Worried about Delta? Here are 7 things you need to know.

What is the Delta variant, and how does it differ from the original strain of Covid-19?

Sars-COV-2, more commonly known as the coronavirus or Covid-19, first emerged in late 2019 and began to spread in the United States in early 2020. Like all other viruses, this virus began to adapt and mutate.

Scientists have been tracking several variants of Covid through genetic tracing. The Delta variant is one specific variant of the original coronavirus that was first identified in late 2020, and in early July, it became the dominant form of Covid that is circulating in the United States.¹

The Delta variant has a mutation on the spike protein. In other words, the structure of this virus is different from the original strain of Covid-19. This mutation has enabled the virus to spread more easily and to also break through the defenses provided by the three Covid vaccines.

What do we know about the Delta variant?

The Delta variant is quickly becoming the dominant strain of Covid. Current ADPH data indicates that most COVID-19 infections in Alabama are the Delta variant.²

The Delta variant is six to ten times more infectious than the original virus. While that may sound scary, Dr. Vaughn says, “It’s important to note that the more infectious a virus is, it is usually equally less lethal. This means that if a virus is 5 times more infectious, it should also be 5 times less lethal. In almost all viral mutations, a mutation can only become more infectious if, at the same time, it’s less deadly. In a single-stranded, non-segmented RNA virus (like Covid), a virus is unlikely to become both more contagious and more deadly.”

Dr. Vaughn also says, “We can learn a lot from the Spanish flu pandemic of 1918. A farmer in Hutchison, Kansas got the flu from a pig he was caring for. He was called up to a training camp in Boston during World War I, bringing the virus to the camp. From there, it spread throughout the city of Boston.”

“In Boston, only 20% of the population got the flu, but a huge percentage of those people died. As the flu spread throughout the United States, it mutated. By the time the flu arrived in San Antonio nine months later, it had become much more contagious - and much less lethal. Nearly 80% of the population of San Antonio got the flu, but the death rate there was significantly lower than it was in Boston.”

“The behavior of the virus in San Antonio is consistent with the fourth wave of the flu pandemic; similarly, we are in what appears to be the fourth wave of Covid-19 with the Delta variant. In this fourth wave, we’re beginning to see that Covid cases and deaths have decoupled. In other words, while the cases may be rising, we are not seeing the proportional increase in Covid deaths that we saw earlier in the pandemic.” Dr. Vaughn explains.

How will Delta impact those who have been vaccinated?

The Delta variant developed in countries with high vaccination rates, such as Great Britain and Israel. Dr. Vaughn says, “The Covid vaccines currently in use instruct your body to make one antibody to the subunit of one protein on the surface of the virus. These are unlike any vaccines we’ve ever used before, and we’ve never developed a vaccine for a virus during a pandemic. When there are high levels of transmission of any virus, that virus can replicate and create multiple variants. Eventually, a variant emerged that had adapted enough to bypass the narrow, targeted, and short-lived protection provided by the vaccines.”³

Dr. Vaughn goes on to explain, “Imagine finding out that there’s a group of robbers planning to break into houses in your neighborhood tonight. In response, you lock your front door, but you leave your windows and side door unlocked, assuming the robbers aren’t coming back the next night. When the robbers come to your house and find out the door is locked, they may move on to the next house to find an easier target. If they don’t come back, your protection worked and your house is safe. That’s how the vaccines work - they lock your front door.”

He continues, “If they come back the next night, they already know your front door is locked, so they’re going to look for another way in. They may discover that your side door is unlocked, or maybe they can get in through your windows. If the robbers are persistent, they’re going to eventually find a way in. You’re not really protected, but the locked door makes you believe that you are. That’s what happened with the Delta variant: it found another way in.”

This means that those who have been vaccinated can in fact be infected with the Delta variant. The vaccine provided protection for a while, but eventually, the virus adapted and found a way to infect those who have been vaccinated.

Is the vaccine worthless now? Why are there breakthrough infections?

It’s important to know that the vaccine is not worthless. For those who have not had a previous Covid infection, the vaccines are incredibly effective at preventing serious illness, hospitalization, and death. Most Covid-related deaths in Alabama are among people who have either not been vaccinated or not had a previous infection.⁴ At this point, your body has a much better chance at fighting a Covid infection if you’ve already had Covid or one of the vaccines.

A breakthrough infection, as recently redefined by the CDC, occurs when someone who has already had one of the Covid vaccines gets infected with the virus and is hospitalized. Dr. Vaughn says, "Breakthrough infections are expected, and any positive Covid test after vaccination should be considered a breakthrough infection; however, the CDC has changed this, which makes the real data difficult to determine. Many breakthrough infections are mild - but so is the Delta variant itself at this point." At the time of publication, it appears that 1 in 10 true breakthrough cases require hospitalization.

Dr. Vaughn says, “You’re now just as likely to get Covid as a vaccinated individual as an unvaccinated individual who hasn’t had a prior infection. But at this point, the outcome of your infection will be much better if you’ve already gotten a vaccine.”

If you have not yet been vaccinated, there may be reasons to hold off on getting your vaccine until this current wave dies down. Dr. Vaughn says, "In general, it's not a good idea to get vaccinated for any virus in the middle of rising cases. You won't receive full protection from your vaccine for 6 to 8 weeks, and in the first two weeks after you receive your vaccine you're actually more vulnerable to a Covid infection. And if you do get Covid after a recent vaccination, you're more likely to contribute to the creation of escape variants."

Because of the changing dynamics of the virus in the context of the fourth wave, Dr. Vaughn advises those who haven't had a previous Covid infection and are considering getting the vaccine to be sure to talk with their primary care doctor before getting vaccinated.

What about those who've already had a previous Covid infection?

Data from Israel indicates that those who have had a prior Covid infection do not get infected with the Delta variant. Dr. Vaughn says, “If you’ve never had Covid and you haven’t been vaccinated, you have no antibodies to protect you against any kind of Covid infection. If you’ve had one of the vaccines, you have one type of antibody protecting you. But if you’ve had Covid before, you have a robust immunity to Covid with antibodies for multiple surface proteins. According to what we’re seeing in Israel, the risk of getting a second Covid infection is so small it isn’t even quantifiable.”

In other words, a previous Covid infection is the best protection you can get for the new Delta variant. Dr. Vaughn says, “Think back to the neighborhood robbers. If robbers broke into your house, you’d probably take action to prevent any future attacks such as changing the locks and adding an alarm system. If you’ve had a Covid infection, it’s like you’ve rebuilt your house out of steel, changed all the positions of the doors and windows, added new locks, and included a state-of-the-art alarm system on top of it all. Even the most persistent robbers have almost no chance of getting into your house now.”

If you’ve had a previous Covid infection, you may never need to get vaccinated. New research out of Emory indicates that the antibodies produced from a prior Covid infection provide lasting immunity through durable antibody responses.⁵

In fact, Dr. Vaughn says that people with high antibodies from natural infection are seven times more likely to experience an adverse reaction to a Covid vaccine.⁶ If you’ve had a positive Covid test in the past, talk with your doctor before getting vaccinated. You should also consider getting your antibodies tested before getting a vaccine; this simple test can tell you if you already have natural protection against Covid.

What about kids under the age of 12 who can't get vaccinated yet?

Covid has never been a serious threat to children. While a very small percentage of children do get seriously ill, the overwhelming majority of children who get sick with Covid will have a very mild illness. Dr. Vaughn says, “Based on our experience at MedHelp, children with Covid just do not have significant or similar symptoms to their adult counterparts. For example, children with a headache and no other symptoms may test positive for Covid. In the previous Covid wave, we were maybe detecting 1 in 4 cases in children; in this wave, we're detecting about 1 in 10 because the symptoms are so mild.”

While children with severe cases of Covid have been making the news, Dr. Vaughn says, "Many more children are currently in the ICU at Children’s Hospital of Alabama with RSV and other common respiratory viruses than Covid. The children who do get seriously ill are almost always patients who have hemoglobinopathies or are in otherwise immunocompromised states."

According to Dr. Vaughn, “With the Delta variant circulating, it’s much more likely that your child will get sick with Covid if they haven’t already had it. But if they do get sick, they’ll get even less sick than they would have a year and a half ago. There is truly no need to worry.”

The Delta variant is also much more transmissible than wild Covid, so kids are now much more likely to give Covid to their parents. Dr. Vaughn says, "Parents who have not had a previous Covid infection and have any significant health issues or are older than 50 years of age should talk with their primary care doctor about getting vaccinated to protect themselves against serious illness."

What should I do if I get sick with Delta?

If you get sick with the Delta variant, there’s no need to panic. Dr. Vaughn says, “If you haven’t already had Covid, a Delta infection is pretty likely. If you’ve been vaccinated, you may not even know you’re infected. But you shouldn’t feel guilty or ashamed if you get sick with Covid. You didn’t do anything wrong. And remember, a Covid infection will provide you with more robust immunity.”

“There’s also no need to get mad if you were vaccinated and still got sick. Medicine and science aren’t perfect, and sometimes we’ll try things that may not be perfect either. The data pointed to the vaccines as the best way to help us through this pandemic. The Covid vaccines are very different from other vaccines historically, so don’t let this undermine your faith in other vaccines.”

In light of the spreading Delta variant, Dr. Vaughn wants everyone to remember, “Every pandemic in history has eventually burned out. Covid is no different. Our bodies are designed to weather these infections.”

If you do have symptoms of Covid, get tested to determine your next steps.

References:

¹COVID Data Tracker. Retrieved August 01, 2021. https://covid.cdc.gov/covid-data-tracker/#variant-proportions

²Alabama Department of Public Health: State Health Officer News. Retrieved August 04, 2021. https://www.alabamapublichealth.gov/news/sho-message.html

³Rella et al. Rates of SARS-CoV-2 transmission and vaccination impact the fate of vaccine-resistant strains. Scientific Reports. July 30, 2021. https://doi.org/10.1038/s41598-021-95025-3/p

⁴Alabama Department of Public Health: State Health Officer News. Retrieved August 04, 2021. https://www.alabamapublichealth.gov/news/sho-message.html

⁵Cohen et al. Longitudinal analysis shows durable and broad immune memory after SARS-CoV-2 infection with persisting antibody responses and memory B and T cells. Cell Reports Medicine 2, 100354 July 20, 2021.

⁶Raw et al. Previous COVID-19 infection, but not Long-COVID, is associated with increased adverse events following BNT162b2/Pfizer vaccination. Journal of Infection. May 29, 2021. DOI: https://doi.org/10.1016/j.jinf.2021.05.035