“I have to be honest – the last thing I think about before I go to bed are the variants and the first thing I think about in the morning are the variants,” Lindquist said in a briefing this week.
And while federal health officials warn the most against the Delta variant – the B.1.617.2 strain first seen in India – other variants are also gaining ground in parts of the United States.
One of them is the Gamma variant, also known as P.1, which quickly spread to dominate in Brazil.
So far, none of the more common variants shows a great ability to evade the effects of a full vaccination. But several have shown the ability, both in the lab and in real life, to re-infect people recovered from a natural coronavirus infection and infect people who have only been partially vaccinated.
But people who were fully vaccinated had a strong, broad immune response that should support the variants, vaccine experts agreed.
Gamma is classified as a variant of concern by the United States Centers for Disease Control and Prevention. A worrying variant shows evidence of increased transmissibility, more severe disease, decreased effectiveness of antibodies, decreased effectiveness of treatment or problems with diagnosis, according to the CDC.
According to the CDC’s own variant tracker, Gamma has been detected in every state where the CDC has variant information. According to the most recent monitoring data, the gamma prevalence is above 15% in several regions, including the West and Northeast.
Increasing frequency in several states
Dr Philip Chan, consultant medical director for the Rhode Island Department of Health, said that although the predominant strain in the state is still the Alpha variant – also known as B.1.1.7 and identified for the first time in UK – the Gamma variant is common in Rhode Island.
“If you look at the trends over time, what we’ve seen over the last few weeks is that around 20% of all the variants were the Gamma variant and this has remained stable over the past few weeks,” he told CNN.
According to the California Department of Public Health, Gamma accounted for 10% of all specimens sequenced in May and “has increased in all parts of California.”
“Public health officials are concerned about the Gamma variant and several other variants of concern, including Alpha and Delta, which have increased in frequency in California and may have a moderately diminished response to some antibody treatments or be more transmissible,” he said. the department told CNN. in an email.
In Illinois, gamma accounts for more than 25% of sequenced variants, according to state health data. According to NowCast data from the US Department of Health and Human Services, the gamma prevalence in the United States has increased steadily since mid-March.
Gamma: more resistant to vaccines, antibody treatments
Current evidence suggests that gamma can resist the effects of antibody treatments.
In nine states, the HHS has halted distribution of two monoclonal antibody treatments from Eli Lilly and Co, citing reduced efficacy against the Gamma and Delta variants.
“The results of in vitro tests used to assess the sensitivity of viral variants to particular monoclonal antibodies suggest that bamlanivimab and etesevimab administered together are not active against variants P.1 (Gamma) or B.1.351 (Beta) HHS said Wednesday.
According to the CDC, the Gamma variant exhibits “dramatically reduced sensitivity” to Lilly treatment and reduced neutralization of post-infection and post-vaccine immunity.
This resistance to antibodies, explains Dr Peter Hotez, presents a key problem in this variant.
“If you are not vaccinated or if you only have one dose of the vaccine, you are vulnerable,” Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told CNN.
“And right now the only effective treatment we have if you give it early is the monoclonal antibody, so if it has to escape the monoclonal antibody, that’s really problematic. “
Hotez said the impact on immunity is related to mutations – three of them – that change the shape of the virus in the variant, making it harder for immune system proteins called antibodies to recognize and s ‘hang on it.
“The more antibody resistant variants have the potential to cause vaccine protection problems,” John P. Moore, professor of microbiology and immunology at Weill Cornell Medicine, told CNN.
Moore said in a ranking of some key variants, Gamma was shown to have greater antibody resistance than Alpha, but comparable resistance to Delta.
“That doesn’t mean it’s going to explode vaccine protection in the United States,” he said.
This is because licensed vaccines generate much more protection than natural infection produces.
“Both doses, Pfizer and Moderna, should be able to handle this variant quite well because they are so potent. J&J might run into problems, but would probably still have enough power to keep people out of the ICU, which is the most important thing, ”said Moore.
However, the spread of variants creates an environment where the strength of the vaccination may not last forever.
“The worrying part about all of these variants is that they keep popping up,” said Ramon Lorenzo Redondo, infectious disease specialist at the Feinberg School of Medicine at Northwestern University. He said that in areas with low vaccination, the variants could spread, replicate and evolve even faster.
“In that situation, you could be pushing the virus to adapt… not only to transmit faster – they can – but also to evade immunity,” he said.
“Some of these lines that have already evolved to escape, at least, natural immunity. Yet they are not able to escape immunity produced by a vaccine, ”he said. “If you allow this high number of cases in unvaccinated or not fully vaccinated countries, you are entering a danger zone. “
Whenever a virus infects someone, it replicates and evolves – and eventually a highly vaccine-resistant variant could emerge.
One in a field of many variations
This is why the White House is pushing so hard to get people fully immunized.
“What we’re seeing in a highly vaccinated population, especially in the United States, is that all of these lineages are controlled,” Redondo said.
“So even (with) these highly transmissible (variants), if you have good immunization coverage, it looks like nothing is going to get out of hand so far. “
Variants can also be mutually exclusive.
Moore told CNN that Delta has shown its ability to “outperform” other variants of Covid-19.
“This blew up the incidents of Alpha infection in the UK late last year,” he said – one of many cases where the variants have come and gone.
“We have seen this model of a transmissible variant dominate a less transmissible variant. We’ve seen it four times now, ”Moore said.
“We don’t know if Gamma has this ability,” he said.
“If Delta really takes over, which a lot of people think it might be in the US based on what we’re seeing in the UK in particular, then Gamma might just be ousted. And so, it is difficult to predict the future. We therefore do not have information on the relative transmissibility of Gamma. “
Vaccines are always our best shot
The spread of variants, including, but not limited to, Gamma, should reinforce the need for everyone to be fully immunized, Moore said.
“One dose will not be enough for these resistant variants. A dose of mRNA isn’t fully vaccinated, especially when you run into these more resistant variants, ”Moore said.
“When you’re dealing with states like Alabama, Arkansas, Mississippi – that part of the country where vaccination is low – people there are very vulnerable to a more communicable variant like Delta, if it takes off, (or ) Gamma. “