2020 Vision to Pandemic Proof our Health and Future
As we turn the page on the challenging year that was, we yearn for brighter days ahead. The prospect of a return to “life as it was” is, however, unlikely to be a near term reality. Indeed, when the virus known as SARS-CoV2 was unleashed upon the world from Wuhan, China, late in 2019, we could not have imagined that our lives would be forever changed. But such it has. With nearly 82 million individuals having been infected with SARS-CoV2 globally, COVID-19 has claimed 1.8 million lives to date and over 15,500 in Canada alone. The carnage cannot be wholly captured in the tally of lives lost. The indirect costs are immeasurable. The enormous impact of lockdown and quarantine measures on our society and economy will be felt for generations to come. The mental health toll and other indirect effects of COVID-19 on our healthcare systems must be considered an urgent sub-crisis. Despite the pain and loss, there is reason for hope and even some silver linings. We have learned to appreciate a simpler life, enjoyed more time with family and by necessity adopted new measures and technology to thrive despite the need for distance and restrictions. Local Matters A pandemic anywhere is a problem everywhere. But the dynamics vary greatly depending on local factors. In Canada, the per capita COVID-19 infection and death rates have varied by province due to differences in population demographics as well as varying approaches taken by the provincial governments and varying adoption rates of public health measures. Figure 1: Count of total cases by province as of December 30th, 2020 Vaccination Nation As of January 1st, Canada has two approved mRNA COVID-19 vaccines. Despite Health Canada’s authorization and the federal government’s procurement efforts, the process to get vaccine doses into arms has been bogged down by inefficiencies and delays. In Israel, vaccination centres are open 24 hours, 7 days a week with no break for holidays or even the Sabbath. Enhanced access and a coordinated distribution and communication strategy have allowed more than 1 in 10 Israelis to have received their first dose of vaccine to date. Canada by comparison, as of December 30th, had vaccinated only 99,559 or 2.6 per 1,000 people. Figure 2: Cumulative Vaccination Rates per Capita, from December 13th, 2020 to January 1st, 2021 On December 9th, Health Canada authorized Pfizer-BioNTech’s mRNA COVID-19 vaccine. Two weeks later, Canada became the second country in the world after the US to approve a second mRNA vaccine developed by Moderna. The Government of Canada has invested over $1 billion to secure access to approximately 400 million doses of promising vaccines, including 40 million doses of the Moderna vaccine and up to 76 million doses of the Pfizer vaccine. However, at present, Canada has administered less than 25% of its current supply of approximately 400,000 doses. Over two weeks has elapsed since the first dose was administered in Ontario on December 14th, yet only 29,000 doses have been administered here. At this rate, it is unlikely that most Canadians will have access to a first dose of the vaccine before summer. Even those at highest risk are facing unacceptable delays in accessing vaccines. Every day of delay risks lives. Canada has announced a three tiered prioritization approach to distribute the vaccine based on the NACI guidance (see Figure 3) released in November which identifies key populations for early COVID-19 immunization including; those at high risk for severe illness or death, front-line health care workers and other essential workers, the elderly (starting with those above the age of 80 years) and those living in marginalized communities including the Indigenous population. Figure 3: NACI guidance on priority populations for immunization mRNA Vaccines 101 The mRNA vaccines produced by Pfizer-BioNTech and Moderna are the first of a new generation. Messenger RNA technology however is not new. Synthetic single strand genetic code has been developed for therapeutic use over the past thirty years predominantly as a cancer therapy but more recently to vaccinate against RNA viruses. Within a week of Chinese researchers first publishing the genetic sequence of the novel coronavirus, a team of researchers at the University of Pennsylvania began to develop synthetic mRNA to target the virus’ outer shell, the spike protein. Both Moderna and Pfizer licensed this formulation to create vaccine candidates. At unprecedented speed, within 66 days of the sequencing of the SARS-CoV2 genome, Moderna had announced a vaccine and began US clinical trials. mRNA Vaccines and Immunity These novel vaccines work by instructing the cell to develop an antibody response in the same way that infection would illicit immunity. The vaccine contains a strand of genetic code (RNA) that has been synthesized to enter the cell, but not the nucleus. The vaccine RNA, which contains the code for viral spike protein, is then translated by the cell into proteins. Vaccine RNA works in the cytoplasm and cannot combine with DNA of the human host genome which is contained within the nucleus. The proteins encoded by the RNA represent only those found on the viral envelope and thus are unlikely to result in symptomatic disease associated with infection, namely COVID-19. Because the spike protein plays a critical role in infecting a host’s lung cell (via the ACE-2 receptor) they are ideal targets for vaccines. Digging into Vaccine Data The clinical studies evaluating these mRNA vaccines were designed to show efficacy against symptomatic disease, COVID-19 rather than infection. Symptomatic disease is defined as having recognized symptoms of COVID-19 including respiratory symptoms, fever, or loss of smell or taste AND a positive RT-PCR test confirming the presence of viral RNA. Moderna’s trial looked at outcomes in three groups: those over the age of 65 years, those between the ages of 18 to 65 years with risk factors and those between the age of 18 to 65 years without risk factors. Pfizer-BioNTech’s trials included those aged 16 years or older. Notably, neither vaccine has been studied or is approved for use in children under 16 years or women who may be either pregnant or breast feeding. Both vaccines have shown excellent efficacy of about 95% after a second dose as measured at 7 days by Pfizer and 14 days by Moderna. The Moderna vaccine has been shown to be 100% effective in preventing in severe COVID-19 disease defined by severe symptoms requiring hospitalization and/or resulting in death. While both of the mRNA vaccines require a second dose, the timing of this second dose differs, as shown below (see Figure 4). The immunity achieved with just one dose has not been confirmed but early indications suggest that it may be as high as 90% at 4 weeks following the first dose. For this reason, with limited vaccine supply governments are grappling with the decision of whether to hold back a second dose (as is presently the protocol in both the US and Canada). Some experts have called for a first dose to be made available to as much of the population as possible. The two mRNA vaccines are developed from the same genetic code but with different formulas (see Figure 5). Adverse reactions have occurred only rarely with either vaccine; rare allergic reactions have been reported with Pfizer’s vaccine and immune reactions have been reported with the Moderna vaccine including tender, enlarged lymph nodes under the arm injected. Those who have had a confirmed infection should defer immunization, until symptoms resolve. Some experts suggest deferring immunization for 90 days from the time of infection or from the time monoclonal antibody therapy or convalescent serum was administered. The vaccine should not be combined or given simultaneously with any other vaccine but rather given at least 2 weeks apart. Presently, it is unclear whether these vaccines will play a therapeutic role in an active infection. Figure 4: Comparing the approved mRNA COVID VaccinesPfizer-BioNTech | Moderna | |
Technology | mRNA to spike protein | mRNA to spike protein |
Dose Schedule | 2 doses at 21 days | 2 doses at 28 days |
Volume per dose | 30mcg | 100mcg |
Efficacy | 95%, 7 days after 2nd dose | 94.1%, 14 days after 2nd dose |
Age Approved | 16 years and older | 18 years and older |
Storage | -75c, special handling required | -20c or in the fridge for up to 30 days |