Virologist: New COVID-19 strains come from where things got out of hand

A social distancing sign at the icerink in Tallinn's Old Town.
A social distancing sign at the icerink in Tallinn's Old Town. Source: Helen Wright/ ERR

Recently, more and more reports on new strains of the coronavirus have come out, often connected to an accelerated spread of the novel coronavirus. ETV's current affairs show "AK.Nädal" took a look at which strains have been discovered in Estonia and how the virus' mutatins affect the development of vaccines.

While reproducing, the coronavirus constantly mutates, which has led to there being thousands of different variants of the virus worldwide. For example, the initial strain of the virus discovered in the spring of 2020, connected to the Chinese city of Wuhan, has not been found in Estonia for some time. Specialists are more worried about strains from the UK, South Africa and Brazil, that have been found to spread at a faster rate.

A laboratory in Tartu is the only establishment where strains discovered in Estonia are studied. Radko Avi, head of the KoroGeno-Est-2 project, said their goal is to research how the rate of the agressive strains has changed in Estonia and how many variants of the novel coronavirus have spread in Estonia.

To put it simply, the lab researchers deal with sequencing the virus using tests sent to them by Synlab, using the tests to determine the genomic sequence of DNA.

"We make certain the viral OGA protein gene of the virus; identifying any possible faster-spreading strains. We send this information to the Health Board (Terviseamet). The entire genomic sequence takes some more time to be ready," Avi said.

The scientists at the establishment can still not identify all virus strains, but rather analyze the strains brought into Estonia. In addition, the European Centre for Disease Prevention and Control (ECDC) is of help to Estonia and researchers send some 200 strains there weekly.

Strains and the effectiveness of vaccines

Irja Lutsar, virology professor at the University of Tartu and head of the government's scientific council, said that if it is necessary to identify strains among patients, the analysis would be conducted independently.

If the Health Board's task is to limit the spread of the more agressive strains, another topic is the effectiveness of vaccines. Current studies have shown that the existing vaccines work well against the UK variant. The South African one as well, but not as effectively.

"That the South African strain corresponds less well to the vaccine was shown in previous experiments. To my understanding, all pharmaceutical companies operating on the market are redesigning their vaccines and trying to create one that would work on these strains. If new strains come out, where it is clear that vaccines do not work, a booster dose in a year, two years or six months will be added," Lutsar said.

University of Tartu virologist Andres Merits said adjusting vaccines to the different mutations is not too difficult. The main problem is however proving that the redesigned vaccines are effective and safe.

"This is certainly faster than the initial testing phase, where all three phases were gone through in a somewhat different fashion. But we can think that this will be the braking factor. In other parts, it should not create problems, because i do not believe the virus could create mutant combinations that are not able to be treated with vaccines," Merits said.

More and more strains emerging

The faster spread of the UK and South African strains has been spotted by different studies, but there is no evidence that the strains will lead to a more severe disease or higher mortality. At the same time, there is not much research to give any fundamental conclusions. What is certain however is that there are more and more strains.

Researchers do not think it is impossible that an Estonian strain could eventually pop up, but it is not too likely. "It is no surprise that these new mutations are from South Africa, Brazil, Great Britain - meaning the places where there have been difficulties controlling the virus. There is no mutation that I know of coming from Singapore, China or Taiwan, where the spread of the virus is under strict control," Merits noted.

Irja Lutsar said the virus is constantly looking for new ways to survive. "It tries and tries and tries and eventually hits on one. The likeliness of there being vaccine-evasive strains certainly exists," she said.

While new virus strains can spread at a faster pace and try to get away from vaccines, researchers note that the same simple measures - wearing a mask and social distancing - still work for all strains and viral diseases.

It is however important to keep an eye on strains arriving in Estonia via travel from other countries. "By today (Sunday - ed), we have found 29 of the UK strain and one strain, where one dangerous mutation of the South African variant has been represented. It is likely not the South African strain, but we have found the mutation. We cannot say what the percentage is of all Estonian viruses. Studies, where we also do a random sample are in the plans. We will likely be able to say the percentage of all Estonian viruses then," said Radko Avi.

A masked Jaan Poska statue on Valentine's Day. Source: Siim Lõvi/ERR


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Editor: Kristjan Kallaste

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