Tag: 1/8/21

Categories : COVID UncategorizedTags :

Pfizer/BioNTech Vaccine Effective against SA and UK COVID Variants

On By ModernMedia

Amidst concerns that the SARS-CoV-2 virus might escape the protection of vaccines, initial results from new research shows that the Pfizer/BioNTech vaccine remains effective against the South African and UK COVID variants.

The new variants, which are much more transmissible, had created concern that due to mutations in their structure, they might not achieve the full protection of the current vaccines, especially in the SA variant.

However, this is a preliminary study that has not yet been through a peer review process, and the worrying E484K mutation in the South African strain which has been shown to reduce antibody recognition has not been tested on – that is still to be done.

Using blood samples from 20 individuals who had received the Pfizer/BioNTech vaccine, antibodies in the samples successfully defended against the virus variants. The results were made available on the bioRxiv site. Pfizer chief scientific officer Dr Philip Dormitzer said that “it was a very reassuring finding that at least this mutation, which was one of the ones people are most concerned about, does not seem to be a problem” for the vaccine.

However, should future mutations of SARS-CoV-2 achieve viral escape from the vaccines, the necessary adjustments to counter this could be made to the vaccines within a matter of weeks. Dormitzer said that this work was only the start “ongoing monitoring of virus changes to see if any of them might impact on vaccine coverage.”

Source: Medical Xpress

Categories : GeneticsTags :

Not Quite Mirror Images: DNA of Identical Twins Differs Slightly

On By ModernMedia

The popular depiction of identical twins is that they are exactly that – individuals from a single zygote that are identical because their DNA is identical. But new research has shown that there can be a surprisingly large amount of mutations that differentiate one twin from another.

Twin studies have been popular in identifying the genetic basis of traits and conditions, such as vulnerabilities to disease, as well as in psychological studies examining the effects of genetic “nature” versus environmental “nurture”.

Sequencing the DNA of 387 pairs of identical twins, along with their parents, children and spouses, scientists in Iceland were able to find small numbers of early mutations between twins.Identical twins have an average of about 5.2 mutations between them, but in 15%, there were as many as 100 mutations. Such a number of genetic mutations could influence height differences or susceptibility to cancer.

Jan Dumanski, a geneticist at Uppsala University in Sweden, who was not involved in the new paper, said of the results, “The implication is that we have to be very careful when we are using twins as a model” for discerning the influences of nature and nurture.

The study went beyond previous ones that had already discovered small mutations between twins, to include parents, spouses and children, enabling them to pinpoint mutations in two kinds of cell: those present in just one individual and those passed on to their children. In addition, they found mutations occuring before the zygote split into two embryos.

Study co-author Kari Stefansson, a geneticist at the University of Iceland and the company deCODE genetics, said that his team had discovered cases where pairs of twins had mutations that were present in all cells of one twin, but not found in the other twin at all. However, “sometimes the second twin may show the mutation in some cells, but not all cells,” he said.

Source: Medical Express

Journal information: Hakon Jonsson et al. Differences between germline genomes of monozygotic twins, Nature Genetics (2021). DOI: 10.1038/s41588-020-00755-1