It is over a year now, since the Covid-19 pandemic surged in 2020, the world turned its focus to the hope of a vaccine. Now, several successful vaccines have been developed, approved for use and rolled out, both thanks to the combined efforts of the biomedical community, and the essential role of animals, in helping us achieve our goal of developing a safe and efficacious vaccine at more than one stage of the process has become even more vital.
Several questions have been raised and continues to be raised, as the pandemic has brought the attention around science, and it is becoming increasingly scrutinized how Covid-19 vaccines managed to be developed so quickly, when other vaccines take decades, and ask if some stages of testing were skipped, the answer is that the unprecedented global effort and vast investment to find a cure has simply sped up the normal process. Innovative methods have been used, but the vaccines have gone through every regulatory stage, including those safety stages that require the use of animals.
Several successful Covid-19 vaccine candidates that were developed and are in the process of being approved across countries and beyond relied on animal studies during the early stages of basic research, all the way through to preclinical testing where animals are used to prove a vaccine’s safety.
Animal testing is critical to ensure that the vaccine does not end up making the infection worse, or even fatal.
Animal testing is critical to ensure that the vaccine does not end up making the infection worse, or even fatal. A relevant species is used to test these trial vaccines depending on the disease in question, but most commonly the preclinical testing will involve mice, rats or monkeys. Following this, the vaccine moves on to its first human trials – known as Phase I of a clinical trial – where a small number of healthy, human volunteers are vaccinated to see if the vaccine acts in the same way in humans. In an article that explains What is a vaccine? and how it works is explained in a video.
The recently approved US/German Pfizer/BioNTech vaccine underwent preclinical testing using mice, testing different doses of vaccine on groups of eight mice per dose. Testing in mice was initially to see if the vaccine would produce any kind of immune response, and these mice were then monitored closely for up to 14 days to see if this was the case.
However, infected mice are not usually affected by the coronavirus, and so further testing in monkeys is necessary to see if the vaccine can actually protect the individual from the potentially devastating effects of an infection. In this case, 12 rhesus macaques were used to test the vaccine, and after exposure to the virus all of the monkeys which had received the vaccine were protected from infection. The Moderna vaccine was examined in much the same way, this time using mice and 24 rhesus macaques.
The Indian vaccine COVAXIN Newborn Calf Serum is used for the preparation/ growth of vero cells. Different kinds of bovine and other animal serum are standard enrichment ingredient used globally for vero cell growth. Vero cells are used to establish cell lives which help in production of vaccines. This technique has been used for decades in Polio, Rabies, and Influenza vaccines.
These vero cells, after the growth, are washed with water, with chemicals (also technically known as buffer), many times to make it free from the newborn calf serum. Thereafter, these vero cells are infected with corona virus for viral growth. The vero cells are completely destroyed in the process of viral growth. Thereafter this grown virus is also killed (inactivated) and purified. This killed virus is then used to make the final vaccine, and in the final vaccine formulation no calf serum is used, according to the India’s Ministry of Health statement.
Going forward, the research process will likely have changed the way future vaccines are developed, but it is important to note that the accomplishments the world of science has delivered to the world today is thanks in part to a small, but significant amount of animal research.