does not mean it won't work. With a 95% vaccine, it may reduce the effectiveness a little bit but it does not mean it won't work."
The most troubling strain is the Brazilian mutation. P1 comes from the Amazonian city of Manaus. "70% of that population had been infected already and all of a sudden there's this huge spike. The concern is this new variant is even more infectious and potentially might avoid the effects of the vaccine." There has been one US case of that variant, a person in Minnesota who had traveled to Brazil.
He says studies are underway to add an additional booster to the Moderna vaccine to increase antibodies. He says "We've talked about how easy it is with the mRNA platform to change. There's a sequence of nucleotides that reads out and is translated into these amino acid building blocks. It's just like a typewriter. You can type a new sequence and create a whole new vaccine. It's possible that if these variants really do evade the neutralization from the current vaccines, we can roll out new vaccines that address new variants. That's what we do with flu, every year." He says the good news it's unlikely it will annual as we lower the virus worldwide.
He says every time a viral copy is made, there's a potential for an error. "When there are trillions and trillions of viruses being replicated, there's all these mutations. The vast majority don't do anything. The other make it less fit, but every now and then you get one that makes the virus more fit."
He says the less the virus replicates, the less likely you are to have mutations. The best way to make that happen is a global vaccination campaign." He also advises mask wearing and social distancing.
