While much attention has been given to how quickly the Covid-19 vaccines were developed, scientists have been studying pandemic coronaviruses and vaccines to protect against them for over a decade.
“Sometimes people think these vaccines just popped out of nowhere over a period of 4 months,” Dr Peter Hotez, dean of Baylor College of Medicine’s National School of Tropical Medicine, told MSNBC in December.
“This is not a four-month process. This is a 17-year process. The discovery and development of vaccines for coronavirus began 17 years ago after SARS emerged in 2003. That was the first big pandemic coronavirus,” Hotez explained.
This is when scientists identified the coronavirus spike protein as a possible target for a vaccine, said Hotez. All coronaviruses share a similar spike protein, which the virus uses to infect cells.
So when Chinese researchers publicly posted the genetic sequence in January 2020 for the novel coronavirus or SARS-CoV-2 that causes Covid-19, vaccine scientists were able to build on existing knowledge and vaccine technology.
Some of the “new” vaccine technologies being used for Covid-19 vaccines is not new at all and has been in laboratory testing and clinical trials for years.
The AstraZeneca-Oxford, Johnson & Johnson, and other Covid-19 vaccines are based on an adenovirus vector vaccine platform. These use a modified cold virus to deliver coronavirus genes to the body, which trains the immune system to recognise and attack the coronavirus.
Vaccine developers started developing adenovirus vector vaccines in the early 2000s for diseases such as AIDS, malaria, and tuberculosis, with several clinical trials since then using this platform.
Another newer technology is the messenger RNA (mRNA) platform used by Pfizer-BioNTech and Moderna-NIAID for their jabs.
These deliver the genetic instructions — in the form of mRNA — for the coronavirus spike protein to the cells, where it stimulates an immune response.
Research on mRNA vaccines began in the early 1990s. Since then, laboratory and clinical trials have been carried out using this platform to protect against diseases such as Ebola, Zika, and influenza.
Scientists were able to work quickly to develop candidate Covid-19 vaccines. But clinical trials — which measured the vaccines’ safety and efficacy — ran at their usual pace.
These “were as large and as careful as any that have been done for other vaccines,” said Sostman.
One factor that sped the development of Covid-19 vaccines was the massive amount of government and other funding. This allowed scientists and vaccine makers to focus on these vaccines, and encouraged companies to start producing doses early.
The “main time saver,” said Sostman, was having the drug companies gear up for production before the FDA had approved the vaccines. “That was the result of government guarantees to purchase authorised vaccines,” he said.
Source: Healthline