Vaccination Rates below 90% Could Paradoxically Promote the Emergence of Resistant Variants

As the number of vaccinated people increases, the competitive advantage of resistant strains increases. According to a new study, the risk is at its highest when vaccination coverage reaches 60%, which is exactly the threshold currently reached in the US.

COVID-19 Pandemic

COVID-19 Pandemic

The whole world is hoping that mass vaccination will stop the COVID-19 epidemic. However, a resistant variant to the vaccine must not be allowed to emerge. Still, the risk of developing a resistant strain is greatest when a large proportion of the population is vaccinated, but at a rate that is not enough to ensure herd immunity, according to a new study published in Nature Scientific Reports.

Read Also: The Delta Variant of COVID-19 Is Just as Contagious as Chickenpox According to CDC Report

The researchers simulated the probability of a resistant strain in a population of 10 million over the next three years, taking into account the number of vaccinated people, the mutation rate of the virus, the rate of spread, and the successive “waves” of sharply increasing infections, followed by a decrease in new cases after restrictions are imposed (restrictions, closures, etc.). Not surprisingly, they concluded that rapid vaccination and low prevalence reduce the risk of a resistant variant emerging. However, the study also shows that the risk is highest when a large proportion of the population is vaccinated, but not enough to ensure herd immunity.

Selection pressure increases as vaccination coverage increases

When a large proportion of the population is vaccinated, especially the at-risk population (the elderly and sick), policymakers and individuals are tempted to revert to pre-pandemic guidelines and behaviors that can contribute to high levels of virus transmission. However, this is the most favorable time for the emergence of resistant variants because of the phenomenon of “selection pressure”: as the number of vaccinated people increases, the competitive advantage of vaccine-resistant strains increases. This is what has happened to the Delta variant: as the proportion of vaccinated people continued to increase, its infective capacity has had to increase tenfold to continue spreading at the same rate.

Read Also: Nightmare Scenario: Could the Current Poorly Implemented Vaccination Campaign Lead to More Deadly SARS-CoV-2 Strains

No Country has yet reached the 90% rate needed for herd immunity

The problem is that this 60% appears to be the ceiling rate that we see in most countries. No country in the world has yet managed to reach the threshold of 90% collective immunity. If the coronavirus epidemic, unfortunately, continues at this rate and herd immunity is not attained, it may be necessary to resort to compulsory vaccination.

The virus continues to circulate even among vaccinated populations

Last Friday, the US Centers for Disease Control and Prevention (CDC) warned that while the vaccine prevents the risk of serious illness, it does not completely prevent the risk of spreading the infection “because the immunity that is generated is not primarily mucosal” (it does not prevent the virus from developing in the nose). Therefore, the CDC recommended that even vaccinated persons should again wear a mask indoors.


Rates of SARS-CoV-2 transmission and vaccination impact the fate of vaccine-resistant strains

Articles you may like:

Diets High in Plant Proteins Protect Women from Dementia, Cardiovascular Disease, and Cancer

Drinking Too Much Coffee Can Reduce Brain Size, and Cause Dementia

A New Cause of Male Infertility Found: Spermatozoa Swimming in Circles

Possible Causes of the Sudden Fall In COVID-19 Infections in the UK and Europe

SARS-CoV-2 Transmissibility: Can You Really Catch COVID-19 through Flatulence (Farts)?

MIT: A Once a Month Contraceptive Pill Could Soon Become Reality

Moderna and Pfizer’s mRNA Vaccines Do Not Make Straight Men Gay

Researchers to Start Testing Male Contraceptive Gel

Gilmore Health News

Coronavirus: The Real and False Side Effects of COVID-19 Vaccines

Guillain-Barré Syndrome Observed after the First Dose of the AstraZeneca Vaccine


Genf20 Plus: Reviews, Cost, Benefits, Ingredients, Side Effects, and Testimonials




Want to Stay Informed?

Join the Gilmore Health News Newsletter!

Want to live your best life?

Get the Gilmore Health Weekly newsletter for health tips, wellness updates and more.

By clicking "Subscribe," I agree to the Gilmore Health and . I also agree to receive emails from Gilmore Health and I understand that I may opt out of Gilmore Health subscriptions at any time.