BENGALURU: The initial batches of Covid-19 vaccines, likely to be used beginning January 16, will have to be used or discarded within four hours of the vials — each estimated to contain 10 doses — being opened. The reason: non-availability of vaccine vial monitors (VVMs) because the pandemic situation has prompted the government to do away with the open vial policy that allows storage and use of vaccines for a much longer time even after the vial has been opened.
For instance, some vaccines under the Universal Immunisation Programme (UIP) can be used for about four weeks after the vial is ope-ned (for the first time). This cannot be done without VVMs, as they display key indicators, specially the storage temperature, which helps in properly stocking and transporting vials.
“As there will be no VVMs and expiry date on the vial of the vaccine that will be supplied, cold chain maintenance will be of prime importance… Open vial policy will not be applicable and therefore the vaccination officer should mark date and time of opening vial, all open vials need to be discarded after four hours of opening or at the end of session,” the Union health ministry said in its guidelines shared with states. The guidelines added that at every site a supervisor should ensure that the temperature of vaccine carriers are being properly maintained and recorded.
Veteran virologist T Jacob John explained that unlike inactivated vaccines which are allowed to contain agents that keep them sterile, live vaccines like the one SII (Serum Institute of India) is producing, don’t have them. This means that whether or not a vaccine gets contaminated depends on its cold storage.
“Any inactivated vaccine can withstand the break of the cold chain, but live virus vaccines must be maintained at a particular temperature. If that is broken and the temperature goes above 8° Clesius, its potency may go down. Generally, once it is out of the cold chain, such vaccines can be used between 4-6 hours, beyond that if you don’t have a VVM, you aren’t sure if the temperature is being maintained, so it is best not to have an open vial policy,” John said.
This, however, also means that there are high chances of wastage given that the vials have to be used/ discarded within four hours and as per present guidelines only 100 people can be given vaccine shots per site/per day. Incidentally, this has been taken care of given that unlike regular immunisation programmes, which see people drop in as and when on any given day, Covid vaccination is by prior appointment which allows officials to know how many people will be at a site on any day. Unlike the SII vaccine, the one being developed by Bharath Biotech is an inactivated vaccine, and an open vial policy may be applied there. The ministry’s guidelines say that appropriate instructions will be given for different vaccine types.