From Mark Levine, the Doc with Pink Tights
In follow-up to last month’s article, today I am writing about vaccines. I must confess this is a subject that I don’ know a lot about. COVID-19 is a nasty virus from the corona virus family. It likely came from a bat virus and then made the jump to humans.
What is a virus? A virus is an infectious agent (germ) so tiny that it can’t even be seen with a microscope. It consists of genetic material in the core, surrounded by a protein shell. It cannot reproduce on its own and needs a host to do this.
What happens is that the virus will stick to a human cell and then the virus’s genetic material is injected inside. The virus then uses the machinery inside the human cell to reproduce itself. The next generation of viruses (babies) then leave the cell and infect other cells.
Currently there is no effective treatment for COVID-19. Hence, the mainstay of the fight against the pandemic is a strategy of social distancing, testing for the virus and tracing contacts. The hope is that a vaccine will be available soon to prevent the virus from infecting people.
What is a vaccine? A vaccine is a substance that stimulates the production of antibodies and provides immunity against an infectious agent. This means that the human body sees the infectious agent as something foreign and eliminates it. There are two kinds of vaccines: live attenuated and inactivated.
Live attenuated vaccines are produced by modifying a disease-producing virus in a laboratory, so that it is very weak and no longer infectious. For example, the vaccines for measles and small pox in Canada are live vaccines. When a person is inoculated, they get a very mild infection. As a result, they build up immunity, i.e. their immune system is programmed such that if they are later exposed to measles or small pox, the immune system recognizes the virus as foreign and destroys it.
An inactive vaccine is made up of a whole virus or piece of a virus that has been inactivated in the laboratory by heat, radiation, or a chemical substance. Inactivated vaccines are not alive and cannot grow in a person. In general, inactivated vaccines are weaker than live vaccines and often require re-inoculation with a booster dose.
There are more than 100 laboratories around the world working on a vaccine for COVID-19. Our lives have been turned upside down by the pandemic. A vaccine is being touted as the only hope for mankind. No doubt, we are all drinking the Kool-Aid because we want the pandemic to be over and we want to get back to normalcy.
How do we respond when leaders enthusiastically talk about the potential for a vaccine? Recently, Prime Minster Justin Trudeau described in glowing terms a collaboration between a Chinese company and a Canadian team in Halifax that is beginning to test a vaccine. Operation Warp Speed has been launched by U.S. President Donald Trump to have a vaccine in production by the end of the year.
I respond with a healthy amount of skepticism, tempered with some hope. Vaccines can often take several years to make in the lab. Sometimes, scientists fail at making them, such as in the case of HIV.
Once a vaccine is created, it needs to go through a very careful testing program to ensure that it works and is safe. It undergoes testing in animals and then human volunteers. The vaccine is then tested in large clinical trials in which some people receive the vaccine and some do not. Finally, the vaccine production is scaled up on a massive basis so that populations can be vaccinated. Countries usually do not market vaccines. Often a big pharma company buys the rights to produce the vaccine and market it.
I am fearful that there is so much hype and competition between countries and companies to find a vaccine that steps in the usual process will be shortened or even skipped, thus potentially jeopardizing safety. We must rely on our government regulatory agencies to ensure this does not happen.
How do I answer the question “when will a vaccine for COVID-19 be available?” My answer: “I don’t know. Perhaps 12 to 24 months.” But I hope sooner.
