The COVID-19 vaccines from Pfizer-BioNTec and from Moderna that are now being used are expected to protect more than 90% of people who get both doses.
We do not yet know how long the protection lasts after a two-dose series. With other vaccines, most people do not get the disease at all and those who do, have only mild cases. It is possible that you might need to get a booster dose of this vaccine at some time in the future. More information on the COVID-19 vaccine will be made available as scientists learn more about the long-term protective effects.
And finally, a single dose of one of the current two-dose COVID-19 vaccines will not provide the vaccine’s full protection.