As of July 15, the world has seen three workable Covid-19 vaccine candidates – Moderna, SinoVac and the Russian Vaccine – already in clinical trials. Given how recently the COVID-19 pandemic began spreading, it might seem promising that there’s already a lot of activity on the immunization front.
You ask: if medical experts say these coronavirus vaccines has been successfully developed, when exactly are they ready to go?
We all have read from the internet that a vaccine takes at least 12 to 18 months before finally reaching the production stage. Theoretically, this can be true. But not always.
The mumps vaccine—considered the fastest ever approved—took four years to go from collecting viral samples to licensing a drug in 1967. For Ebola, a vaccine took five years to develop.
American biotech company Moderna reportedly would enter the final stage of human trials for its COVID-19 vaccine on July 27, with 30,000 participants in the US. Half of them will get the vaccine at 100 microgram dose levels, and the other half to receive a placebo.
The clinical trial will run until October 27.
China's SinoVac is also set to start its final stage of tests. Russian researchers have completed all three clinical trials of their vaccine, though they have yet to share their data.
So, realistically, how long will it really take for us to see a Covid-19 vaccine up and ready to go inside the Philippine market?
Let's talk about the standard US vaccine procedurals. Phases 1 and 2 are done, so we'll count from Phase 3 onwards.
Phase III Vaccine Trials
Successful Phase II candidate vaccines move on to larger trials, involving thousands to tens of thousands of people. These Phase III tests are randomized and double blind and involve the experimental vaccine being tested against a placebo (the placebo may be a saline solution, a vaccine for another disease, or some other substance).
One Phase III goal is to assess vaccine safety in a large group of people. Certain rare side effects might not surface in the smaller groups of subjects tested in earlier phases. For example, suppose that an adverse event related to a candidate vaccine might occur in 1 of every 10,000 people. To detect a significant difference for a low-frequency event, the trial would have to include 60,000 subjects, half of them in the control, or no vaccine, group. (Plotkin SA et al. Vaccines, 5th ed. Philadelphia: Saunders, 2008)
Vaccine efficacy is tested as well. These factors might include 1) Does the candidate vaccine prevent disease? 2) Does it prevent infection with the pathogen? 3) Does it lead to production of antibodies or other types of immune responses related to the pathogen?
Next Steps: Approval and Licensure
After a successful Phase III trial, the vaccine developer will submit a Biologics License Application to the FDA. Then the FDA will inspect the factory where the vaccine will be made and approve the labeling of the vaccine.
After licensure, the FDA will continue to monitor the production of the vaccine, including inspecting facilities and reviewing the manufacturer’s tests of lots of vaccines for potency, safety and purity. The FDA has the right to conduct its own testing of manufacturers’ vaccines.
Post-Licensure Monitoring of Vaccines
A variety of systems monitor vaccines after they have been approved. They include Phase IV trials.
Phase IV Trials
Phase IV trial are optional studies that drug companies may conduct after a vaccine is released. The manufacturer may continue to test the vaccine for safety, efficacy, and other potential uses. (Website: The History of Vaccines, "Vaccine Development, Testing, and Regulation")
Vaccines for the Philippines
Even after a working Covid-19 vaccine is finally out, it still takes time to mass-produce and distribute it across the globe. The world population is at 7.8 billion and, by history, no pharmaceutical company has ever produced such huge number of vaccines. The typical mass production count, at best, is somewhere between 500 million to 1 billion units. That is why the world hopes to see more vaccine candidates to succeed.
Then comes the cost. The means to develop the Covid-19 vaccine and the results of its clinical trials will determine how much it will cost to make the drug and who can afford it. Experts say delivering the vaccines could cost substantially more than traditional varieties and this might affect the world's poorest people. Thus, cooperation between leaders of countries is important to allow a COVID-19 vaccine to swiftly transfer its potency across the seas, particularly the Philippines.
What to do for now
In the meantime, the most valuable thing a person can do while waiting for the vaccine is to follow the minimum health protocols set by the authorities. For now, the use of face masks, social distancing, avoiding crowds and washing the hands regularly is still the best way to keep safe and avoid getting the infection.
Any thoughts?
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