As the Covid-19 vaccine rollout takes hold in South Africa, we move towards hope. These steps, or vaccinations, towards more safety and freedom however must be carefully regulated in terms of storage and transport conditions. Though both the J&J and Pfizer vaccines are effective against the virus, they are formulated differently. We discussed the science behind some of the different Covid-19 vaccines here, and now will focus on the two South African candidates.
The Pfizer vaccine uses Messenger RNA, or mRNA to convert patient cells to produce a specific coronavirus protein. This teaches the body how to respond if exposed to coronavirus. Although only one virus protein is present in the patient, the body reacts as if fighting a genuine infection and therefore learns the appropriate immune response.
This modern science is inspirational, as compared to traditional formulations it allows much larger volumes of the vaccine to be produced faster. mRNA is, however, very fragile and therefore needs a very low storage and transport temperature. For the Pfizer mRNA covid-19 vaccination this means a storage temperature of -70C. The Ebola vaccine required similar conditions, and it requires dry ice for transport and specialised freezers for storage.
The Pfizer vaccine arrives in thermal shippers, which can be used as temporary storage units for up to 30 days, if refilled with dry ice every 5 days. When patients are ready, doses can be stored for five days at refrigerated 2-8C conditions. Accurate measurement of temperature is absolutely vital from the vaccines being shipped to administered. The efficacy of this vaccine relies on easily damaged enzymes, so evidence that appropriately low temperatures have been maintained is vital.
To assist with this, both the Tempod 90S and Tempod 100x can offer confidence. They monitor temperature down to -90 and -100 C respectively. The Tempod 90S is a single use temperature data logger, perfect for monitoring covid-19 vaccines during distribution under dry ice conditions. It is probe-less and therefore can be placed inside the shipper, with the vaccines. It has a built-in USB port for simple configuration and easy download of temperature recordings. The Tempod 100x, on the other hand, is re-usable, with an external sensor probe so the device sits outside the freezer, with the probe on a 1m cable, monitoring the temperature, on the inside of the freezer.
This covid-19 vaccine is also based on the genetic instructions for building the spike protein of this coronavirus. It uses double stranded DNA rather than the single-stranded RNA of the Pfizer vaccination. J&J have built this vaccine on years of research into adenovirus-based vaccines. The first of this kind was a vaccination against Ebola, and they are currently applying this research to H.I.V and Zika.
This adenovirus-based vaccine is more durable than the mRNA model. DNA is not as fragile, so the vaccine is more stable, and therefore storage conditions need not be so severe. The J&J covid-19 vaccine must be stored between 2C and 8C, which can be achieved with standard refrigeration. The transport and storage of this vaccine is therefore far less arduous, and it is more suitable for widespread distribution.
Once the multidose vial seal is broken, all remaining doses can be stored for 6 hours in the same refrigeration condition or even at room temperature for 2 hours. This makes it a great candidate for use in clinics and rural communities without specialised equipment.
Timestrip products can offer reassurance that appropriate conditions of the J&J covid-19 vaccine have been maintained through distribution and storage. The Timestrip VRM 30 vaccine refrigeration monitor measures conditions for up to 30 days at 2-8C. It also indicates when 10, 20 and 30 days have passed to indicate progress towards vaccine expiration date.
The Timestrip VOR12 is ideal for use during transit as it tracks and records any temperatures in excess of 8C. It monitors this accumulated temperature breach over 12 hours.
We are proud to assist with the vaccine rollout programme, as it represents not only movement towards freedom from covid-19, but also scientific progress in general. It is our great hope that by sourcing and stocking the right devices, we can facilitate successful vaccination against this and many other diseases in the future.
We’re very grateful to all involved in the heroic effort of tackling this virus. Please do get in touch and we’ll be happy to provide the appropriate solutions for your temperature monitoring needs.