Delta variant of the coronavirus, 5 things to know


More contagious and probably more lethal, widespread in the United Kingdom, it now affects almost one in 4 cases in Italy. What we know and do not know about the diffusion and efficacy of vaccines

(Photo: Gerd Altmann via Pixabay)

The delta variant (formerly Indian) of coronavirus continue to to be talked about. Today we have more information, not least because the new viral form is more widespread, even if we do not yet know many aspects that concern it. The delta variant is certainly more transmissible and for this reason it is important to undergo the vaccination with both doses, since only one is not sufficiently protective. In Italy today it hits almost 1 in 4 people among those that test positive for coronavirus. What we know in 5 points.

1. The delta is more transmissible. But the ways of contagion are the same

The delta variant is more contagious, 40% to 60%, compared to the alpha (former English variant), which in turn was more transmissible than the traditional form of the virus. The World Health Organization (WHO) has defined the delta “very fast “ e “the most fit “, therefore more able to spread. For this reason, the greater contagiousness certainly plays a role in the evident growth of cases: in Europe they increased by 10% in the last week of June. However, there is currently no evidence that some transmission routes – think for example of infection via aerosols, from airborne virus particles – have a different weight than before.

2. It would be even more lethal: that’s why according to the WHO

When we talk about new, more contagious variants, we wonder if they are even more lethal, that is, associated with a greater number of severe forms and deaths. The other question then concerns the reasons: are they more lethal because they are more contagious (so we have more cases and inevitably more deaths) or because even in equal cases the disease is still more serious? The question also arose in the case of the English variant (alpha), which was more lethal, although the underlying causes have not been fully clarified. In the case of the delta, the WHO indicates that the variant “it could be more lethal Why it is more efficient in the way it is transmitted between people “, as he points out Mike Ryan, executive director of the WHO health emergencies program, adding that the variant “It can affect vulnerable people who can develop severe forms”.

3. How widespread it is

According to data from the end of June 2021 the delta variant is prevalent in UK, where it represents the 99% of cases. In Italy the latest estimates early July indicated a spread of 22.7% and it is possible that the infections associated with this particular viral form are still rising, both in Italy and in other European countries. The delta is destined to become prevalent in the old continent: in the last week of June the European Center for Disease Prevention and Control (Ecdc) indicated that by the end of the summer this variant it will cover 90% of new cases in Europe. And according to the WHO, which included it among the five variants “that cause concern “, is destined to become prevalent worldwide.

4. What are the frequent symptoms

International authorities are also studying the symptoms associated with the delta variant and the course of the disease, which may be slightly different than those of the traditional virus. So far the five most common classic symptoms indicated were: temperature, dry cough e exhaustion, together (in a smaller number of cases) with headaches, muscle aches, loss of smell and taste, and others. Today they also appear among the demonstrations, as shown by the Zoe Covid Study, a runny nose (cold), headache and sore throat more frequently. While the loss of smell decreases and is less widespread.

5. Are vaccines less effective against delta?

The European Medicines Agency (Ema) has announced that two doses of all available vaccines (and also the single dose of Johnson & Johnson’s single dose) are effective even against the delta variant, while the single dose would not be enough. However, latest news coming from Israel have attracted the attention of many. Israeli authorities have announced a possible 30% drop in the overall efficacy of delta vaccines, although unpublished data is yet to be confirmed. But in any case it must be emphasized that efficacy against severe forms remains high, again according to the Israeli survey, and equal to 93%. A result that confirms the importance of vaccination with two doses.


Categories:   Science

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