The emergence of variants is linked to ongoing surges since infections give viruses the chance to mutate and spread.
Many variants of the coronavirus are circulating around the world, but scientists are primarily concerned about three. How many variants of the coronavirus are there?
There are many circulating around the world, but health experts are primarily concerned with the emergence of three. As a virus infects people, it can mutate as it makes copies of itself. Some mutations can be harmful to a virus, causing it to die out. Others can offer an advantage and help it spread.
“Not every mutation is created equal,” said Dr. Mary Petrone, who studies infectious diseases at Yale University. “The virus is going to get lucky now and again.”Monitoring variants is important because of the possibility that they could make vaccines and treatments less effective, or change the way they infect people.
A mutation early in the pandemic fueled the spread of the virus around the world, but there had been no notable changes since — until recently, said Ohio State University biologist Daniel Jones.
One of the three main variants experts are watching was discovered in the United Kingdom late last year and has been detected in dozens of countries since. Health officials initially said it didn’t seem to cause worse disease, but some newer information suggests it might — that remains unknown at the moment. It does appear to spread more easily, which could lead to more hospitalisations and deaths.
The variant might become dominant in the US by March, according to the Centers for Disease Control and Prevention. Other variants first detected in South Africa and in Brazil also appear more contagious, experts say.
Data so far suggests current vaccines should still protect against these variants, though there’s some concern their effectiveness may be slightly diminished. There is some evidence that some antibody treatments may be less effective against certain variants.
There are ways to adjust vaccines and treatments to maintain their effectiveness, said Dr. Anthony Fauci, the top US infectious disease expert.The emergence of variants is linked to ongoing surges since infections give viruses the chance to mutate and spread. It’s another reason experts stress the importance of mask wearing and social distancing.
“The fewer humans carrying the virus, the fewer opportunities it has to mutate,” Jones said.The announcement that the coronavirus strain sweeping Britain could be more deadly as well as more transmissible has raised fresh concerns about the variant that has spread to dozens of countries.
Initially British experts said that their evidence suggested the new strain circulating in the UK — one of several to have emerged internationally in recent months — was between 50 per cent and 70 per cent more transmissible.On Friday, however, the government said the new variant could also be 30-40 percent more deadly, although it stressed the assessment relied on sparse data.
What has changed?
In mid-January, two separate studies by London School of Hygiene and Tropical Medicine and Imperial College London were presented to Britain’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG).They linked data from people who tested positive for the virus in the community — rather than in hospital — with death data and found a roughly 30 percent increase in the risk of death associated with the new strain.
The groups used slightly different methods, but both matched people with the new variant to those with the older variants, taking into account other variables like age and location and controlling for hospitals being under pressure.Other studies by Exeter University and Public Health England also found higher deaths and both came up with even higher figures.
Based on these analyses, NERVTAG said there was “a realistic possibility” that infection with the new variant is associated with an increased risk of death compared with previously circulating variants.The increase in transmissibility associated to the variant was already causing alarm, because the more people the virus infects the more people will suffer serious illness and the risk of death.
“Unfortunately, it looks as if this virus might be both” more infectious and potentially more deadly, John Edmunds, a professor in LSHTM’s Centre for the Mathematical Modelling of Infectious Diseases, told a press briefing Monday”So it’s really a serious turn for the worse unfortunately,” he said.
How reliable are the findings?
Researchers said there were still uncertainties in the data and said the picture would become clearer in the next few weeks.Edmunds said the findings were “statistically significant”.But he said while the studies used information from those tested in the community, most people who die of Covid-19 go straight to hospital and are tested there.
Researchers do not yet have that hospital information.NERVTAG said this lag in data could be why the studies did not find evidence of an increase in hospitalisations of people with the new variant, which seems at odds with the findings of increased severity of disease.
It also said the mortality data used in the research only covers eight percent of the total deaths during the study period and said the results “may therefore not be representative of the total population”.
Why more deadly?
Researchers think it could be the same set of mutations that has made it more infectious — although all stress more study is needed.One mutation in particular increases the virus’ ability to latch on more strongly to human cells and NERVTAG head Peter Horby, an emerging infectious disease professor at Oxford University, said evidence suggests this means it could make it easier to become infected.
“If it’s then able to spread between cells much quicker within the lungs, that may increase the rate of disease and the rate of inflammation, which may then progress quicker than your body can respond to, so it could explain both characteristics of the virus,” he said.Bjorn Meyer, virologist at France’s Institut Pasteur, told AFP that the issue could be viral load.
“The virus might not have evolved to be more deadly as such, but it might have evolved to grow more or better, which could cause more damage in a patient overall,” he said.
Does this affect treatments?
Horby, who also leads the Recovery trial — which identified the steroid dexamethasone as effective for severely ill hospital patients — said there was “no evidence” that treatments would work less well. Anti inflammatories such as dexamethasone “should work equally as well because it’s not related to the virus, it is related to the host response”, he said.
Horby said overall improvements in therapies and treatments — including things like better strategies for hospital respiratory support — have brought down case fatality rates since the first wave and could even “offset any difference with this new variant”.
As for the vaccines, a preliminary study this month from Britain and the Netherlands found the variant would not be able to evade the protective effect of current vaccines. Pfizer/BioNTech and Moderna have also released early research suggesting their vaccines would still be effective against the strain.
Don’t viruses weaken as they spread?
Scientists have sought to challenge the belief that the virus will become get less virulent as it evolves to become more infectious. The virus that causes Covid-19 is already “very good at its job of getting transmitted” said Emma Hocroft, an epidemiologist at the University of Bern.
“So I don’t think that we can make this assumption that it wants to be less severe. I don’t want to downplay that it is severe for many people, but for the majority of people, it’s not severe,” she told AFP. She said the ability to transmit before it kills was “a really low bar”, citing diseases like measles and HIV that have remained as dangerous.
Graham Medley, a professor of Infectious Disease Modelling at the LSHTM, told the Monday press briefing that despite uncertainties in the new studies on the new variant in the UK, they should dispel the idea that it would become less virulent. “It’s certainly not the case that this is a more benign virus,” he said.
Professor Shane Crotty, Ph.D. explains recent coronavirus mutations and how they might impact COVID 19 vaccines and transmission. COVID-19 research of Prof. Crotty and his team was published Jan. 6, 2021, in the prestigious Journal Science: https://science.sciencemag.org/conten… Prof. Shane Crotty is a Professor at the La Jolla Institute for Immunology, Center for Infectious Disease and Vaccine Research, Crotty Lab. Prof. Crotty also has an academic appointment with the University of California San Diago. See his full bio here: https://www.lji.org/labs/crotty/#over… Prof. Crotty on Twitter: https://twitter.com/profshanecrotty Interviewer: Kyle Allred, Physician Assistant, Producer and Co-Founder of MedCram.com TOPICS DISCUSSED IN THIS VIDEO INCLUDE: 0:00 Intro 0:08 SARS-CoV-2 / COVID 19 mutations (UK variant etc.) and implications for COVID-19 vaccines 10:58 How to test if coronavirus variants can escape immunity 12:28 How have mutations made this virus more transmissible? 17:44 Could mutations make vaccines less than 50% effective? 24:15 Possible changes to vaccine schedules (one dose, half dose)? 35:34 Could alternate COVID-19 vaccine schedule make mutations more likely? 38:29 What is next for Prof. Crotty and his team? (This video was recorded on January 5, 2021) PREVIOUS DISCUSSION WITH PROF. CROTTY (Dec 16, 2020): https://youtu.be/eK0C5tFHze8 REFERENCES: Viral mutations may cause another ‘very, very bad’ COVID-19 wave, scientists warn (Science) | https://www.sciencemag.org/news/2021/… Vaccine Tracker (Bloomberg) | https://www.bloomberg.com/graphics/co… FDA Statement on Following the Auth. Dosing Schedules for COVID-19 Vaccines | https://www.fda.gov/news-events/press… S-variant SARS-CoV-2 is assoc. with sig. higher viral loads in samples tested by ThermoFisher TaqPath RT-QPCR (MedRxiv) | https://www.medrxiv.org/content/10.11… Human Leukocyte Antigen (HLA) System | https://www.merckmanuals.com/professi… UK reports new variant, termed VUI 202012/01 (GISAID) https://www.gisaid.org/references/gis… Covid-19 in South Africa: Scientists seek to understand new variant (BBC) | https://www.bbc.com/news/world-africa… Mutation Allows Coronavirus to Infect More Cells. Scientists Urge Caution (NY Times) | https://www.nytimes.com/2020/06/12/sc… The UK is delaying second vaccine shots and it’s proving controversial (CNBC) https://www.cnbc.com/2021/01/05/the-u… The receptor binding domain of the SARS-CoV-2 (News Medical Life Sciences) | https://www.news-medical.net/news/202… NY Times article highlighting Prof. Shane Crotty’s research: https://www.nytimes.com/2020/11/17/he… THE MEDCRAM WEBSITE: Visit us for videos on over 60 medical topics and CME / CEs for medical professionals: https://www.medcram.com SUBSCRIBE TO THE MEDCRAM YOUTUBE CHANNEL: https://www.youtube.com/user/MEDCRAMv… Get notified of new videos by hitting the bell icon! PREVIOUS / RECENT MEDCRAM COVID-19 INTERVIEWS: Vitamin D and COVID 19: The Evidence for Prevention and Treatment of Coronavirus (SARS CoV 2) with Professor Roger Seheult, MD https://youtu.be/ha2mLz-Xdpg At Home COVID 19 Antigen Testing and Vaccine Update with Professor Michael Mina, MD https://youtu.be/CjphzlV5DYo All coronavirus updates are at MedCram.com ad-free (including more videos on RNA vaccines, BioNTech vaccine, vaccine side effects, AstraZeneca Oxford coronavirus vaccine, new strain of coronavirus, and more): https://www.medcram.com/courses/coron… We offer over 60 medical topics (ECG Interpretation, DKA, influenza, measles, mechanical ventilation, etc.) on our website and CME for clinicians. MEDCRAM WORKS WITH MEDICAL PROGRAMS AND HOSPITALS: MedCram offers group discounts for students and a variety of medical programs, hospitals, and other institutions. Contact us at firstname.lastname@example.org if you are interested. MEDIA CONTACT: Media Contact: email@example.com Media contact info: https://www.medcram.com/pages/media-c… Video Produced by Kyle Allred FOLLOW US ON SOCIAL MEDIA: https://www.facebook.com/MedCramhttps://twitter.com/MedCramVideoshttps://www.instagram.com/medcram DISCLAIMER: MedCram medical videos are for medical education and exam preparation, and NOT intended to replace recommendations from your doctor. #COVID19#SARSCoV2#Coronavaccine