The best time for 3rd jab of inactivated vaccine is 7-8 months after the 2nd dose.
Valneva: third dose of VLA2001 administered
7 to 8 months after the second dose of primary vaccination
https://valnevaDOTcom/press-release/valn...e-vla2001/
Sinovac: Longer wait for Sinovac Covid-19 booster improves protection, study finds
https://www.thelancetDOTcom/journals/lan...2/fulltext
The study found that while protection from Covid-19 six months after two doses of the vaccine, also known as CoronaVac, had "declined substantially", a third dose at
eight months resulted in a "remarkable increase" in the concentration of antibodies.
The findings suggest a third dose of CoronaVac® can induce a better neutralization breadth to variants of concern ("VOCs"), including the Delta variant, a rapid immunological memory response, and a long-lasting humoral response.
A third dose of CoronaVac in adults administered
8 months after a second dose effectively recalled specific immune responses to SARS-CoV-2, which had declined substantially 6 months after two doses of CoronaVac, resulting in a remarkable increase in the concentration of antibodies and indicating that a two-dose schedule generates good immune memory, and a primary third dose given
2 months after the second dose induced slightly higher antibody titres than the primary two doses.
Covaxin: Booster dose after
6 months of 2nd Covaxin shot ideal: Bharat Biotech CMD Krishna Ella
https://timesofindiaDOTindiatimes.com/in...635907.cms