Updated: December 2, 2020 7:49:59 pm
The BNT162 vaccine from Pfizer and its partner BioNTech claims to offer up to 95% protection against Covid-19 (AP)
When Pfizer’s first Covid-19 vaccine takes place next week in the UK, it would mark the faster vaccine development for a pandemic in history by following all mandatory stages (Russian and Chinese vaccines were approved before Phase III trials). From the dosing of the first trial participants on May 5 through approval for emergency use authorization In the UK in six months, the breakneck pace of development of the BNT162 vaccine by Pfizer and its partner BioNTech, which claims to offer up to 95% protection against Covid-19, sums up the severity of the pandemic that has killed more than 1.46 million people and 62.8 million infected.
In addition to Pfizer, Moderna Inc, which was one of the first companies to start human clinical trials of its mRNA vaccine on March 16, you have already applied for the emergency use license In the US, the Serum Institute of India, which is testing a version of the AstraZeneca-Oxford vaccine, is also expected to do the same in the next two weeks. The University of Oxford had begun phase I trials of its ChAdOx1 nCoV-19 vaccine on April 23.
The developments mark a notable change, as there was no antidote for the virus and the most optimistic prediction was a vaccine in mid-2021.
According to the World Health Organization (WHO), the average time to develop and make a vaccine available to the public so far has been 16 years. In fact, the vaccine that is remotely close to the rate of Covid-19 is the mumps vaccine, which took about 4 years to obtain all the necessary permits and licenses. So far, only smallpox has been officially declared eradicated by vaccination.
How did Covid-19 vaccines develop so quickly?
What helped scientists develop a Covid-19 vaccine in record time is the fact that it didn’t need to be made from scratch. Scientists had started making vaccines for SARS and MERS, which belong to the coronavirus family, during their outbreaks in 2003 and 2012, respectively, only to abandon efforts when the outbreaks died out.
In addition, Pfizer and Moderna have used the new mRNA technology for their vaccines, which are faster to develop as they do not require companies to produce weakened proteins or pathogens for the vaccine. MRNA from genetic material is easy to make in a lab, and making an mRNA vaccine instead of a protein can save months of time.
Quixplained: How a vaccine travels from the factory to the syringe
Additionally, it should be noted that for most Covid-19 vaccines on the cusp of their release or those that have already received approval, the mandatory clinical trial process, designed to test whether injections are safe and effective, was compressed into months in what normally takes about ten years. For example:
Phase i: In this step, the experimental vaccine is administered to humans, usually between 20 and 80 subjects, to test its safety and dose, in addition to evaluating whether it stimulates the immune system. While this process generally takes one to two years, for Covid-19 testing, it took about three months to complete. 📣 Express Explained is now on Telegram
Phase ii: At this stage, about several hundred individuals, divided into age groups such as children and the elderly, are dosed in a randomized, double-blind, placebo-controlled study. This process usually takes around three years, but for Covid-19 vaccines, it took 2-3 months to complete.
Phase III: This is the most crucial stage, where the candidate vaccine is given to thousands of people, and can typically take two to four years. However, most drug manufacturers combined this with Phase II to speed up the process.
Regulatory review: After Phase III trials, the vaccine developer submits a license application to the regulatory authority of their respective country, and final approval can take months or years. However, in emergency situations, such as the Covid-19 pandemic, authorities grant the Emergency Use Authorization (USA) within weeks.
At Pfizer’s manufacturing plant in Kalamazoo, Michigan, you see freezers that can be used to store the coronavirus disease (COVID-19) vaccine (Reuters)
How long did it take to develop other notable vaccines in the past?
Smallpox: So far, only smallpox has been officially declared eradicated by vaccination. According to the WHO, it was in 1798 that Edward Jenner in the UK created the first successful smallpox vaccine. However, it was not until 1959 that guidelines for the production and quality control of smallpox vaccines were first adopted. The disease, which had a mortality rate of between 30% and 40%, was finally eradicated in 1980.
Influenza: Like Covid-19, influenza is a respiratory illness caused by influenza viruses. One of the most devastating was the “Spanish” influenza pandemic in 1918-1919, which caused approximately 21 million deaths worldwide. Only in the mid-1930s were the first clinical trials of influenza vaccines conducted. Almost eight years later, the efficacy and safety of inactivated vaccines were studied between 1942 and 1944. In 1945, the vaccine was licensed in the United States.
Measles, Mumps, and Rubella (MMR): Measles killed nearly 12,000 people in the US in 1916, and 75 percent of them were 5 years old or younger. However, it was not until 1954 that American physician Thomas Peebles first isolated the measles virus after an outbreak at a school near Boston. Four years later, the vaccine was tested in children and finally licensed in 1963. Mumps received its own vaccine in 1967 and rubella in 1969. It was Maurice Hilleman of the Merck Institute who developed a combination vaccine in 1971.
The polio vaccine was declared safe and effective for use by the US government in late 1955. (Representative)
Polio: The first major polio epidemic occurred in Vermont, United States, in 1894 and in 1916, more than 27,000 people were paralyzed by the disease and at least 6,000 died from it. Work to develop a polio vaccine began in the 1930s, but it was only in 1953 that Dr. Jonas Salk announced an effective polio vaccine. Salk initially tested his inactivated polio vaccine on a small number of former polio patients, his wife, and three children. In 1954, more than 1 million participants were enrolled for large-scale clinical trials. It was the first trial of a vaccine to implement a double-blind, placebo-controlled design, according to Lifescience. The vaccine was declared safe and effective for use by the US government in late 1955.
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