Immunogenicity and safety of two-dose or three-dose regimens of inactivated COVID-19 vaccines in patients with pulmonary tuberculosis: a randomized clinical trial

To assess the immunogenicity and safety of two-dose regimen of inactivated COVID-19 vaccines in patients with pulmonary tuberculosis (PTB), and explored the potential benefits of additional dose. 182 PTB patients were randomly (1:1) assigned to the standard-dose group to receive three standard doses of inactivated COVID-19 vaccines, or the double-dose boosting group to receive two standard doses plus a double dose, with a 28-day interval. 40 healthy controls were assigned to receive two doses of inactivated COVID-19 vaccines 28 days apart. The primary endpoint was neutralizing antibodies 28 days after the second vaccination. Two doses of inactivated COVID-19 vaccines induced comparable neutralizing antibodies in PTB patients and the healthy controls, with GMTs against ancestral SARS-CoV-2 of 36.8 vs 31.4 (<i>p</i> = 0.4618) and seroconversion rates of 83.9% vs 87.5% (<i>p</i> = 0.6965). In the PTB patients, a third dose at day 56 led to a modest increase in neutralizing antibodies compared to the second dose, with a GMT fold increase of 1.3-1.8. Most adverse reactions were mild pain at the injection site. Inactivated COVID-19 vaccine was safe and immunogenic in PTB patients, and two-dose immunization could induce moderate level of humoral responses similar to the healthy adults. www.clinicaltrials.gov identifier: NCT05148949.