The delta variant, a more contagious and deadly strain of the COVID-19 virus, is spreading quickly throughout Indiana and is now the most dominant strain.
Here’s what you need to know:
What is a variant?
In general viruses mutate as they spread. Some of these mutations fizzle out and others become more prevalent for various reasons, according to the Indiana Department of Health.
The United States and Indiana have seen a number of variants of the virus that causes COVID-19 in the past 16 months. At first, the most common variant was the alpha variant, first identified in the United Kingdom, known as the B.1.1.7 variant.
More recently the delta variant, first identified in India and known as the B.1.617.2 variant, has become more dominant.
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Some are known as variants of interest, which means the Centers for Disease Control and Prevention scientists are monitoring them. Others are variants of concern, which means they may be more transmissible, cause more severe disease, or be less vulnerable to vaccines and therapeutics. Both the alpha and delta variants are considered to be variants of concern.
A variant could also be labeled a variant of high consequence, meaning it has increased capacity to cause severe disease and or is more impervious to drugs or vaccines. At this point the CDC has not deemed any COVID-19 strains a variant of high consequence.
How is the delta variant different?
The delta variant is thought to be far more transmissible than the original strain of coronavirus. The variant is about 60% more transmissible than the alpha variant, which was already more readily transmitted from person to person than the original variant, according to the American Medical Association.
Some studies have suggested that this variant may also cause more severe disease than other strains.
How common is the delta variant in Indiana?
About 70% of the positive COVID-19 samples tested this month have been the delta variant, according to the state’s COVID-19 dashboard. This represents an increase of nearly 40% from the previous month.
Only about 15% of samples tested have been the alpha variant, a decrease of nearly 40% from the percentage one month ago.
State health officials declined in an email to provide county-level specifics about the delta variant. The variant has been found in samples sequenced from almost every county, state health officials said.
“Because only a small percentage of samples are sent for sequencing, a breakdown by county level does not accurately reflect the prevalence of a variant in a given county,” said spokeswoman Jeni O’Malley in an email. “For public health purposes, it is more useful to understand what percentage of samples is testing positive for a variant and that the variant is present.”
Nationwide, the delta variant is responsible for nearly 62% of all COVID cases, according to the most recent data from the Centers for Disease Control and Prevention.
What are symptoms of the delta variant?
COVID-19 in general can cause a variety of symptoms, ranging from respiratory to gastrointestinal distress.
A British app that encourages people who have COVID to report their symptoms online has seen a shift in the most common symptoms among those infected who are unvaccinated.
The ZOE COVID Symptom study now lists headache, sore throat, runny nose, and fever with persistent cough coming in fifth as the top symptoms now that the delta variant has become the dominant strain circulating. Loss of smell was ranked number nine and shortness of breath, once a very common symptom, number 30.
Do the Pfizer, Moderna and Johnson & Johnson vaccines protect against delta?
Studies suggest that three vaccines currently in the United States offer some protection against the delta variant, according to the CDC, but it is not yet known just how effective they are.
In addition, some of the studies have offered conflicting views. A study performed in Scotland suggested that the Pfizer vaccine’s effectiveness might decrease slightly when faced with the delta variant and be about 79% effective.
Another study performed in Israel found the Pfizer vaccine was about 64% effective when it came to preventing infection against the delta variant but 93% effective in preventing serious illness and hospitalization.
Earlier this week, a study appeared online, suggesting that the Johnson & Johnson vaccine may not be as effective against the delta variant as the other two. The author said that his study, which has not yet been peer reviewed, open the door for booster shots for those who received the J&J shot.
What about the delta variant and unvaccinated people?
This is the population that has public health officials most worried. Because the delta variant is far more easily transmitted than other variants, those who are exposed and have no protection are more likely to contract the variant.
The majority of people currently hospitalized for COVID-19 in Indiana — and the country as a whole — are those who are unvaccinated.
There have been 152 people fully vaccinated people in Indiana hospitalized for what’s known as breakthrough infections, about 0.005% of all fully vaccinated people, according to the state’s dashboard.
What is the lambda variant?
Recently the World Health Organization added the lambda variant, first identified in Peru, as a variant of interest. This variant is thought to be contributing to increased COVID spread in Latin America and has now been found in at least 29 countries, according to the World Health Organization.
In the United States, the lambda variant has been implicated in fewer than 700 cases.
It’s unclear whether or how much that strain is infecting people in Indiana. Because the lambda variant is not yet a variant of concern in the United States, Indiana does not include a listing for it on the state dashboard.