However, the use of volatile diethyl-ether (ether) has several drawbacks, such as risk of explosion, local toxicity (irritation of skin and eyes) as well as toxicity after repeated or prolonged exposure resulting in organ damage. Initial splitting technology, introduced in the 1960s, was based on diethyl-ether extraction of the virus. Influenza subunit vaccines contain additional purification steps to remove the nucleocapsids and lipids before formulation.Īt the expense of immunogenicity split influenza vaccines, and also subunit influenza vaccines, are more common nowadays than WIV vaccines, because subunit vaccines are less associated with side effects. In the case of split vaccine the virus is split and the splitting agent removed prior to formulation and sterile filtration. ![]() Subsequently, the intermediate bulk is inactivated and formulated before sterile filtration and fill & finish. The classical WIV production starts with influenza virus growth in eggs followed by a clarification step and zonal ultracentrifugation. Each of these vaccines has its specific advantages and disadvantages as reported elsewhere: Beside vaccines made from the influenza virus produced in eggs or mammalian cells, a subunit vaccine based on recombinant haemagglutinin (HA) produced in insect cells is licensed. Inactivated influenza virus vaccines include whole inactivated virus vaccines (WIV), split virus vaccines, subunit vaccines (split virus from which the nucleocapsid is removed) and virosomal influenza vaccines (reconstituted virus envelope material). The current influenza vaccines on the market are live attenuated influenza vaccines and inactivated influenza virus vaccines. Although in potential, the worldwide vaccine production capacity of 850 million doses per year is nearly matching the seasonal demand for influenza vaccine, this amount is not sufficient to cover demands for a pandemic outbreak. Yearly, genetic shift and drift of influenza virus necessitate the manufacturing of high numbers of influenza vaccine with yearly adapted vaccine strains. Especially ether split formaldehyde product showed low recovery and least stability over a period of five months. The beta-propiolactone inactivation on average resulted in higher recoveries compared to processes using formaldehyde inactivation. In all processes, major product losses were measured after sterile filtration with larger losses for split virus than for WIV. All products were sterile filtered and subjected to a 5 months real time stability study. Removal of ether was established by centrifugation and evaporation, whereas removal of Triton-X100 was performed by hydrophobic interaction chromatography. For splitting of the viral products in presence of Tween ®, either Triton ™ X-100 or di-ethyl-ether was used. The inactivation of the virus was performed with either formaldehyde in phosphate buffer or with beta-propiolactone in citrate buffer. The main unit operation for purification was sucrose gradient zonal ultracentrifugation. ![]() One clarified harvest of influenza H3N2 A/Uruguay virus prepared on 25.000 fertilized eggs was divided equally over six downstream processes. Four split and two whole inactivated virus (WIV) influenza vaccine bulks were produced and compared with respect to release criteria, stability of the bulk and haemagglutinin recovery. The aim of this study was to evaluate the impact of different inactivation and splitting procedures on influenza vaccine product composition, stability and recovery to support transfer of process technology. ![]() Lanes numbered above right gel: 1.1 allantoic fluid, 1.2 clarified allantoic fluid, 3.0 purified virus, 3.1B beta-propiolactone (BPL) inactivated virus, 5.1B sterile filtered bulk product of BPL inactivated virus, 5.1BT sterile filtered bulk product of BPL inactivated Triton split virus, 5.1BE sterile filtered bulk product of BPL inactivated ether split virus, M marker proteins.įractions 3.0 (whole virus), 3.1F (formaldehyde inactivated whole virus) and 3.1B (BPL inactivated whole virus) evaluated by SDS-PAGE resemble the WIV product fractions 5.1F and 5.1B no major change in protein composition due to inactivation or sterile filtration is visible. ![]() Lanes numbered above left gel: 1.1 allantoic fluid, 1.2 clarified allantoic fluid, 3.0 purified virus, 3.1F formaldehyde inactivated virus, 5.1F sterile filtered bulk product of formaldehyde inactivated virus, 5.1FE sterile filtered bulk product of formaldehyde inactivated ether split virus, 5.1FT sterile filtered bulk product of formaldehyde inactivated Triton split virus, M marker proteins. S1 Fig: Coomassie Brilliant Blue stained SDS-PAGE gels with different fractions ( Fig 1) of the influenza vaccine downstream processes and marker proteins.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |