Vaccine-immune Corona variants conceivable say researchers

According to the information, such escape variants can arise if the virus spreads in a population with incomplete immune protection. This is also the case, for example, if the immunity slowly decreases after surviving an infection or vaccination.

In a population with a certain degree of immunity, escape variants would have an advantage over the original virus with comparable infectivity, explained Pöhlmann and Hoffmann. In such a scenario, an escape variant would become dominant relatively quickly. An example could be the mutant P.1 in Brazil.

“If there is hardly any immunity in a population, as is currently the case in Germany, an escape variant would be in direct competition with the predominant virus variants, which in turn still find enough susceptible hosts,” the scientists explained.

Then an escape variant would only prevail over a large area if it was also easier to transfer.

The experts from the German Primate Center, together with colleagues from the Ulm University Hospital, discovered that an antibody used for Covid-19 therapy was completely ineffective in variants B.1.351 (South Africa) and P.1. They are classified as escape variants. It can be assumed, however, that B.1.351 and P.1 would still be inhibited by the available vaccines.

“However, the vaccination protection may be reduced and of shorter duration.”

It is therefore all the more important to quickly achieve large-scale immunity in the population through vaccination and thus deprive the host variants that they need to spread, they argued.

In order to improve the protection against variants such as B.1.351 and P.1, the existing vaccines could be adapted. “This procedure would be similar to the vaccination strategy with which we protect ourselves against flu viruses,” explained Pöhlmann and Hoffmann.

The emergence of variants that are no longer inhibited by vaccines that are now available is “an extreme scenario, but cannot be ruled out”. In order to reduce the likelihood that escape variants will arise, the spread of the virus must be effectively contained – for example by complying with the AHA rules and vaccination across the board.

The researchers echoed the concerns of French epidemiologist Professor Didier Raoult, who has warned of the emergence of variants especially as a result of mink breeding since these animals are highly susceptible to the Coronavirus, which spreads rapidly to humans – the most likely initial source of infection. Both Denmark and Sweden have suspended mink farming after outbreaks of Covid-19.

Retrouvez mon bulletin hebdomadaire : aux origines des variants. Je reviens notamment sur les motifs de mon séjour au Sénégal, la semaine dernière.https://t.co/FuZBKwtZwW

— Didier Raoult (@raoult_didier) April 9, 2021

As of January 2021, the virus had been found at 400 mink farms in at least eight countries in the EU and European Economic Area – 290 in Denmark, 69 in the Netherlands, 17 in Greece, 13 in Sweden, three in Spain, two in Lithuania and one each in France and Italy. In France, the region of Brittany has been affected by a variant associated with these animals.

In March, French health authorities warned against this variant after eight infected patients died, ARS Bretagne announced.

In a press release, the Directorate General of Health specified that its discovery was made as part of the monitoring of the cluster at Lannion hospital, in Côtes-d’Armor. “On March 13, 79 cases were identified, including 8 cases carrying the variant, confirmed by sequencing”.

The variant was placed in the VUI (Variant Under Investigation) category of the World Health Organization (WHO) because nasopharyngeal tests do not detect it. Indeed, the PCR tests corresponding to the 8 carriers of the variant were all negative. To detect it, healthcare professionals had to use serological tests or deep breathing samples.

At the end of last month, the prefect of Brittany and the local ARS announced that the 8 patient carriers had died. However, they “have not yet established the link between the variant and their deaths”.

Pierre Tattevin, head of the infectious diseases department at Rennes University Hospital, has alluded to “dozens of cases” and “deaths” on BFM TV due to the difficulty of carrying out the follow-up and the tracing of the positive cases: “The PCR tests are negative […] because the patients do not excrete it at the level of the nose, since when one takes deeper samples – for example when the patients are in intensive care and need lung samples, at that time the test is positive.”

In his weekly bulletin on YouTube, Raoult also urged regulators to ban Remdesivir as a treatment for Covid because it acts as a variant multiplier.