Delivering COVID-19 vaccine

From all indications, it appears there are at least three COVID-19 vaccine candidates that should be ready for a first phase vaccination programme by next March. While we do not know exactly which vaccine we will be getting – or purchasing – it is even possible that we may be using a combination of vaccines. But whatever the answer to those questions, our health sector and other related agencies will have to prepare for the most massive vaccination programme this country has ever seen.
Preparations will have to be made in several areas: firstly, to sensitise the public on the nature of the immunisation plan, the possible side effects of the vaccine, and how to deal with those. Secondly, to initiate the inoculation process with all health-care workers. The second-tier demographic would be the elderly, most likely above sixty-five, especially those with co-morbid conditions that place them at higher risk of becoming infected. Those co-morbid conditions must be determined and declared. The Government must at once begin to identify and locate those who are in those high-risk categories, and coordinate the information with our health-care system so that an orderly and efficient immunisation programme can be planned.
Vaccination points would have to be identified – whether at all hospitals or health centres in the country. Vaccinators would also have to be identified, most likely from the nursing profession, since those professionals are already trained for the job. However, the most challenging aspect of the COVID-19 immunisation programme would be to ensure the necessary cold chain is in place. Vaccines are sensitive biological substances, and “cold chain” includes all of the materials, equipment and procedures used to maintain vaccines in the required temperature range of +2 °C to +8 °C from the time of manufacture until the vaccines are administered to individuals.
We would have to ensure there is a minimum of “cold chain incidents” which occur when vaccines are exposed to a temperature outside the required temperature range for any period of time and the potency of the vaccine is potentially compromised. Failure to adhere to cold chain requirements may therefore reduce vaccine potency, resulting in lack of protection against the COVID- 19 virus.
It is almost certain that our present cold chain would be inadequate for the demands of the massive immunisation programme. While purpose-built refrigerators are the preferred refrigerators for vaccine storage by health care providers and are required for vaccine storage at public health units, it is unlikely that we would be in a position to supply these to all the health centres. The main features of a purpose-built refrigerator include: Recorder; Microprocessor electronic control and alarm; Forced air evaporator coils Interior lighting; Easy access to vaccines and View through glass doors.
In a purpose-built refrigerator, nearly all of the internal space can be used for storing vaccines. The temperature regulation mechanism ensures narrow tolerances with internal temperatures. This provides appropriate temperature regulation;
– Ongoing air circulation ensures that the temperature is distributed evenly;
– An internal temperature between +2 °C and +8 °C is maintained;
– An evaporator operates at +2 °C, preventing the vaccine from freezing;
– The temperature recovery system is very quick; and
– The forced air circulation helps to keep internal temperatures between +2 °C and +8 °C even when the ambient temperature changes.
Although it is not recommended, since they do not have the above-mentioned features, it is possible (although very complex) to manage kitchen and bar refrigerators to reduce the risk of heating and/or freezing the vaccines, which would destroy their efficacy. The necessary modifications and measures should be explained to health workers, and they have to be cautioned that there can be no deviation from the specified protocols.
It is envisaged that there would have to be vaccine stores in each Region from where they can be distributed to vaccination centres in ice-lined refrigerators or insulated containers.