The COVID-19 vaccine is the brightest light of hope but with it comes uncertainty. Scientists aren't positive how long the antibodies from the current vaccines will protect against the virus. It's possible people will need an annual shot. There's also uncertainty in how SARS-CoV-2 will mutate. "There are millions of people currently infected so this gives the virus incredible opportunity to create new variants, which it's constantly doing all the time," said Dallas County Medical Society's Dr. John Carlo. Scientists believe the new mRNA technology used to create two of the three COVID-19 vaccines will allow them to easily tweak the vaccines to fight of emerging variants.