In vitro determination of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies induced in serum samples from recipients of the CoronaVac vaccine showed a short protection period against the original virus strain and limited protection against variants of concern. These data provide support for vaccine boosters, especially variants of concern circulate.
Keywords: COVID 19; SARS-CoV-2; Thailand; coronavirus disease; inactivated SARS-CoV-2 vaccine; neutralizing antibodies; respiratory infections; severe acute respiratory syndrome coronavirus 2; vaccination; viruses.