Top health officials say the end of this year would be a best case scenario. But scientists have never created a vaccine so quickly, and there’s no guarantee any under development will ultimately work.
Worldwide, testing recently started or is about to start for about a dozen potential vaccines. The most promising vaccine candidates are expected to move into larger tests this summer.
How quickly those studies can determine whether the vaccines are safe and effective depends in part on how widely the coronavirus is still spreading. The studies will need to enroll 20,000 people or more for each vaccine candidate, with half of them getting the real vaccine and the rest getting a dummy shot. Then it’s a matter of waiting to see how many in each group become infected with the virus.
Answers will come faster if volunteers are recruited in places where outbreaks are worsening, a trend that can be hard to predict.
One way to speed up distribution is to start manufacturing doses before test results are in. But it’s a gamble that could mean throwing away tons of vaccines that fail.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.