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By Jerome H. Kim, MD
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There are few government initiatives that have a higher return on investment than vaccination. For companies that make vaccines the process from the laboratory into the clinic is long, expensive and complex. The process takes, on average, five to 10 years, costs $1 billion, and has a 90 percent failure rate.
COVID-19, however, will not give us the benefit of time. In 12 weeks it has spread to 198 countries, infected over 800,000 and killed more than 40,000.
As social distancing, lockdowns, postponed business meetings, and closed borders grind on, predictions of economic collapse with dramatic societal dislocation are now being made.
Without a vaccine, COVID-19 will continue to pose a threat to countries until roughly 60 percent of the population has been infected. In a country of 50 million, that would mean 30 million infections and 300,000 to 600,000 deaths.
With an effective vaccine, the impact of COVID-19 would effectively be blunted, and life, as it was prior to COVID-19, would be restored ― suggesting the question, "When will there be a vaccine?"
From a vaccine development perspective there are unanswered questions. First, we don't know whether a person can contract COVID-19 twice.
Immunity against a second infection suggests that, for a period of time, immune or defensive responses that defeated the first infection protect against a second ― the inspiration for a vaccine.
But second, we would need to know what those immune responses are ― the presence of proteins that neutralize the virus, virus-specific "killer" cells, or both?
Third, we would like to know that those immune responses protect animals against infection. Finally we don't know whether new vaccine candidates will be safe in humans.
These questions inform and guide vaccine development, and under usual circumstances, we have time to partially answer these questions. These, however, are not usual times.
Vaccine development proceeds in phases. Vaccines are created in a laboratory and tested in animals to see whether they protect against infection. Vaccines are tested to ensure safety in animals, and then enter Phase I testing in humans, where safety and a preliminary vaccine-induced responses are evaluated.
Successful candidates then enter Phase II, where a larger number of individuals in the "target" population are tested to ensure the desired immune responses are present.
Phase III tests a vaccine's ability to protect against infection and disease. Phase III data are pivotal for vaccine approval by a regulatory authorities, the Ministry of Food and Drug Safety in Korea.
Between each phase data are generated, collated and analyzed, and under normal circumstances, the five to -10 year timeframe accommodates this sequential approach.
In a pandemic, however, it is possible to shorten time to development. Phase I and II can be combined and run in an overlapping fashion. Decisions to proceed with subsequent phases might be made on the basis of immune responses after completion of the initial vaccination series.
Hence, we might know whether a vaccine protects against COVID-19 infection in 12 to 18 months. Then the vaccine would need to undergo an expedited regulatory review, and if approved, must be manufactured.
Because preparation for manufacturing can take one to two years, companies often build at risk to ensure rapid manufacturing after approval.
In the rush to a vaccine, we cannot ignore safety. Vaccines are given to the healthy to prevent, not cause, illness. Vaccine trials must be monitored closely by an independent body to ensure that participants suffer no ill effects from vaccination. Safety evaluation should continue for an extended period, to establish short-term and longer-term safety.
We need a vaccine against COVID-19, as a vaccine offers the best hope for a return to life as it was before the pandemic.
We should move quickly to fund and execute COVID-19 vaccine trials, and Korea's strong biotechnology and vaccine manufacturing companies should be at the forefront, working collaboratively to accelerate the development of a vaccine for COVID-19.
The writer is the director general of the International Vaccine Institute (IVI), a Seoul-based international organization devoted to the discovery, development and delivery of vaccines for global public health.
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