New variant likely won’t affect vaccine efficacy

• New variant will likely be detected soon in U.S.
• It may be more contagious but isn’t more virulent

The new COVID-19 variant identified in the United Kingdom is not predicted to change the efficacy of the vaccine, report Northwestern Medicine experts. 

So far, the variant only seems to transmit better, with no evidence of higher virulence, they said.  

“There’s no reason to get scared or panic, we just need to closely monitor this variant,” said Ramon Lorenzo, a Northwestern scientist who studies COVID-19.

The new variant’s presence might be detected soon in the U.S., as it has already been observed in other countries.

Northwestern experts can discuss:

• Variant’s contagiousness and virulence
• Likely impact on COVID-19 vaccines
• Whether variant will reach U.S.
• How to protect yourself from it
• Genetics of the variant known so far 
• What a genetic variant means

The experts are: 

Ramón Lorenzo is a research assistant professor in infectious diseases at Northwestern University Feinberg School of Medicine. He studies viral evolution and the interaction between viruses and the host during infection. Lorenzo has led multiple studies on SARS-CoV2 evolution and population dynamics and continues to study this new virus, including studies on viral population dynamics, intra-host evolution and public health.

Dr. Michael Ison is a professor of infectious diseases at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. Ison is conducting clinical trials in COVID-19 treatment and vaccines at Northwestern Medicine.

Dr. Marc Sala is an assistant professor of pulmonary and critical care at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. 

How soon before this variant makes it to the U.S.? 

Lorenzo: “The variant might already be present here and observed soon. That’s due to the number of patients that have been infected by this variant, the increase observed in November and the high connectivity between U.S. and U.K. It has already been detected in other countries. If the variant is observed in the U.S., it will indicate transmission events with the new U.K. variant, probably through travelling. 

“So far, there is no evidence of higher virulence, so no reason to get scared or panic. Also, this stresses the importance of molecular surveillance to anticipate the spread of new variants for SARS-CoV2 and other pathogens.”

Dr. Marc Sala: “The time frame of the variant’s depends entirely on human behavior, including government-imposed travel restrictions.”

What is known about the variant’s contagiousness and virulence? 

Lorenzo: “Right now, we know this variant has increased rapidly in the U.K. and accounts for a high proportion of new cases there. This suggests a higher transmission rate, but this and other viral properties need to be confirmed in the lab. The first analyses don’t suggest increased virulence only increased transmission.

“So, no reason to get scared or panic. This stresses the importance of molecular surveillance to anticipate the spread of new variants for SARS-CoV2 and other pathogens."

Sala: “Epidemiologic and modeling data suggests it is more transmissible and indeed appears to be outcompeting the other COVID-19 variants. It does not seem to cause more severe illness. However, this is all very preliminary and lacks experimental confirmation.”

Can a variant impact the effectiveness of the vaccine? 

Lorenzo: “These mutations do not seem to impact vaccine efficacy, but they need to be fully characterized. Theoretically, new mutations can impact vaccine efficacy as in other viruses, but the low mutation rate of this virus compared to others like flu or HIV-1 makes this more difficult. 

“However, it is possible that if the vaccine starts to be deployed and is effective, we could observe changes in the virus to adapt and escape from the immune response promoted by the vaccine. But again, the low mutation rate makes the adaptation of this virus to a vaccine less likely.”

How common are variants of viruses and do they generally impact effectiveness of vaccines or treatments?

Lorenzo: “Sometimes variants can have great impacts on vaccines or treatments. That’s why is so important to keep monitoring the variants circulating, to detect any possible mutation that could make vaccination or treatment less effective. However, very low numbers of mutations that could have biological implications for treatments are being observed, so that is good news. This virus seems to be adapting to spread as much as possible and so far, all mutations seem to be increasing transmission, not virulence. That’s probably because there is no evolutionary advantage for this virus to increase virulence.” 

What is a variant?

Lorenzo: “In the case of SARS-CoV2, a variant is being defined as a group of viruses with a mutation or several mutations in common and different from others that are inferred to have a common ancestor. RNA viruses continuously evolve by accumulating mutations.” 

Ison: “Variants occur when there is a change in the genetic material of the virus that results in a change in proteins the virus makes. In this case, there were a few changes related to the spike protein. These have changed the spike, but changes are not predicted to change the efficacy of the vaccine. 

“Studies are ongoing to understand the impact of the variant. While there has been expansion of the virus locally, it is unclear if this is because of enhanced transmissibility. Studies will also determine if the variants are more virulent, meaning they cause more severe disease.”  

How does the discovery of a variant impact our safe behaviors? Does it make our actions/social distancing/masks wearing even more important? 

Lorenzo: “This variant spreads the same way as the previous ones, therefore, the safe behavior measures must remain the same. This variant shows we can’t relax our social precautions. With such high numbers of infected people in the world, spikes in the virus will keep happening. Because the virus keeps changing continuously, the greater number of infected people, the more chances the virus gets to get better at infecting us.” 

Ison: "Variants will occur over time. We should not change our behavior but should focus on not travelling, wearing a mask, maintaining distance and hand hygiene."