Question

What are the similarities and differences of the different COVID-19 variants and what are its implications to humans?
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Answer 1

Answer:

Viruses constantly change through mutation. When a virus has one or more new mutations it’s called a variant of the original virus. Currently, the Centers for Disease Control and Prevention has identified two variants of the virus (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) as variants of concern.

Delta (B.1.617.2). This variant is nearly twice as contagious as earlier variants and might cause more severe illness. The greatest risk of transmission is among unvaccinated people. People who are fully vaccinated can get vaccine breakthrough infections and spread the virus to others. However, it appears that vaccinated people spread COVID-19 for a shorter period than do unvaccinated people. While research suggests that COVID-19 vaccines are slightly less effective against the delta variant, the Pfizer-BioNTech, Moderna and Janssen/Johnson & Johnson COVID-19 vaccines still appear to provide protection against severe COVID-19.

Omicron (B.1.1.529). This variant might spread more easily than other variants, including delta. But it’s not yet clear if omicron causes more severe disease. It’s expected that people who are fully vaccinated likely can get breakthrough infections and spread the virus to others. However, the COVID-19 vaccines are expected to be effective at preventing severe illness. This variant also might reduce the effectiveness of some monoclonal antibody treatments.

The alpha, gamma and beta variants continue to be monitored but are spreading at much lower levels in the U.S. The mu variant is also being monitored.

Additional dose. The CDC recommends a third dose of an mRNA COVID-19 vaccine for some people with weakened immune systems, such as those who have had an organ transplant. People with weakened immune systems might not develop enough immunity after vaccination with two doses of an mRNA COVID-19 vaccine. An additional dose might improve their protection against COVID-19.