CNN reports a significant proportion of adults all over the world say they have major concerns about receiving a vaccination for the novel coronavirus.
Neil Johnson is a physicist at George Washington University who is studying vaccine skepticism on social media.
Johnson says among people who aren't anti-vaxxers, but are dubious about a COVID-19 vaccine, have four commonly held objections.
The first is whether the vaccine is safe; the second is whether the vaccine is actually necessary.
The third concern surrounds trust in the establishment and the pharmaceutical companies producing the vaccines.
The fourth major concern is the perceived uncertainty in the science of immunology.