In Spain, the delta variant, discovered in India, is not yet officially an object of “concern” (VOC). According to the latest report from the Ministry of Health, it accounted for less than 1% of infections and was a "variant of interest" (VOI), the lower level of alert. But the sequencing is weeks late and some experts, supported by data from communities that provide more information, such as Catalonia, already assume that it will become dominant in a few weeks. What does this mean for the development of the epidemic in the country? Accurate predictions are difficult to make, but from the UK, where it has been expanding rapidly, some lessons can be drawn in dealing with the new SARS-CoV-2 mutations.
In the British country, the variant from India went from being testimonial to practically all infections in two months.
It is the “natural dynamics of the epidemic”, according to Clara Prats, a researcher in the computational biology and complex systems group at the Polytechnic University of Catalonia (UPC).
“New variants arrive and when one is more transmissible than the previous one, it replaces the other.
This is what happened back in the day with alpha [which was discovered in the UK], ”he explains.
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In Spain, this will happen in less than a month, according to the calculations of Álex Arenas, a data physicist at the Rovira i Virgili University, who has been running the entire pandemic using mathematical models to predict the spread of the virus. His estimate is based on the expansion in the United Kingdom together with the evolution of Catalonia, which has reported this week that 20% of new cases correspond to the delta variant. "In Spain the data are not so clear, but with this expansion in Catalonia it can be inferred that in mid-July it will be predominant," he stresses.
Although official statistics indicate that in Spain this new lineage accounts for less than 1% of infections, it is based on outdated figures, from case sequences that occurred three or four weeks ago. And the advance is exponential. In the United States, which declared the delta variant "of concern" this week, this variant accounted for 0.6% of cases in April, 1.3% at the beginning of May and 2.5% at the middle of that month. It is likely that there, too, it will become a majority in a few weeks.
All these data, together with those from the United Kingdom, make it quite clear that the variant is more transmissible, although as José Jiménez, researcher of emerging viruses in the Department of Infectious Diseases at King's College London, recalls, it is something that has to be confirmed in laboratory.
According to preliminary information, it also appears to be causing more hospitalizations.
“These are figures that evolve from week to week and sometimes give false impressions.
We have to wait for them to consolidate, but it seems that this is the case ”, adds Clara Prats.
Carrying out a covid test in Bombay (India) on June 17.
Rajanish Kakade / AP
In the same way, it does not seem more lethal and, as far as is known, two doses of the vaccines are practically as effective against this variant as against alpha. What preliminary studies from the United Kingdom have revealed is that it responds worse to a single dose, which avoids a high percentage of hospitalizations, but not so much of symptomatic infections: 30% of them, compared to 50% in the variant alpha.
This may be one of the reasons why cases have been growing for almost a month in the United Kingdom, which has had to suspend its de-escalation for four weeks to prevent the epidemic from getting out of control. Its health authorities followed the strategy of vaccinating mainly with first doses to protect, even partially, as many people as possible, and relegated the second puncture to later. This plan went very well in principle: cases fell rapidly and allowed the lifting of numerous restrictions. But with the delta variant it has turned against him and now the authorities are doing their best to complete the pattern in all those who received an inoculation.
Spain followed the opposite strategy and is one of the European countries with the most second doses administered. However, among those over 60, who have received AstraZeneca, the second injection progresses very slowly: less than a third are fully immunized. Although the technical sheet allows completing the schedule in three weeks, the Spanish strategy has chosen to speed up the deadlines and take it until 12, preferably. Communities such as Madrid and Catalonia are already shortening this interval to protect this population, which, as Prats points out, is right now the most vulnerable.
In the opinion of Federico Martinon, pediatrician and advisor on vaccines at the World Health Organization, second doses should be prioritized in this range.
Of the five million people who have received an AstraZeneca injection, only one million have completed their immunization.
In the warehouses of the autonomous communities there are 1.7 million doses of this drug unused, which would give some margin to accelerate the process.
The problem comes from the fact that the irregularity of the arrivals does not allow knowing when more will be received, or in what quantities.
Vaccination with AstraZeneca at the Wanda Metropolitan in Madrid on May 17 Samuel Sánchez
In the United Kingdom, in addition, the delta variant is showing symptoms other than those that have been associated with covid.
In addition to coughing and shortness of breath, patients are reporting a runny nose, something that was not characteristic of the other variants.
Although data remains to be confirmed, Arenas warns that the population has to protect itself when it notices "a simple cold."
Will a new wave arrive with the delta variant in Spain?
The experts consulted are cautious when making predictions about how the delta variant may affect Spain. Jiménez points out that the situation of each country, the different restriction measures imposed and the behavior of the people must be taken into account. “This is something we have seen with the alpha variant, which in some places was said to be more contagious and more lethal based on what we saw in the UK in the previous wave. However, and fortunately, this has not been the case when it has been imposed in other countries such as Spain, where it has become the dominant variant, but hospitals have not collapsed at the level that we have seen in the United Kingdom ”, he explains .
Prats argues that at the point of vaccination coverage that we are "there is a lot of cattle, but not everything." This expert believes that the variant can increase the cases or simply stop the decline that has been taking place in Spain since the end of April. That will depend, to a large extent, on how citizens behave. “The thing to avoid as much as possible is the proliferation of supercontagion events. We could sustain a soft growth, but a fast one would be unsustainable with the measures that exist now ”, he points out. This can occur in "risky situations with many people in closed places without ventilation, or masks or distance." “You get 50 infections that are amplified at homes. If this is punctual, nothing happens, but if it becomes systematic it would be a problem ”, he adds.
Faced with these risks, there are countries that are already acting.
The German health authorities have asked for "maximum caution" and since May 23 they closed their borders to the British, reports
Elena G. Sevillano
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In Portugal, the government has closed Lisbon and has prohibited leaving and entering the capital during the weekend.
Spain at the moment has not taken special measures for this variant and continues to allow travelers from the United Kingdom to arrive.
In his last appearance, last Monday, Fernando Simón, director of the Center for the Coordination of Health Alerts and Emergencies, assured that at the moment there are only “testimonial cases”.
“It is possible that little by little it will occupy a space.
I do not think it has a significant impact, that it could, but we should not alert more than necessary when it is not necessary, "he said.
