COVID-19 variants: What first responders need to know
Learn about the differences between each strain, how transmissible they are, and what they mean for local communities
This article, originally published on Jan. 21, 2021, has been updated with new information.
In the time since the original strain of COVID-19 was identified in December 2019, several notable variants of the virus have been discovered around the world.
Learn what health experts are saying about the new variants, plus whether the FDA-approved COVID-19 vaccines are effective in protecting vaccinated individuals from the new strains.
Variant classification and notable strains
Multiple variations of the original COVID-19 virus have been detected around the world, and several have been found in the United States. In response, the Department of Health and Human Services established the SARS-CoV-2 Interagency Group (SIG), which assisted the CDC in defining three classes of COVID-19 virus variants:
1. Variants of Interest (VOI): According to the CDC, this is "a variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity."
There are currently four VOIs circulating in the U.S.:
2. Variants of Concern (VOC): These are "a variant for which there is evidence of an increase in transmissibility, more severe disease (increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures," per the CDC.
There are currently five VOCs emerging in the U.S.:
3. Variants of high consequence (VOHC): According to the CDC, "a variant of high consequence has clear evidence that prevention measures or medical countermeasures (MCMs) have significantly reduced effectiveness relative to previously circulating variants."
There are no variants that rise to this level currently in the world.
How do the new variants differ from the original strain?
Each COVID-19 variant has one or more mutations that differentiate them from the original strain discovered in 2019. The four VOIs circulating in the U.S. share one specific mutation – D614G – and are associated with faster transmission of the virus.
The five VOCs in the U.S. also share the D614G mutation and spread more easily than the original strain. However, they are also linked to more severe cases of the disease.
Where have the new variants been found in the U.S.?
Of the five VOCs circulating in the country, the B.1.1.7 variant has been reported in all 50 states for a total of 20,915 cases as of April 12, according to the CDC.
The B.1.351 variant has been found in more than half of the states in the U.S., with a total of 323 reported cases. There are 15 states without a case of this specific variant, as of April 12, 2021.
The P.1 variant has been found in a patchwork of states, with a total of 497 reported cases.
Are the COVID-19 variants more dangerous?
The three VOIs, while more easily transmissible, do not appear to be more deadly, according to CDC research. The five VOCs, particularly B.1.1.7, P.1 and B.1.351, however, do appear to make individuals more sick.
Are the COVID-19 variants more contagious?
Yes, according to the CDC, it appears that the three VOIs and the five VOCs are more easily transmissible and therefore more contagious than the original COVID-19 strand.
Can an individual who has already had COVID-19 be reinfected by variant strains?
Yes, individuals who became sick from the original COVID-19 strand can be reinfected by a COVID-19 variant, per the CDC.
Will the approved COVID-19 vaccines still work against the new variants?
Researchers are working to determine the efficacy of approved vaccines against the new variants as they emerge. Currently, there is no evidence to suggest that they will not work to prevent severe sickness; however, it's possible that the immune response triggered by the COVID-19 vaccine may not be as effective against some of the new strains.
In addition, the CDC reported that "specific monoclonal antibody treatments may be less effective for treating cases of COVID-19" if the variant has the L452R or E484K substitution in the spike protein.
L452R is present in:
E484K is present in:
- Only some strains of B.1.526 and B.1.1.7
Robert Bollinger, M.D., M.P.H., an expert on the SARS-CoV-2 virus at Johns Hopkins University, said researchers are tracking the characteristics of each new strain, and are poised to make changes to the vaccine should a major mutation occur.
“We deal with mutations every year for flu virus, and will keep an eye on this coronavirus and track it,” Bollinger said. “If there would ever be a major mutation, the vaccine development process can accommodate changes, if necessary,”