A highly infectious, new strain of COVID-19 called the Delta variant is raising alarm all over the world. So, what do we know about this?

The Delta variant, scientifically termed as B.1.617.2, contains mutations from two separate variants.

It was declared as a variant of global concern in May by the World Health Organization. It is 40-50 percent more transmissible than the Alpha strain identified in the UK.

This strain was found to be the primary reason behind India’s dangerous second wave of the coronavirus.

Now, it is causing a concern in the UK, where it comprises 91 percent of the new cases. It also makes up more than 10 percent of new cases in the US. It has also spread to at least 74 countries worldwide.

Chief Scientist at the World Health Organization, Soumya Swaminathan said that the Delta variant is becoming the globally dominant variant.

Meanwhile, the Delta variant, the UK’s most widely established COVID strain, could be behind more people reporting cold-like symptoms.

Fever, cough and loss of smell or taste are the classic COVID symptoms. However, with the Delta variant, a cough appears to be the fifth most common symptom, and the loss of smell doesn’t make the top 10.

Several studies suggest that the Delta variant seems to have stronger resistance to vaccines than other variants do. But there's also evidence that Covid shots are working against it.

The team behind the Sputnik vaccine meanwhile tweeted that theirs was "more efficient against the Delta variant... than any other vaccine. But they haven't published results yet. Early study shows Covaxin also offers protection against Delta.

The Delta variant has now acquired the K417N spike mutation – to form the ‘Delta Plus’ or AY.1 variant and is presently classified as a 'variant of concern' in India.

Experts say there is no cause for concern as of now in India since its frequency is not much. But the Centre has asked states to take immediate steps to contain the spread, increase testing and vaccination in areas that are seeing a rise in number of cases.