WEBVTT 00:00:06.674 --> 00:00:08.534 When a new pathogen emerges, 00:00:08.534 --> 00:00:12.204 our bodies and healthcare systems are left vulnerable. 00:00:12.204 --> 00:00:16.144 In times like these, there’s an urgent need for a vaccine 00:00:16.144 --> 00:00:19.492 to create widespread immunity with minimal loss of life. 00:00:19.492 --> 00:00:23.962 So how quickly can we develop vaccines when we need them most? NOTE Paragraph 00:00:23.962 --> 00:00:27.728 Vaccine development can generally be split into three phases. 00:00:27.728 --> 00:00:32.071 In exploratory research, scientists experiment with different approaches 00:00:32.071 --> 00:00:35.371 to find safe and replicable vaccine designs. 00:00:35.371 --> 00:00:39.211 Once these are vetted in the lab, they enter clinical testing, 00:00:39.211 --> 00:00:44.291 where vaccines are evaluated for safety, efficacy, and side effects 00:00:44.291 --> 00:00:47.116 across a variety of populations. 00:00:47.116 --> 00:00:49.556 Finally, there’s manufacturing, 00:00:49.556 --> 00:00:53.787 where vaccines are produced and distributed for public use. NOTE Paragraph 00:00:53.787 --> 00:00:59.287 Under regular circumstances, this process takes an average of 15 to 20 years. 00:00:59.287 --> 00:01:03.287 But during a pandemic, researchers employ numerous strategies 00:01:03.287 --> 00:01:06.027 to move through each stage as quickly as possible. NOTE Paragraph 00:01:06.027 --> 00:01:09.627 Exploratory research is perhaps the most flexible. 00:01:09.627 --> 00:01:12.617 The goal of this stage is to find a safe way 00:01:12.617 --> 00:01:16.932 to introduce our immune system to the virus or bacteria. 00:01:16.932 --> 00:01:21.392 This gives our body the information it needs to create antibodies 00:01:21.392 --> 00:01:24.062 capable of fighting a real infection. 00:01:24.062 --> 00:01:27.762 There are many ways to safely trigger this immune response, 00:01:27.762 --> 00:01:33.192 but generally, the most effective designs are also the slowest to produce. NOTE Paragraph 00:01:33.192 --> 00:01:37.342 Traditional attenuated vaccines create long lasting resilience. 00:01:37.342 --> 00:01:39.912 But they rely on weakened viral strains 00:01:39.912 --> 00:01:44.553 that must be cultivated in non-human tissue over long periods of time. 00:01:44.553 --> 00:01:47.994 Inactivated vaccines take a much faster approach, 00:01:47.994 --> 00:01:53.744 directly applying heat, acid, or radiation to weaken the pathogen. 00:01:53.744 --> 00:01:58.216 Sub-unit vaccines, that inject harmless fragments of viral proteins, 00:01:58.216 --> 00:02:00.466 can also be created quickly. 00:02:00.466 --> 00:02:05.001 But these faster techniques produce less robust resilience. NOTE Paragraph 00:02:05.001 --> 00:02:08.121 These are just three of many vaccine designs, 00:02:08.121 --> 00:02:10.651 each with their own pros and cons. 00:02:10.651 --> 00:02:13.631 No single approach is guaranteed to work, 00:02:13.631 --> 00:02:16.891 and all of them require time-consuming research. 00:02:16.891 --> 00:02:20.151 So the best way to speed things up is for many labs 00:02:20.151 --> 00:02:23.381 to work on different models simultaneously. 00:02:23.381 --> 00:02:25.681 This race-to-the-finish strategy 00:02:25.681 --> 00:02:29.938 produced the first testable Zika vaccine in 7 months, 00:02:29.938 --> 00:02:35.088 and the first testable COVID-19 vaccine in just 42 days. 00:02:35.088 --> 00:02:39.088 Being testable doesn’t mean these vaccines will be successful. 00:02:39.088 --> 00:02:42.208 But models that are deemed safe and easily replicable 00:02:42.208 --> 00:02:47.387 can move into clinical testing while other labs continue exploring alternatives. NOTE Paragraph 00:02:47.387 --> 00:02:51.896 Whether a testable vaccine is produced in four months or four years, 00:02:51.896 --> 00:02:56.932 the next stage is often the longest and most unpredictable stage of development. 00:02:56.932 --> 00:03:02.184 Clinical testing consists of three phases, each containing multiple trials. 00:03:02.184 --> 00:03:07.084 Phase I trials focus on the intensity of the triggered immune response, 00:03:07.084 --> 00:03:10.924 and try to establish that the vaccine is safe and effective. 00:03:10.924 --> 00:03:15.229 Phase II trials focus on determining the right dosage and delivery schedule 00:03:15.229 --> 00:03:17.449 across a wider population. 00:03:17.449 --> 00:03:19.939 And Phase III trials determine safety 00:03:19.939 --> 00:03:23.519 across the vaccine’s primary use population, 00:03:23.519 --> 00:03:27.837 while also identifying rare side effects and negative reactions. NOTE Paragraph 00:03:27.837 --> 00:03:31.987 Given the number of variables and the focus on long-term safety, 00:03:31.987 --> 00:03:35.987 it’s incredibly difficult to speed up clinical testing. 00:03:35.987 --> 00:03:39.397 In extreme circumstances, researchers run multiple trials 00:03:39.397 --> 00:03:41.777 within one phase at the same time. 00:03:41.777 --> 00:03:46.067 But they still need to meet strict safety criteria before moving on. 00:03:46.067 --> 00:03:49.917 Occasionally, labs can expedite this process by leveraging 00:03:49.917 --> 00:03:52.577 previously approved treatments. 00:03:52.577 --> 00:03:58.763 In 2009, researchers adapted the seasonal flu vaccine to treat H1N1— 00:03:58.763 --> 00:04:03.776 producing a widely available vaccine in just six months. 00:04:03.776 --> 00:04:08.267 However, this technique only works when dealing with familiar pathogens 00:04:08.267 --> 00:04:11.897 that have well-established vaccine designs. NOTE Paragraph 00:04:11.897 --> 00:04:16.560 After a successful Phase III trial, a national regulatory authority 00:04:16.560 --> 00:04:21.102 reviews the results and approves safe vaccines for manufacturing. 00:04:21.102 --> 00:04:25.782 Every vaccine has a unique blend of biological and chemical components 00:04:25.782 --> 00:04:29.492 that require a specialized pipeline to produce. 00:04:29.492 --> 00:04:32.392 To start production as soon as the vaccine is approved, 00:04:32.392 --> 00:04:37.754 manufacturing plans must be designed in parallel to research and testing. 00:04:37.754 --> 00:04:42.086 This requires constant coordination between labs and manufacturers, 00:04:42.086 --> 00:04:46.905 as well as the resources to adapt to sudden changes in vaccine design— 00:04:46.905 --> 00:04:50.605 even if that means scrapping months of work. NOTE Paragraph 00:04:50.605 --> 00:04:54.435 Over time, advances in exploratory research and manufacturing 00:04:54.435 --> 00:04:56.835 should make this process faster. 00:04:56.835 --> 00:04:59.445 Preliminary studies suggest that future researchers 00:04:59.445 --> 00:05:03.335 may be able to swap genetic material from different viruses 00:05:03.335 --> 00:05:06.105 into the same vaccine design. 00:05:06.105 --> 00:05:11.159 These DNA and mRNA based vaccines could dramatically expedite 00:05:11.159 --> 00:05:13.819 all three stages of vaccine production. 00:05:13.819 --> 00:05:15.949 But until such breakthroughs arrive, 00:05:15.949 --> 00:05:19.943 our best strategy is for labs around the world to cooperate 00:05:19.943 --> 00:05:22.743 and work in parallel on different approaches. 00:05:22.743 --> 00:05:24.983 By sharing knowledge and resources, 00:05:24.983 --> 00:05:28.785 scientists can divide and conquer any pathogen.