Covid Delta Variant and Why it’s Concerning
Recently the delta variant of covid 19 (b16172) has been spreading across the globe.
Is it more contagious will the vaccines work against it?
Is it a deadlier disease with worse symptoms? Today in this article I am going to get to these questions.
The delta variant first emerged in India and then it made its way to England to become the dominant strain there.
Does The Delta Variant Cause More Severe Disease?
Is the delta variant more pathogenic meaning is it more likely to cause worse disease? yes, in a study done in Scotland which was published in the lancet researchers showed that the risk of being hospitalized with the delta variant is double that of the alpha variant. In a study done in the UK from May 20th to June 7th, the researchers led by Stephen Riley looked at their data which suggested that the delta variant is about 60% more transmissible than the alpha which was the variant that was first identified in the UK which was more contagious than the original strain that was originally emerging from Wuhan the research team showed that with the delta variant there was a doubling time of 11 days in an estimated r or reproductive number of 1.44, and those younger than age 50 were two and a half times more likely to be infected compared to older people another study looked at whether vaccines monoclonal antibodies or antibodies derived from covid 19 survivors could neutralize the delta variants here are some of the takeaways from that study for one the data showed that the delta’s variant affinity for the ace2 receptor was slightly better compared with the original Wuhan strain. One of the delta’s mutations is in its receptor-binding domain and that’s what allows for this. This virus uses spike protein to bind to the ace2 receptor in the body it’s the key in the lock analogy the virus then fuses with the cell membrane this process relies on cleavage meaning enzymes on the cell membranes that cut that spike protein at two different sites which triggers the cell to then engulf this virus it’s the turning of the deadbolt if you will well guess what the delta variant is also better at doing there’s a second delta mutation at one of the cleavage sites better cleavage better reproduction another takeaway from the study is that the authors concluded that neutralization of both viruses is reduced when compared with the original Wuhan strain but there’s no evidence of widespread antibody escape they said the data did suggest that those previously infected with covid may be more susceptible to re-infection by the new delta variant also it looks like monoclonal antibody treatments are ineffective at treating the delta variant.
Are Vaccines Effective?
The big concern is vaccine escape meaning that the current vaccines will become far less effective as the virus evolves so far it hasn’t happened but eventually, we’ll need new vaccines for the variants likely a yearly thing the good news is that these vaccines are still protective against the delta variant. According to research released by public health England for the Pfizer vaccine after both doses, it was 88% effective in preventing symptomatic disease and 96% effective at preventing hospitalization for Oxford AstraZeneca vaccine if they had both shots it was 92% effective at preventing hospitalization if you only get one shot of either one of these vaccines the effectiveness is pretty low it’s around 30 to 40 percent so more studies will soon be available when it comes to the Moderna and the Johnson vaccines.
Delta Variant and its Different Symptoms
Now, talking about this delta variant having new symptoms and possibly more severe symptoms, the Zoe covet symptoms study is an ongoing UK-based study where people can enter their symptoms on an app which then gets analyzed by the researchers from this study he noted that covid is now acting differently it’s more like a bad cold especially in the younger population the number one symptom being headache and then other symptoms including sore throat, runny nose, and fever.