After waiting for months, people in several countries have finally started getting vaccinated for coronavirus. In Delhi, for instance, Chief Minister Arvind Kejriwal recently announced that around 51 lakh people will be administered the vaccine shots.
Vaccines take years of research and trials to be made. In a series of explainers, the World Health Organisation (WHO) elaborated on how vaccines are developed, stored and thereafter shipped.
What is a vaccine made of?
Simply, vaccines contain “tiny fragments of the disease-causing organism or the blueprints for making the tiny fragments,” mentioned WHO in its article. Along with this, it also contains other ingredients — each of which are tested for safety in the manufacturing process — to keep the vaccines safe and effective. These include antigen, preservatives, stabilisers, surfactants, residuals, diluent, and adjuvants. These ingredients are mostly those that have been used in many other vaccines for decades in billions of doses.
How are vaccines developed?
Every vaccine undergoes “extensive and rigorous” testing and screenings and evaluations to determine the antigen that should be used to invoke an immune response. This does not involve testing on humans but on animals. If the vaccine triggers an immune response, it is then tested in human clinical trials in three phases, explains WHO.
In the first phase, a select number of volunteers are administered the vaccine to test if it generates an immune response and to determine the right dosage. In the second phase, it is then given to several hundred volunteers. This phase involves multiple trials to evaluate the effect of different formulations of the vaccine on various age groups. Included in this is another group that is not given the vaccine to compare the results and understand if the changes in the vaccinated group have happened by chance or because of the vaccine.
Finally, in the third phase, the vaccine is given to an even larger group of volunteers and compared to a similar group of people who are not vaccinated. This phase is usually conducted across multiple countries and sites within a country.
Once the results of these clinical trials are obtained, officials in each country closely review the data and then decide if the vaccine can be authorised for use. “A vaccine must be proven to be safe and effective across a broad population before it will be approved and introduced into a national immunization programme. The bar for vaccine safety and efficacy is extremely high, recognizing that vaccines are given to people who are otherwise healthy and specifically free from the illness,” reads the WHO article. Further monitoring continues to take place once the vaccine is introduced.
How is it packaged?
WHO explains that once the vaccine has been made in bulk quantities, it is stored in glass vials and then carefully packaged for safe cold storage and transport. The packaging is done in a way to ensure it is able to withstand extreme temperature and also other risks involved in being transported globally. Most of the vaccines are stored between 2-8 degrees Celsius. The vaccine can become less effective or unsafe if it is too hot or cold. But some of the new vaccines are also stored at -70 degrees Celsius.
How are vaccines shipped?
“Specialised equipment” is used to keep the vaccine safe. Once it reaches the destination country, refrigerated lorries transport the vaccine from the airport to the warehouse cold room. It is then transported to regional centres in portable iceboxes. New technologies have invented some portable devices that can keep vaccines at the cold temperature for several days without needing electricity,” WHO adds.
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