Covid-19: What makes the Delta coronavirus variant, first found in India, so concerning? | India News
- What sets the delta variant apart from other variants and what makes it so concerning?
The delta variant of Sars-Cov-2, also known as B.1.617.2, is a variant of concern like others we’ve seen before, including “alpha” (first found in the UK), “beta” ( first identified in South Africa) and “gamma” (discovered in Brazil). Two factors distinguish delta and make it potentially the most dangerous to date: First, it has an approximately 40% higher transmission rate compared to alpha, which already had a 50% higher transmissibility than the original strain. of the virus. This is clearly visible in the data from the UK, which shows that the delta variant went from representing 1% of all cases in early April to 70% in mid-May. It is likely to almost completely replace the alpha variant by the end of June. The increased transmissibility is also apparent from the increase in the number of cases in the UK. Second, it is also believed to cause more serious disease than alpha, resulting in a further increase in the percentage of positive cases requiring hospitalization, even though infections are found in younger people. This second most serious problem has not been confirmed with any other variant to date.
- Does the delta variant respond to vaccines? Is there any information on which vaccines may work best against you?
What is quite surprising about delta is that it has lost the key mutation that had people worried about the beta and gamma variants (to be technical, it is the one at position 484 of the amino acid chain of the virus peak protein ). This is one of the mutations that contributed to the loss of response to some antibodies, including those produced by vaccines. We know that delta is less sensitive than alpha to vaccine-generated antibodies, and about the same level as beta. Additionally, data from Public Health England shows that the first dose of the Pfizer Inc.-BioNTech SE and AstraZeneca Plc vaccines provide only about 30% protection against delta, although this increases to at least 88% after the second dose of the Pfizer vaccine. and 60% after the second dose of Astra vaccine (likely to increase with more time for second doses to take effect in Great Britain). These levels of protection are lower than those seen against older variants, such as alpha, but still show that two doses of vaccines work quite well against the delta variant. The real risk is when considering the general population, where many people are not vaccinated or have only one dose of the vaccine, combined with the increased transmissibility and severity of delta disease.
- Where is it in the world?
This is not an easy question to answer because the level of genomic surveillance is low in many countries. According to data from GISAID, a global effort to share and track virus information, the UK has the highest proportion of the delta variant outside of India, with 70% of its cases. The United States is showing around 5% (and growing) and Germany is around 2%. Italy and Spain are each at around 3% to 5%. The problem is that many of these countries are on the path of opening up their economies, while their full vaccination levels have not yet reached the critical 50% to 70% required to control the spread of the virus.
- Should the United States or the countries of the European Union care about this as much as the United Kingdom?
The spread of the delta is already out of control in the UK. But other countries seem to be only in the early stages. I think the best any country, where the virus variant is already present, can do is to vaccinate as quickly as possible, while increasing genomic testing and surveillance. Otherwise, the first indication of a problem will be a higher rate of positive cases. The UK’s situation compared to Israel sheds light on why the delta variant is a problem. Israel managed to control its cases when it reached a vaccination rate of 50% among its entire population. Despite the UK achieving a 42.3% vaccination rate, the case count has started to rise rapidly in the last two weeks due to a combination of early reopening and the spread of the delta. And by the way, the vaccination rate in the US is similar to that in the UK, so there are risks there too.
- Why is the UK sending military to the worst affected regions? Scare people and cause social distancing? Or can the military do something with delta that normal healthcare professionals can’t?
I have to assume this is about getting as many people tested as possible, which requires shoes or boots on the ground. With sufficient testing and an increase in vaccines at hotspots, the spread can be better controlled, allowing the government to remove all restrictions. However, not only do I believe that the June 21 relaxation of all restrictions will have to be delayed, it is also possible that some earlier relaxation steps, such as allowing eating indoors, will need to be reversed to stop the spread of the delta.
- Much of the attention has been focused on the UK, but the greatest danger from the most communicable variants is to the many parts of the world where vaccination rates are very low, right?
Absolutely. If you summarize everything I mentioned above, especially the effectiveness of delta vaccines, the best solution, in addition to severe blockage, is to test, isolate positive cases, and vaccinate.
- Can the virus mutate again to get even worse?
Oh sure, and it almost certainly has already. Many mutations do nothing or really hamper the virus. However, in the case of delta, high levels of transmission combined with a partially vaccinated population increase the risk of more people contracting the virus and increase the risk of additional significant mutations that could drive delta to further evade induced immunity. by the vaccine. As of now, the depth of the vaccine-induced immune response to the virus is strong enough that those who are fully vaccinated are much less likely to develop serious illness. But that still leaves a whole swath of the population at risk. That’s why I cringe when I hear that 30% of American adults don’t want to get vaccinated.
- What does it mean for parents of children and young adults who are not yet eligible for vaccination? Should they keep you tied up this summer? Cancel long-distance trips?
So far, children have had a much lower risk of developing severe Covid-19 disease, although that doesn’t mean they are completely risk-free. As for adolescents, the vaccine is already available. But for those who cannot take it or do not have access, there should be continued use of non-pharmaceutical preventive methods, such as masking and distancing, until community cases are so low that the risk of contracting the virus is minimal. . In addition, we may need to reconsider our risk assessments for children if the delta variant or some derivative of it or others turn out to be worse for children. We already know that more young people are hospitalized with the delta variant in the UK than with previous variants. So far, the Sars-Cov-2 virus has been one step ahead of us. We need to regain the initiative, which is only possible with high levels of vaccination and continuous testing.