Delta variant of the coronavirus: the key to its control lies in mass vaccination

There is an intense global conversation about the Delta coronavirus variant. This variant was initially discovered in India and quickly spread to over 80 countries, including the Latin American region. On June 15, Delta was reclassified by the United States Centers for Disease Control and Prevention (CDC). It went from “variant of interest” to “variant of concern”.

The “worrying” variants are those in which, among other things, there is evidence of a greater capacity for contagion and produces more severe disease. For example, they produce more hospitalizations or deaths. They are less neutralized by the antibodies generated during a natural infection or by a previous vaccination.

When variants of ‘concern’ are detected, firm public health actions are needed, such as notifying the World Health Organization (WHO) and CDC, of ​​local or regional efforts to control the spread and development. new vaccines or diagnostic tests.

The Delta variant is responsible for over 90% of COVID-19 cases in the UK, and as of June 13, it has been found in 10.3% of COVID-19 cases in the United States. The main feature of the Delta variant: it is 40-60% more contagious than the Alpha variant, first discovered in the UK.

The Alpha variant was 40% more contagious than the original version of the novel coronavirus. It can be deduced that the Delta variant is twice as contagious as the original coronavirus.

Regarding the type of disease that the Delta variant produces, According to a study in China, up to 12% of infected patients become seriously or seriously ill within three to four days of onset of symptoms. In comparison, last year and with the original variant, only 2 or 3% of patients were aggravated in the first days by the disease, sometimes it reached 10%.

On the other hand, a study published by Scottish researchers in The Lancet June 14 revealed that People infected with the Delta variant are twice as likely to be hospitalized compared to those who are hospitalized with the Alpha variant. The study failed to analyze complications or mortality in affected patients.

Britain’s Prime Minister Boris Johnson has postponed the easing of restrictive measures in the country for a month. They were due to start on June 21, but they were postponed due to concerns over the unusual increase in cases and hospitalizations caused by the Delta variant.

Meanwhile, more information is known about the vaccines authorized so far. A single dose of the messenger RNA vaccine, manufactured by Pfizer and BioNTech, gave only 33% protection against the Delta variant. But when the second dose was given, the protection increased to 79%. This is slightly less than the 92% protection given by the same vaccine against the Alpha variant.

Another study by the UK Public Health Agency found that two doses of the Pfizer / BioNTech vaccine are 96% effective in preventing hospitalizations. In summary, the key to controlling the Delta variant of the coronavirus lies in mass vaccination of the population.

With regard to vaccines, there are other developments. In a press release, It was announced that the Novavax study, which was conducted on 30,000 volunteers from Mexico and the United States, showed the vaccine to be 90.4% effective in preventing symptomatic illnesses.

What is interesting is that the Novavax vaccine uses a completely different platform from all the vaccines currently in use. This is called ‘recombinant nanoparticle technology’, and it uses a defense system stimulant, ‘Matrix M’, which It originates from an extract from the bark of a tree that grows in Chile, called quillay.

This recombinant nanoparticle technology is already used in the hepatitis B vaccine, the human papillomavirus (HPV) vaccine and some influenza vaccines. You start by isolating the gene that codes for the coronavirus spike protein. The gene is introduced into an aculovirus and allowed to infect moth cells which begin to produce spike proteins which are isolated and clustered into nanoparticles. The vaccine is prepared with nanoparticles containing proteins with quillai resins. Novavax plans to seek emergency use authorization from the US FDA and plans to produce 100 million doses per month by the third quarter of this year.

In the case of Germany’s Curevac messenger RNA vaccine, an interim review of its Phase 3 studies has been disappointing. It was only 47% effective in preventing COVID-19 disease. This is less than the 50% WHO needs for its vaccine to be accepted. It is striking that a vaccine which uses the same technology as those of the companies Pfizer / BioNTech and Moderna had these results. It is possible that certain details in the preparation of the vaccine could explain the difference.

While COVID-19 cases and deaths have declined in the United States, the threat of the Delta variant remains active. A few days ago at the White House, Anthony Fauci, director of the National Institute of Infectious Diseases, said that the Delta variant was circulating in the United States at a rate similar to that of England and encouraged everyone world to get vaccinated against COVID-19.

Coronavirus Podcast Material: Fact vs Fiction, with Dr. Elmer Huerta, by CNN

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