Evaluation of Safety and Potency of Kyasanur Forest Disease (KFD) Vaccine Inactivated with Different Concentrations of Formalin and Comparative Evaluation of In Vitro and In Vivo Methods of Virus Titration in KFD Vaccine

Autor: Ullas Gowda K. Srikanth, Chandranaik B. Marinaik, Amitha Reena Gomes, Doddamane Rathnamma, Sonnahallipura M. Byregowda, Shrikrishna Isloor, Archana Munivenkatarayappa, Mudalagiri D. Venkatesha, Suguna Rao, Apsana Rizwan, Raveendra Hegde
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Biomedicines, Vol 11, Iss 7, p 1871 (2023)
Druh dokumentu: article
ISSN: 2227-9059
DOI: 10.3390/biomedicines11071871
Popis: We evaluated the safety and potency of the Kyasanur Forest disease (KFD) vaccine inactivated with different formalin concentrations in mice, since the side effects due to higher formalin concentrations have been a major reason for vaccine refusal. Furthermore, with an objective to reduce the use of mice in vaccine testing, we performed quantification of the KFD virus by real-time PCR and compared it with in vivo titration in mice. The KFD vaccine prepared in chicken embryo fibroblast cells was inactivated with 0.04%, 0.06%, and 0.08% concentrations of formalin. The vaccine inactivated with 0.04% and 0.06% formalin failed the safety test, whereas the KFD vaccine inactivated with 0.08% formalin was safe and potent with a log protective index of 5678 in mice. This reduced formalin content may induce no/lesser side-effects of pain/swelling which may increase the vaccine acceptance. The real-time PCR on individual KFD vaccine harvests interpreted that when the CT value of each harvest is 50 of the vaccine lies in the tenfold dilution that yields CT values between 31 and 34.
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