What are the Lambda and Delta Covid variants and where are they in the US?
Public health officials have raised the alarm about another new coronavirus variant spreading through the world and becoming more prevalent in the United States.
The B.1.617.2 variant, also known as the Delta variant, was first detected in India in March and has since spread rapidly to other countries – and experts warn it’s estimated to be 50 per cent more transmissible compared to past Covid-19 variants.
The current dominant strain in the country was the Alpha variant, otherwise known as the B.1.1.7, which first originated in the United Kingdom before spreading to the US. It was the first strain of concern that developed from Covid-19 after it proved to be more contagious than the original strain.
But the Delta variant appears to be more transmissible and could cause severe disease in individuals. About 10 per cent of cases in the US came from the Delta variant, according to the Centers for Disease Control and Prevention.
Researchers anticipated the B.1.617.2 variant will become the most dominant strain in the US within the next three to four weeks.
B.1.1.7 (Alpha variant)
This variant was first detected in the US in December 2020 after spreading through the UK.
It was roughly 50 per cent more transmissible than the initial strain of Covid-19, which caused concerns about the variant’s impact on Covid-19 death rates and hospitalisations, as well as if the vaccines would still be effective.
The variant has since spread to become the most dominant strain in the US.
At a congressional hearing in June, Dr Rochelle Walensky, the director of the Centers for Disease Control and Prevention, said B.1.1.7 made up 72 per cent of cases in the country.
Due to its high transmissibility rate, the B.1.1.7 has largely made other variants spreading through the US obsolete – leading to a rise in coronavirus cases, hospitalisations, and deaths.
But, courtesy of the Covid-19 vaccines, the variant caused a smaller spike in cases and hospitalisations compared to what officials initially anticipated.
Early research has indicated that the available vaccines were effective against the variant.
B.1.351 (Beta variant)
The B.1.351 variant was first discovered in South Africa in December 2020 amid high infection rates and hospitalisations from the novel virus.
This variant then spread and was first detected in the United States in January 2021, largely impacting portions of the East Coast like New York.
Forecasters in February 2021 warned of a deadly surge from the B.1.351 variant, given how transmissible it was on the population.
While this variant has caused Covid-19 deaths in the United States, the anticipated surge never reached full peak.
What likely helped stop the variant from having as high of an impact on the country was the vaccines.
A recent study found that both Pfizer and Moderna’s Covid-19 vaccines were effective in preventing severe disease, even with the B.1.351 variant circulating communities.
The trial data “provide the first clinical results that a vaccine can effectively protect against currently circulating variants, a critical factor to reach herd immunity and end this pandemic for the global population,” said Ugur Sahin, chief executive officer at BioNTech, the vaccine arm of Pfizer, in a statement released in April.
P.1. (Gamma variant)
The P.1 variant, also known as the Gamma variant, was detected in infected travellers from Brazil when they were required to do a routine screening at an airport in Japan in January 2021.
That same month, the variant was also detected in the US.
Similar to the Beta variant, the strain is more transmissible compared to the initial Covid-19 virus, but it hasn’t spread as rapidly compared to the B.1.1.7.
The Pacific Northwest has seen the largest uptake of infections from the gamma variant compared to other areas of the country.
In Washington state, for example, the variant accounts for a majority of recent hospitalisations.
“It’s very effectively outcompeting the alpha and delta variants, and the rest of the country isn’t seeing this,” Dr Scott Lindquist, Washington state’s acting health officer, told the Spokesman-Review.
“Many of our counties here are seeing the gamma variant. It’s got the highest hospitalisation rate of all of our variants.”
Both Pfizer and Moderna’s vaccines have been thus far effective against the gamma variant, according to recent studies. But health experts were worried that the rise of more and more highly transmissible Covid-19 variants could offer a pathway for the novel virus to eventually escape vaccine protection.
Scientists were tracking the gamma variant along with other variants of concern to better determine the potential impact on population groups.
B.1.617.2 (Delta variant)
Covid-19 cases were higher in about half of the states in the US compared to the previous week, and experts have credited the spread of the B.1.617.2 (Delta variant) as the cause for the recent surge.
Twelve states including Arkansas, Nevada, and Missouri are now considered “high risk” for Covid-19. This was due to an uptake in infection rates combined with low vaccination numbers compared to other parts of the country.
The 12 states at high risk from Covid-19, according to Covid Act Now, are: Arkansas, Florida, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Nevada, Oklahoma, South Carolina, Utah, and Wyoming.
In Missouri, 96 per cent of new Covid-19 cases were due to the Delta variant – making it the state in the country with the largest spread of the strain among its residents. The state also has a vaccination rate below 40 per cent of residents fully vaccinated, which was below the federal rate of 47.4 per cent
Across the US, the Delta variant has spread rapidly through the country and now accounts for about 10 per cent of cases – with this proportion doubling about every two weeks.
Researchers have said the Delta variant is likely more transmissible and deadlier compared to the Alpha variant. It will likely become the main Covid-19 strain in the US within the next month.
Dr Anthony Facui, the nation’s leading infectious disease expert, warned that areas with low vaccination rates in the country would likely be most impacted by the Delta variant in the coming months.
“I don’t think you’re going to be seeing anything nationwide, because fortunately we have a substantial proportion of the population vaccinated. So it’s going to be regional,” he told NBC’s Meet the Press.
Health experts have implored unvaccinated Americans to receive a Covid-19 vaccine in the coming months amid the continuous spread of highly infectious variants.
Nearly 10,000 people died from Covid-19 in June, and Dr Fauci said a majority of those deaths were likely “avoidable and preventable” had people received one of the available vaccines.
“If you look at the number of deaths, about 99.2 per cent of them are unvaccinated and about 0.8 per cent are vaccinated,” Dr Fauci said.
“No vaccine is perfect, but when you talk about the avoidability of hospitalisation and deaths … it’s really sad and tragic that most all of these are avoidable and preventable,” he added.
Early research has shown the Delta variant impacting vaccine effectiveness.
A study conducted of Pfizer’s vaccine in Israel found that the vaccine protected 64 per cent people amid the Delta variant outbreak, which was down from the 94 per cent of people previously protected.
The vaccine was still effective in preventing severe disease on hospitalisation, though, with a 94 per cent effectiveness rate.
C.37 (Lambda variant)
The Lambda variant was first identified in Peru and has been detected in cases as early as December 2020.
Since then, it has become the dominant strain in the South American country and now accounts for about 80 per cent of new infections.
This variant, like others, spread to other countries and has now been detected in about 30 nations, mostly in Latin America, and the UK. To date, no cases were reported in the US.
The World Health Organization designated the variant as one of interest on 14 June.
“Lambda carries a number of mutations” that may have led to “potential increased transmissibility or possible increased resistance to neutralising antibodies,” the WHO said.
In Peru, the country currently has the highest mortality rate compared to any other nation, according to data from Johns Hopkins University – which has sparked concern among health experts about the impact of the Lambda variant for other nations.
Limited research of the variant was available, as scientists work to learn more about its transmissibility and ability to neutralise antibodies.
But a new study – which has not yet been reviewed by other scientists and is based on tests on samples from healthcare workers in Chile – suggested that the Lambda variant was more infectious than the Alpha and Gamma variants.
The study also suggested that the variant has a higher “immune escape”, compared to the Alpha and Gamma variants, for people in Chile who received Covid-19 antibodies from China’s CoronaVac (Sinovac) vaccine. No other vaccines were analysed in the new study.
