The only way that scientists are going to end this current pandemic is to develop vaccines and immunize enough people to reach immunity in about 75 percent of the population from the vaccines or by having been infected with the disease (Science, June 23, 2020). To make previous vaccines, scientists took the offending virus and weakened or killed it so it would be less likely to harm humans. It used to take five or more years to make the vaccines and test them for benefit and safety on cell cultures, on animals and finally on humans.
A Magnificent Breakthrough
In January 2020, Chinese researchers worked out the map of the genetic sequence of the coronavirus and published their results (Nature, Jan 2020;579(7798):265-269). This brilliant and tedious work opened the door for a fast way to make effective vaccines to help stop the current pandemic. Now, less than five months after this incredible breakthrough, researchers have developed vaccines that are being tested to see if they can stop the pandemic. So far, the new type of vaccine has been shown to produce a strong antibody response and virus protection in Rhesus monkeys (Nature, July 30, 2020). Vaccines are being tested by:
• NIAID (National Institute of Allergy and Infectious Diseases) and Moderna
• Oxford University and Astra Zenica
• Harvard Medical School and Johnson & Johnson
• CanSino, a collaboration between China and Canada
• and several others
The New Vaccines Do Not Contain the Whole Virus
SARS-CoV-2 is the name of the coronavirus that causes the disease called COVID-19. The new vaccines are likely to be safe in humans because they do not contain killed or weakened SARS-CoV-2. Instead, researchers take a virus known to be safe in humans, such as a chimpanzee flu virus, and attach the genetic information on the spike protein from SARS-CoV-2. The immune systems of humans then make antibodies to kill the spike protein so that when people are exposed to SARS-CoV-2, their immune system destroys the spike protein so the virus cannot get into human cells.
• SARS-CoV-2 gets into human cells through a “key” called the ACE2 receptor.
• Scientists take just the part of SARS-CoV-2 spike protein that opens the ACE2 door to let them inside of human cells.
• They attach the “key” to another relatively harmless virus like a chimpanzee flu virus to make the vaccine.
• Then they give humans the vaccine with the attached “key” spike protein that lets the coronavirus into human cells.
• Then your immune system responds to the “key” by making antibodies against the “key,” not to other parts of SARS-CoV-2.
• When vaccinated humans are exposed to SARS-CoV-2, their immune systems make IgG antibodies that will destroy the “key” so the virus cannot get into human cells, and it dies instead of multiplying in the vaccinated person’s body.
Mass Production of the Vaccines
The next challenge will be producing and distributing the vaccines, once they are approved. The U.S. and many other countries have already started work on distribution, well before anyone knows whether the vaccines will work. For example, The Serum Institute in Puno, India, is already producing 720,000 doses per day of the Oxford vaccine, long before tests for safety and benefits have been completed (New York Times, August 1, 2020).
What This Means For Us
This current COVID-19 pandemic has spurred scientists to make major breakthroughs in which they can produce vaccines at an incredibly fast rate that was previously impossible. These vaccines made by attaching a part of SARS-CoV-2 to relatively harmless viruses appear to be safer and may even be more effective than many previous types of vaccines. If studies being done right now show effective protection against COVID-19, we should be able to start immunizations in late fall of 2020 and begin to gain herd immunity to stop this pandemic in 2021.
