Will COVID-19 vaccines need to be adapted regularly?

Newswise — Influenza vaccines need to be evaluated every year to ensure they remain effective against new influenza viruses. Will the same apply to COVID-19 vaccines? In order to gauge whether and to what extent this may be necessary, a team of researchers from Charité - Universitätsmedizin Berlin compared the evolution of endemic 'common cold' coronaviruses with that of influenza viruses. The researchers predict that, while the pandemic is ongoing, vaccines will need to undergo regular updates. A few years into the post-pandemic period, however, vaccines are likely to remain effective for longer. This study has been published in Virus Evolution*.

Influenza viruses are masters at evading the human immune system. They undergo such rapid changes that antibodies produced by the immune system in response to a previous infection or vaccination become unable to neutralize them. This is why the complex task of evaluating and updating the seasonal influenza vaccine has to be repeated every year. Mutations within SARS-CoV-2 have already produced a number of variants, some of which (such as the South African variant) partially evade the body's immune response. As a result, some vaccine manufacturers have already started to develop new versions of their vaccines. What does this mean for the future? Will COVID-19 vaccines mirror influenza vaccines in requiring regular updates?

In order to gauge whether, over the long term, SARS-CoV-2 is likely to demonstrate an immune evasion capability on par with that of influenza viruses, Charité virologists have studied the genetic evolution of the four currently known 'common cold' coronaviruses. These relatively harmless coronaviruses are known to be responsible for approximately 10 percent of common colds in the world and have been in circulation in humans significantly longer than SARS-CoV-2. Just like SARS-CoV-2, they enter human cells using the 'spike protein', a surface protein which gives the virus its characteristic crown-like appearance (and name). The spike protein also forms the target of all current COVID-19 vaccines.

For their study, the researchers focused on the two longest-known coronaviruses (termed 229E and OC43), tracing changes in the spike gene approximately 40 years into the past. The researchers started by comparing sequences from a range of old samples which had been deposited in a genetic sequence data bank. Based on the mutations which had emerged over time, they then produced phylogenetic trees for both coronaviruses. The researchers compared their findings with the phylogenetic tree of H3N2, an influenza subtype which is particularly effective at evading the human immune response.

The researchers' calculations revealed one feature which was common to the phylogenetic reconstructions of both the coronaviruses and the influenza virus: all three had a pronounced ladder-like shape. "An asymmetrical tree of this kind likely results from the repeated replacement of one circulating virus variant by another which carried a fitness advantage," explains the study's first author, Dr. Wendy K. Jó from Charité's Institute of Virology. "This is evidence of 'antigenic drift', a continuous process involving changes to surface structures which enable viruses to evade the human immune response. It means that these endemic coronaviruses also evade the immune system, just like the influenza virus. However, one also has to look at the speed with which this evolutionary adaptation happens."

For this step, the researchers determined the three viruses' evolutionary rates. While the influenza virus accumulated 25 mutations per 10,000 nucleotides (genetic building blocks) per year, the coronaviruses accumulated approximately 6 such mutations in the same timeframe. The rate of change of the endemic coronaviruses was therefore four times slower than that of the influenza virus. "As far as SARS-CoV-2 is concerned, this is good news," summarizes Prof. Dr. Christian Drosten, Director of the Institute of Virology and a researcher at the German Center for Infection Research (DZIF).

SARS-CoV-2 is currently estimated to change at a rate of approximately 10 mutations per 10,000 nucleotides per year, meaning the speed at which it evolves is substantially higher than that of the endemic coronaviruses. "This rapid genetic change in SARS-CoV-2 is reflected in the emergence of numerous virus variants across the globe," explains study lead Prof. Dr. Jan Felix Drexler, a researcher at both the Institute of Virology and the DZIF. "This, however, is likely due to the high rates of infection seen during the pandemic. When infection numbers are so high, a virus is able to evolve more rapidly. Based on the rates of evolution seen in the endemic common cold coronaviruses, we expect that SARS-CoV-2 will start to change more slowly once infections start to die down - meaning once a large proportion of the global population has developed immunity either as a result of infection or through vaccination. We expect therefore that COVID-19 vaccines will need to be monitored regularly throughout the pandemic and updated where necessary. Once the situation has stabilized, vaccines are likely to remain effective for longer."

*Jo WK et al. The evolutionary dynamics of endemic human coronaviruses. Vir Evol 2021. doi: 10.1093/ve/veab020

###

SEE ORIGINAL STUDY




Filters close

Showing results

110 of 5625
Released: 12-May-2021 5:10 PM EDT
Understanding SARS-COV-2 proteins is key to improve therapeutic options for COVID-19
Bentham Science Publishers

COVID-19 has had a significant impact since the pandemic was declared by WHO in 2020, with over 3 million deaths and counting, Researchers and medical teams have been hard at work at developing strategies to control the spread of the infection, caused by SARS-COV-2 virus and treat affected patients.

Newswise: 264700_web.jpg
Released: 12-May-2021 4:55 PM EDT
COVID-19 vaccine does not damage the placenta in pregnancy
Northwestern University

A new Northwestern Medicine study of placentas from patients who received the COVID-19 vaccine during pregnancy found no evidence of injury, adding to the growing literature that COVID-19 vaccines are safe in pregnancy.

Released: 12-May-2021 3:45 PM EDT
Parks not only safe, but essential during the pandemic
Drexel University

Parks played an important role for people seeking respite from the toll of social isolation during the pandemic, and according to new research from Drexel University, they did so without increasing the spread of COVID-19.

access_time Embargo lifts in 2 days
Embargo will expire: 18-May-2021 11:00 AM EDT Released to reporters: 12-May-2021 3:35 PM EDT

A reporter's PressPass is required to access this story until the embargo expires on 18-May-2021 11:00 AM EDT The Newswise PressPass gives verified journalists access to embargoed stories. Please log in to complete a presspass application. If you have not yet registered, please Register. When you fill out the registration form, please identify yourself as a reporter in order to advance to the presspass application form.

Newswise: Pandemic Has 'Severely Weakened Surgical Innovation Pipeline'
Released: 12-May-2021 3:15 PM EDT
Pandemic Has 'Severely Weakened Surgical Innovation Pipeline'
Johns Hopkins University Carey Business School

In a new study for the journal Surgical Innovation, Associate Professor Toby Gordon of the Johns Hopkins Carey Business School addresses the ways in which COVID-19 has slowed medical innovation.

Released: 12-May-2021 2:55 PM EDT
Mental health helplines need human-centered solutions
Cornell University

In India today, dozens of phone numbers are available for people who are having a severe mental health emergency. Oftentimes, however, callers experience difficulty in getting connected with someone who will listen to them; sometimes the phone will just ring and ring.

Newswise: Weizmann Institute Scientists Reveal the Triple Threat of Coronavirus
Released: 12-May-2021 2:40 PM EDT
Weizmann Institute Scientists Reveal the Triple Threat of Coronavirus
Weizmann Institute of Science

Scientists at the Weizmann Institute and the Israel Institute for Biological, Chemical and Environmental Sciences took a novel tack to investigating SARS-CoV-2’s powerful ability to infect, finding that the virus deploys an apparently unique three-pronged strategy to take over the cell’s protein-synthesis abilities. The work could help develop effective Covid-19 treatments.

Newswise: Rush Collaborates With Malcolm X College to Train COVID-19 Vaccine Ambassadors
Released: 12-May-2021 2:20 PM EDT
Rush Collaborates With Malcolm X College to Train COVID-19 Vaccine Ambassadors
Rush University Medical Center

Rush staff members collaborated with Malcom X College to provide content including video scenarios and conversation advice, for a new Vaccine Ambassador Course offered to the public.

Newswise: Using Ultrasound Stimulation to Reduce Inflammation in COVID-19 In-Patients
Released: 12-May-2021 1:35 PM EDT
Using Ultrasound Stimulation to Reduce Inflammation in COVID-19 In-Patients
University of California San Diego Health

Researchers at UC San Diego School of Medicine have begun a pilot clinical trial to test the efficacy of using ultrasound to stimulate the spleen and reduce COVID-19-related inflammation, decreasing the length of hospital stays.

Released: 12-May-2021 9:00 AM EDT
Rapid COVID-19 Diagnostic Test Delivers Results Within 4 Minutes With 90 Percent Accuracy
Perelman School of Medicine at the University of Pennsylvania

A low-cost, rapid diagnostic test for COVID-19 developed by Penn Medicine provides COVID-19 results within four minutes with 90 percent accuracy. A paper published this week in Matter details the fast and inexpensive diagnostic test, called RAPID 1.0. Compared to existing methods for COVID-19 detection, RAPID is inexpensive and highly scalable, allowing the production of millions of units per week.


Showing results

110 of 5625

close
1.09517