What does the percentage of vaccine effectiveness mean on the road back to a post-covid-19 world?
After months of walking on eggshells wondering where we can travel to, who we can be with, and fears of indoor gathering and being around others, many of us yearn for normal.
The headline of deaths, hospitalizations, and a second coming of the covid19 virus is a daily occurrence. Will the vaccine solve all of this and if we take it, what does 95% effectiveness actually mean?
Which vaccines are coming to the market in the USA?
Currently, there are three vaccines including the two mRNA ones by Pfizer and Moderna which use newer technology. A third by Astrozenica is claimed to be 70 percent effective using a weakened virus and is cheaper to administer. Johnson and Johnson are in their third phase of testing and should announce effectiveness numbers shortly.
Vaccines can significantly shorten the road back to normal by helping those who have not been infected or exposed to develop vaccine immunity. This is different than natural immunity in that those who were not exposed can receive the vaccine and be protected from the virus. It is believed that vaccine immunity reduces community risk and helps people avoid the ramifications of an infective agent.
While questions about the safety of the vaccines are on the minds of many, China has also developed and disseminated vaccines to their public even though those vaccines are still experimental according to CNN. Russia claims their vaccine is 92% effective on smaller group trial sizes Countries such as Brazil and UAE have placed orders for the Chinese vaccines and Rumania may use the Russian Sputnick vaccine.
Vaccine vs. natural immunity.
If you have already been exposed and have had antibodies develop, the vaccine may not be necessary as you already have immunity, and reports of reinfection are rare. You may also have developed immunity from other coronaviruses which may explain why many people had exposure but no symptoms and also no antibodies.
Most of the vaccines will require a primary injection and then a second dose (booster) a month or so later for maximum effectiveness.
If you receive a vaccine that is 95% effective, it means that during testing, those who received an actual vaccine vs. a placebo had developed antibody immunity.
For vaccines to work, as they have done with mumps or rubella or polio, a large enough portion of the population must be inoculated (had an immune response or developed immunity after exposure). Once enough people develop immunity, the virus will basically burn itself out as it cannot find any more hosts to infect. It is for this reason that vaccination programs want broad participation of the population. The more people who vaccinate, and then become inoculated, the faster the virus can go away through herd immunity, the masks can come off, and the faster we find a new normal.
The NY Times recently offered excellent explanations of what effectiveness means in their recent article. Check it out below
2 Companies Say Their Vaccines Are 95% Effective. What Does That Mean?
You might assume that 95 out of every 100 people vaccinated will be protected from Covid-19. But that’s not how the math works.
By Carl Zimmer Nov. 20, 2020
The front-runners in the vaccine race seem to be working far better than anyone expected: Pfizer and BioNTech announced this week that their vaccine had an efficacy rate of 95 percent. Moderna put the figure for its vaccine at 94.5 percent. In Russia, the makers of the Sputnik vaccine claimed their efficacy rate was over 90 percent.
“These are game changers,” said Dr. Gregory Poland, a vaccine researcher at the Mayo Clinic. “We were all expecting 50 to 70 percent.” Indeed, the Food and Drug Administration had said it would consider granting emergency approval for vaccines that showed just 50 percent efficacy.