COVID-19: Understanding Its Variants
Since late 2019, COVID-19 has been circulating and evolving. It’s infected countless people and claimed an estimated 4.5 million lives — nearly 700,000 in the U.S. Each time a major outbreak tamped down by social distancing, vaccination and other public health efforts, the virus finds a way back – changing so that it evades some of the countermeasures against it. This has led to a number of new strains or variants of the original virus.
What Are Coronaviruses?
COVID-19 is a disease caused by the coronavirus SARS-CoV-2. Coronaviruses are a large family of respiratory viruses that generally cause mild to moderate upper respiratory tract symptoms that affect the nose and throat -- like a common cold. However, three new coronaviruses surfaced over the last twenty years – SARS, MERS and COVID-19 – that have caused extensive serious illness and death.
What is COVID-19?
COVID-19 is a disease with a wide range of symptoms and complications. Most people experience mild to moderate symptoms and are able to recover within a few weeks without special treatment. In some cases, symptoms linger long after their initial infection and are referred to as long COVID-19. People who are older or managing chronic conditions are at risk for developing serious, potentially life-threatening complications such as pneumonia and sepsis. However, there have been many unexplained COVID-19 cases that have caused younger, healthier people to become gravely ill or die.
As viruses circulate through a population, they undergo evolutionary changes or mutations. After a virus accumulates enough mutations, it’s considered a variant. And if variant develops new biological capabilities, it’s becoming a strain. Viruses mutate at their own rate – some quicker than others -- and can weaken or strengthen with each mutation. One example is influenza. It’s constantly mutating, which is why we need a new flu vaccine every year.
COVID-19 Variants in the United States
Here are all the current variants and what we know about them:
|Alpha B.1.1.7||U.K.||Spreads quickly
||Increased risk of severe complications||Yes||Not highly responsive to monoclonal antibody treatments|
|Beta B.1.351||S. Africa||Spreads quickly
||Possible, but not more than another variant||Yes||Yes, although certain monoclonal antibodies are less effective at fighting this variant|
|Gamma P.1, P.1.1, P.1.2||
||Possible, but not more than another variant; at one point, the Gamma variant was responsible for the most COVID-related hospitalizations.||Yes||Yes, although certain monoclonal antibodies are less effective at fighting this variant|
& Delta Plus AY.1, A.Y.2, AY.3
|Delta spreads very quickly; Delta Plus is unlikely more transmissible than Delta. The difference between the two strains is the number of mutations. Delta has a number of them, while Delta plus only has one – K417N.||Much higher risk of severe complications
||Yes, studies have found the vaccine to be very effective in preventing severe complications.||Yes, although certain monoclonal antibodies are less effective at fighting this variant|
|Zeta B.1.621||Colombia||Spreads quicker than other variants.||Studies have found that the Delta Plus variant has the ability to bind easier to lung cells and might be more resistant to therapies.||Experts do not have enough information currently to provide guidance.||Yes, probably similar to Delta|
|Epsilon B.1.427/B.1.429||California||At one point it was spreading quickly, as it had three spike proteins. However, transmission slowed in February 2021, and in July 2021, epsilon was deescalated and now considered a variant of interest, not concern.
||Seems to have similarities to Delta variant||Experts do not have enough information currently to provide guidance.||Responds to some monoclonal antibody treatments|
|Eta B.1.525||Nigeria/U.K.||There have been no new reported cases since July 2021.
||Possible||Carries the E484K (or eek) mutation, which does not respond well to vaccines.||Carries the E484K (or eek) mutation, which does not respond well to convalescent plasma or monoclonal antibodies.
|Iota B.1.617.1||New York||
It’s only accounted for three percent of all cases since the pandemic began and fewer than 10 cases were reported during the first week of September 2021.
|Possible||Experts do not have enough information currently to provide guidance.||Currently being watched for reduced susceptibility to monoclonal antibody treatments.
The last reported case in the U.S. was in June 2021.
|Possible||Experts do not have enough information currently to provide guidance.||Spike proteins appear to make it less responsive to monoclonal antibody treatments and vaccines.|
At first, Lambda appeared to spread quicker than some other variants; however, has slowed over time. At one point, it was responsible for 10 percent of all COVID cases in South America. Now, it’s only accountable for about 2.4 percent. The last case in the U.S. was reported in August 2021.
|Possible||Results from one study conducted in a lab and not peer reviewed suggests that the vaccine may not be as effective against this variant. But one study is not enough information to provide guidance.
Monoclonal antibody treatment does not appear to lower antibody titer and convalescent plasma was about 3.3 fold more resistant.
|Mu B.1.621 and B.1.621.1||Columbia||
This variant seemed to spread quickly, as it identified in 39 countries, including the U.S. since January 2021. However, the spread drastically slowed down. In the U.S., the variant was responsible for only 0.2 percent of cases during the third week of August 2021.
Studies suggest the vaccine may provide some protection against this variant. A Japanese study found this variant to be more than seven times more resistant to it.
|The World Health Organization reports that this variant has mutations that lower the effectiveness of natural immunity, monoclonal antibody therapy and vaccines.|
Initially, this variant was considered a variant of concern by the World Health Organization but has since been downgraded to a former variant of interest.
|Possible||Experts do not have enough information currently to provide guidance.||No information available.|
If you have questions about COVID-19 and its vaccine, please talk to you doctor. And make sure you continue to social distance, wear a mask in public, disinfect commonly used surfaces and strengthen your immune system. If you haven’t been vaccinated against COVID-19, consider getting the vaccine. The vaccines are highly effective against severe illness and hospitalization, even in emerging variants.