RESUMO
One of the most preferable characteristics for a COVID-19 vaccine candidate is the ability to reduce transmission and infection of SARS-CoV-2, in addition to disease prevention. Unlike intramuscular vaccines, intranasal COVID-19 vaccines may offer this by generating mucosal immunity. In this open-label, randomised, multicentre, phase 3 clinical trial (CTRI/2022/02/40065; ClinicalTrials.gov: NCT05522335), healthy adults were randomised to receive two doses, 28 days apart, of either intranasal adenoviral vectored SARS-CoV-2 vaccine (BBV154) or licensed intramuscular vaccine, Covaxin®. Between April 16 and June 4, 2022, we enrolled 3160 subjects of whom, 2971 received 2 doses of BBV154 and 161 received Covaxin. On Day 42, 14 days after the second dose, BBV154 induced significant serum neutralization antibody titers against the ancestral (Wuhan) virus, which met the pre-defined superiority criterion for BBV154 over Covaxin®. Further, both vaccines showed cross protection against Omicron BA.5 variant. Salivary IgA titers were found to be higher in BBV154. In addition, extensive evaluation of T cell immunity revealed comparable responses in both cohorts due to prior infection. However, BBV154 showed significantly more ancestral specific IgA-secreting plasmablasts, post vaccination, whereas Covaxin recipients showed significant Omicron specific IgA-secreting plasmablasts only at day 42. Both vaccines were well tolerated. Overall reported solicited reactions were 6.9% and 25.5% and unsolicited reactions were 1.2% and 3.1% in BBV154 and Covaxin® participants respectively.
RESUMO
The WHO pre-qualified rotavirus vaccine, ROTAVAC®, is derived naturally from the neonatal 116E rotavirus strain, and stored at -20°C. As refrigerator storage is preferable, immunogenicity and safety of liquid formulations kept at 2-8°C, having excipients to stabilize the rotavirus, with or without buffers, were compared with ROTAVAC® in different clinical studies. Study-1, the pivotal trial for this entire product development work, was a randomized, single-blind trial with two operationally seamless phases: (i) an exploratory phase involving 675 infants in which two formulations, ROTAVAC 5C (LnHRV-1.5 mL and LnHRV-2.0 mL) containing buffer and excipients to stabilize the virus against gastric acidity and temperature, were compared with ROTAVAC®. As the immune response of ROTAVAC 5C (LnHRV-2.0 mL) was non-inferior to ROTAVAC®, it was selected for (ii) confirmatory phase, involving 1,302 infants randomized 1:1:1:1 to receive three lots of LnHRV-2.0 mL, or ROTAVAC®. Primary objectives were the evaluation of non-inferiority and lot-to-lot consistency. The secondary objectives were to assess the safety and interference with the concomitant pentavalent vaccine. As it was separately established that buffers are not required for ROTAVAC®, in Study-2, the safety and immunogenicity of ROTAVAC 5D® (with excipients) were compared with ROTAVAC® and lot-to-lot consistency was assessed in another study. All lots elicited consistent immune responses, did not interfere with UIP vaccines, and had reactogenicity similar to ROTAVAC®. ROTAVAC 5C and ROTAVAC 5D® were immunogenic and well tolerated as ROTAVAC®. ROTAVAC 5D® had comparable immunogenicity and safety profiles with ROTAVAC® and can be stored at 2-8°C, leading to WHO pre-qualification.Clinical Trials Registration: Clinical Trials Registry of India (CTRI): CTRI/2015/02/005577CTRI/2016/11/007481 and CTRI/2019/03/017934.