Thermostable respiratory synctial virus (RSV) vaccine compositions
View Patent ↗Methods for improving the drying yield and stability of RSV vaccines comprising a highly thermolabile enveloped live virus and/or one or more RSV protein subunits, are described. Methods for rapid drying of RSV formulations containing between 17.5% and 60% w/w of a non-polymeric sugar and using either conduction or radiation dominant drying mechanisms, are disclosed. The disclosed methods provide for; 1) a dried RSV formulation with improved stability profile; 2) faster drying; and 3) integration of dried RSV into a primary device (such as dual chamber cartridges, foil-pouch devices etc.), pre- as well as post-drying.
1. A method for drying a vaccine composition comprising a live attenuated respiratory syncytial virus (RSV) comprising the steps of:
a) providing an aqueous composition in a primary container comprising the live attenuated RSV, a buffer, and from 17.5% w/w to 60% w/w of one or more non-polymeric sugars, wherein the pH of the buffer is between 6 and 8;
b) freezing the aqueous composition by aliquoting the aqueous composition on a chilled mold or surface having a temperature less than −100° C., thereby forming at least one frozen pellet comprising the buffer in frozen form; and
c) drying the aqueous composition by microwave vacuum drying.
2. The method according to claim 1 , characterized in that the sugar is selected from monomeric and/or dimeric sugar molecules.
3. The method according to claim 2 , wherein the sugar is glucose, galactose, maltose, sucrose, trehalose, fructose, lactose, saccharose, mannitol, sorbitol, xylitol or a combination thereof.
4. The method according to claim 3 , wherein the sugar is sucrose, trehalose or a combination thereof.
5. The method according to claim 1 , wherein the amount of the sugar in the aqueous composition is chosen from the group that consists of the ranges 20-55% w/w, 20-50% w/w, 20-45% w/w, 25-45% w/w, 25-47.5% w/w, 25-40% w/w, 30-47.5% w/w, 30-40% w/w, 25-35% w/w or 27-30% w/w.
6. The method according to claim 1 , wherein the buffer is selected from Tris, histidine, phosphate and combinations thereof.
7. The method according to claim 1 , wherein the microwave vacuum drying comprises applying microwave radiation in a traveling wave format at a power in a range of between 0.5 and 8 KW/hr/Kg to the frozen pellet under a pressure below atmospheric pressure.
8. The method according to claim 7 , wherein the pressure is a pressure in the range of 20 to 500 mTorr.
9. The method according to claim 8 , wherein the pressure is a pressure in the range of 20 to 200 mTorr.