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Your questions answered: the path to an effective COVID-​19 vaccine

June 9/2020

On May 26, 2020, IHPME hosted a COVID-19 webinar — the twelfth in the DLSPH COVID-19 webinar series — exploring the path to an effective COVID-19 vaccine. It featured leaders from research, policy and private industry describing the pharmaceutical trajectory of new antiviral products (including the COVID-19 vaccine), from development through to testing and launch.

Watch the COVID-19 Webinar: Understanding COVID-19’s economic impact on DLSPH YouTube.

Vaccination is the cornerstone of public health and medicine. Over the last 50 years, vaccines have saved more lives than almost any other health measure and are crucial to preventing devastating infectious diseases, such as measles, polio, pertussis and — optimistically — COVID-19.

As the world anxiously waits for a COVID-19 vaccine, this webinar highlighted the University of Toronto’s rich history in vaccine production and distribution that it shares with the Connaught Laboratories (now Sanofi Pasteur).

Click here to learn more about the history of vaccines & public health at U of T

Professors Vivek Goel (Vice-President, Research and Innovation, and Strategic Initiatives, U of T), Jeff Kwong (Interim Director of the Centre for Vaccine Preventable Diseases) and Terry Sullivan were joined by IHPME Senior Fellow Mark Lievonen (former President of Sanofi Pasteur Limited) to explore what vaccine-makers have learned from past infectious disease scourges and describe the process behind an effective vaccine.

With more than 30 questions asked, panelists were unable to answer every one. Professor Kwong has addressed some of the unanswered questions – check out his Q&A below (please note that some of these questions are paraphrased from the Zoom webinar Q&A).

I understand the urgency of developing a COVID-19 vaccine, but I’m concerned about the vaccine not being tested long enough to truly know the adverse effects and long-term effects if it were to come to market next year. How would you address these fears?

Clinical trials are designed to detect vaccine adverse events that occur at a frequency of one in 1,000. Adverse events that occur less frequently or have delayed onsets may not be detected in clinical trials and will only be detected after the vaccine is used in the general population through what we call post-marketing surveillance studies (also known as Phase 4 studies).

Vaccine safety is a top priority of both vaccine manufacturers and public health officials, and the safety of a vaccine is closely monitored around the world for years after its release. While it is natural to be worried about potential adverse effects of a vaccine, one must weigh the potential risks of a COVID-19 vaccine against the benefits of protecting oneself against COVID-19 infection and its associated complications.

During the H1N1 pandemic, how long did it take before an FDA-approved vaccine came out?

During the 2009 pandemic, the H1N1 virus was identified in April and a vaccine was released by October, which was obviously very quick, but that timeline was possible because of our extensive experience making seasonal influenza vaccines and the existing infrastructure to manufacture mass quantities.

Developing a vaccine against a novel pathogen is much more challenging and therefore it is expected to take much longer to develop a vaccine against SARS-CoV-2, the virus that causes COVID-19.

Are there any concerns over the efficacy of a potential vaccine in individuals with comorbidities such as diabetes and cardiovascular disease? Is it more challenging to develop a vaccine for a disease that effects vulnerable populations such as older adult so much differently than others?

Drawing from what we know about influenza vaccines, a substantial body of literature suggests that these vaccines are less effective among older individuals and those with certain chronic medical conditions that can suppress the immune system. Specifically which chronic conditions lead to reduced vaccine effectiveness is less clear.

Manufacturers have tried to develop influenza vaccines that are more “immunogenic” by adding adjuvants (compounds designed to boost the response of the immune system to a vaccine) or increasing the “antigenic content” of the vaccine (a larger dose of antigen will induce a stronger immune response). Researchers will evaluate vaccine effectiveness in various age and risk groups.

Are there shortcuts in testing and developing a vaccine, and if so, can you comment on the risks that might need to be assumed?

Typically there are no shortcuts. There are usually three phases of clinical trials involving increasing numbers of trial participants before a vaccine is released, after which there is ongoing monitoring of safety and effectiveness.

Interestingly, for some COVID-19 vaccine candidates, the Phase 1 and Phase 2 trials are being conducted concurrently, so that might be seen as a “shortcut” of sorts. Hopefully that will save a bit of time without sacrificing the ability to properly evaluate the safety and effectiveness of the vaccine.

Professor Kwong pointed out the challenges in the use of data for H1N1 and that we’re still experiencing the challenges using merged multi-province level data, as well as logistical and legislations barriers for many other databases for health services research. Any comments about a Federal-level platform for COVID-19 vs. province level infrastructure for data collection and use of data?

In Canada, health is generally considered a provincial responsibility, so I anticipate data collection for a COVID-19 vaccine will be a responsibility of provincial governments. The main issue in Ontario is not data linkage, but data collection – comprehensive and timely collection of data on the administration of the COVID-19 vaccine into immunization information systems will be critical for studies of vaccine safety and effectiveness.

Ideally, digital methods are used to collect these data, but if paper patient consent forms must be used, creative methods of data entry such as scannable forms can still be used to ensure efficient capture of this information in immunization information systems.