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Updated 9 July 2021

The Delta variant of COVID-19, first reported in India and now identified in over 85, is the “most transmissible” of the variants identified so far and is spreading rapidly among unvaccinated populations, said WHO chief Tedros Adhanom Ghebreyesus. The US, which has been celebrating reopening across several states with over 48.1 percent of its adult population vaccinated, is not immune to this threat. 

Keep reading to know about the Delta variant in the UK.

What is the Delta Variant

The Delta variant was first detected in India around late 2020. The variant, also known as B.1.617.2has been described as a ‘double mutant’. This term is used to refer to two main mutations E484Q and L452R, in spike proteins. 

The spike protein is the part of the virus that it uses to penetrate human cells. Double mutation in key areas of the virus’s spike protein might increase risks and allow the virus to escape the immune system. 

The variant, which was earlier classifies as a “variant of interest” has now been announced to be a “variant of concern” by the WHO. A mutation is elevated from a “variant of interest” to a “variant of concern” (VOC) when it shows evidence of fulfilling at least one of several criteria, including easy transmission, more severe illness, reduced neutralization by antibodies or reduced effectiveness of treatment and vaccines.

Delta plus variant

The Delta Plus variant was formed due to a mutation in the Delta or B.1.617.2 variant. The Delta Plus variant (B.1.617.2.1 or AY.1) is characterized by the K417N mutation in spike protein. 

The Delta plus variant spreads more easily, binds more easily to lung cells and is potentially resistant to monoclonal antibody therapy, which is a potent intravenous infusion of antibodies to neutralize the virus.


Symptoms of Delta variant

The symptoms caused by the delta variant are believed to be unlike the ‘original’ COVID symptoms. There have been reports suggesting the presence of headache followed by sore throat, runny nose and fever. Symptoms such as cough and loss of smell are much rarer now.

The following is the Centers for Disease Control and Prevention’s (CDC) updated list of COVID-19 symptoms:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

Delta variant spread in the US

Over the past four weeks, the share of the delta variant in new covid cases in the US is 51.4 percent. This means the delta variant is now the dominant coronavirus strain in the US.

In parts of the country, new delta infection cases have reached more than 80 percent share of the total new infections. Midwestern states such as Missouri, Kansas and Iowa are among the ones affected.

In Western states such as Colorado and Utah, 74.3 percent of delta infections have been observed, while Southern states such as Texas, Louisiana, Arkansas and Oklahoma, the delta percentage is around 58.8 percent according to CDC estimates.

Are the existing vaccines in the US effective against Delta?

The US has approved three vaccines, namely Pfizer/BioNTech, Moderna and Johnson & Johnson. 

Pfizer/BioNTech: A study by researchers from the University of Texas together with Pfizer and BioNtech shows that antibodies elicited by the vaccine are able to neutralize Delta, albeit at reduced strength. Alon Rappaport, Pfizer’s medical director, has also said that the data from labs and places where the Delta variant has spread vastly demonstrate an efficacy of around 90 percent in preventing the coronavirus disease.

Moderna: The Moderna vaccine is reported to have shown promise against the Delta variant based on a lab study. The lab study was conducted on blood serum from eight participants obtained one week after they received the second dose of the mRNA -1273 vaccine. Although a modest decrease in response compared to the original strain was observed, the Moderna vaccine was far more effective in producing antibodies against the Delta variant than it was against the Beta variant.

Johnson & Johnson: Less is known about how well the Johnson & Johnson vaccine protects against the Delta variant. However, it is believed that the single-shot vaccine does offer protection against the variant. Dr. Scott Gottlieb, former Food and Drug Administration commissioner, reportedly said the Johnson & Johnson vaccine appears to be about 60% effective against the delta variant. Precise data on the efficacy of the Johnson & Johnson/Janssen vaccine, which requires only one dose, is still pending.

How to stay safe?

Getting vaccinated is the first and most important step, but it’s not the only one. Remember that even after immunization, you must adhere to all safety protocols with complacency.

Properly fitting masks covering the nose and mouth should be worn at all times in public. Double mask if you can. Use hand sanitizers and disinfectant wipes regularly.

Refrain from going to crowded places, and if you must, ensure social distancing. Avoid using cash, go for digital payments as far as possible. Don’t eat or drink in public places, as you’ll have to remove your mask.