# COVID-19 Canonical page: https://carecard.ca/knowledge/immunizations-serology/covid-19 **Status:** Required for all students **Valid for:** Does not expire, but some sites require an up-to-date booster — check current policy. This page explains why the vaccine is required and how it works, using guidance from Health Canada and the Public Health Agency of Canada. It is educational and does not replace advice from your own health care provider or the specific rules of your program and placement site. See the [Source & references](#source--references) at the bottom. ## Why this is required [#why-this-is-required] As a medical student on placement you work where patients with COVID-19 are cared for, and you are in close contact with people who are at high risk of severe illness — older adults, newborns and patients with underlying medical conditions. The National Advisory Committee on Immunization (NACI) recommends COVID-19 vaccination for people at increased risk of exposure to SARS-CoV-2 or of severe disease, and specifically names **health care workers and other care providers in facilities and community settings**. Vaccination is an occupational infection-prevention measure that: * **Protects you.** COVID-19 vaccines give good protection against severe illness and reduce your chance of being infected on the job. * **Protects your patients.** Reducing your risk of infection lowers the chance that you pass SARS-CoV-2 to vulnerable patients. * **Keeps you working.** Fewer infections means fewer missed placement days and less disruption to the clinical team. Health Canada frames this under the ethical principle of *reciprocity*: because you may be asked to care for people with COVID-19, you should have access to measures — including personal protective equipment and vaccination — that protect you from infection and its complications. ## About COVID-19 [#about-covid-19] COVID-19 is caused by the SARS-CoV-2 virus, which spreads through the air on infectious respiratory particles produced when an infected person breathes, coughs, sneezes, sings, shouts or talks. The illness covers a spectrum from asymptomatic through mild, moderate, severe and critical disease, with severe outcomes more common with increasing age and in people with underlying medical conditions. One large Omicron-wave study estimated that about **1 in 3 infections were asymptomatic**, which is part of why the virus spreads so easily in health care settings. * **Symptoms Health Canada lists** include runny nose, sneezing, sore throat and headache, along with cough, fever, chills, muscle and joint pain, dizziness, gastrointestinal symptoms (nausea, diarrhea, abdominal pain), hoarse voice, and a new loss of or altered sense of smell. * **Long COVID (post-COVID-19 condition):** symptoms — often fatigue, shortness of breath and cognitive difficulty — that appear around three months after infection and last at least two months. Health Canada estimates about **16% of Canadians** with a confirmed or suspected infection go on to develop it. ## How the vaccine works [#how-the-vaccine-works] The COVID-19 vaccines used in Canada are mostly **mRNA vaccines** (Pfizer-BioNTech Comirnaty and Moderna Spikevax). Messenger RNA is essentially a recipe: it gives your cells the instructions to make the SARS-CoV-2 **spike protein**, the protein found on the surface of the virus. Your immune system learns to recognize that spike protein, so if you are later exposed to the real virus your body can respond quickly. The mRNA does not stay in the body and does not affect your DNA. ## How well it works [#how-well-it-works] * The original mRNA vaccines showed **over 90% efficacy** in clinical trials against symptomatic and severe disease from early strains of SARS-CoV-2. * Real-world effectiveness varies with the vaccine product, the interval between doses, the strains circulating at the time, and your age, health status and history of prior infection or vaccination. * Protection wanes over time — evidence suggests it drops after roughly **four to six months** — which is why staying up to date matters (see below). ## Safety and side effects [#safety-and-side-effects] Reactions are usually **mild or moderate and pass within a few days**: * Pain, redness or swelling at the injection site * Tenderness or swelling in the armpit * Fatigue, headache, muscle pain, joint pain, chills or fever Serious reactions are rare. Myocarditis and pericarditis (inflammation of the heart muscle or its lining) have been reported as rare side effects after mRNA vaccination and are being monitored by Health Canada's ongoing safety surveillance. ## Staying up to date [#staying-up-to-date] NACI describes eligibility in terms of **one or two doses per year** rather than fixed "spring" and "fall" doses, with a **minimum interval of three months** between doses. Health care workers may be advised to receive a dose each year to keep protection current. The COVID-19 vaccine can be given on the same day as the influenza vaccine. Confirm the schedule that applies to you with your program or a health care provider. ## What to submit [#what-to-submit] * An official vaccination receipt or record for each dose * The vaccine name, lot number and date of every dose * Your full legal name and date of birth ## Accepted proof [#accepted-proof] * Provincial vaccine receipt (e.g. the Ontario COVID-19 vaccine receipt PDF) * Pharmacy or clinic immunization record * International immunization card with an English translation ## Good to know [#good-to-know] * Download the PDF receipt directly — a screenshot of a QR code alone is often rejected. * Confirm every page shows your name. * Combine all doses into a single file when you can. ## Validity [#validity] Does not expire, but some sites require an up-to-date booster — check current policy. ## Source & references [#source--references] The medical information on this page is adapted from Health Canada and the Public Health Agency of Canada: * [Health Canada](https://www.canada.ca/en/health-canada.html) * [COVID-19 vaccines: Canadian Immunization Guide](https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-26-covid-19-vaccine.html) * [Immunization of workers: Canadian Immunization Guide](https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-3-vaccination-specific-populations/page-11-immunization-workers.html) * [Guidance on the use of COVID-19 vaccines for 2025 to summer 2026 (NACI)](https://www.canada.ca/en/public-health/services/publications/vaccines-immunization/national-advisory-committee-immunization-statement-guidance-covid-19-vaccines-2025-summer-2026.html) * [COVID-19 signs, symptoms and severity of disease: a clinician guide](https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/guidance-documents/signs-symptoms-severity.html) * [COVID-19 longer-term symptoms among Canadian adults (post-COVID-19 condition)](https://health-infobase.canada.ca/covid-19/post-covid-condition/) * [COVID-19 vaccine safety: side effects following immunization](https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19/vaccines/safety-side-effects.html)