The highly transmissible coronavirus variant called delta is now the dominant variant in the United States, and continues to spread rapidly.
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 CDC.
The United States 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.
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.
Do vaccines work on the Delta variant?
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 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.
Should we still be wearing masks?
Mask mandates have already been re-employed in some areas where infections are surging. The CDC issued new guidance on July 27 for areas with high transmission, with director Dr. Rochelle Walensky saying, “The CDC recommends fully vaccinated people wear masks in public, indoor settings to help prevent the spread of the Delta variant and protect others.”
“This includes schools,” Walensky explained. “CDC recommends that everyone in K to 12 schools wear a mask indoors, including teachers, staff, students, and visitors, regardless of vaccination status. Children should return to full-time, in-person learning in the fall with proper prevention strategies in place.”
“With the Delta variant, vaccinating more Americans now is more urgent than ever,” Walensky added. “The highest threat of cases and severe outcomes is happening in places with low vaccination rates and among unvaccinated people. This moment — and most importantly, the associated illness, suffering, and death — could have been avoided with higher vaccination coverage in this country.”
The WHO had already said that, yes, even vaccinated people should mask up. “What I can say is that when we take measures to prevent transmission, we take measures to prevent transmission against droplet and aerosol and airborne,” Dr. Maria Van Kerkhove, WHO’s COVID-19 technical lead, said at the June 25 press conference. “Take those measures. Wearing that mask. Making sure you have clean hands when you put on and you take off a mask. Make sure that if you are indoors, that you have good ventilation. In some situations it is as simple as opening up a window, if it’s safe to do so.”
“We need to ensure that people who are sick and infected don’t get the opportunity to infect others. We have to ensure that the environments we work in, be it the air or the surfaces in the environments we’re in, are appropriately sanitized,” said Dr. Mike Ryan, executive director of WHO’s Health Emergencies Programme. “We have to reduce our own exposure, so we get exposed to less virus, which is the infectious dose, and we have to ensure we’re wearing masks and doing other things to prevent us inhaling particles that will cause us to be sick.”
“What we’re saying is: Once you’ve been fully vaccinated, continue to play it safe because you could end up as part of a transmission chain,” Dr. Bruce Aylward, a senior advisor to the WHO director-general, said at the same press conference last Friday. “I think the first message we want to be careful about is saying, ‘Once you’re vaccinated you can just go ahead and do whatever.’ Yes, you can reduce some measures, and different countries have different recommendations in that regard, but there is still the need for caution.”