Eastern Ontatio Health Unit / Bureau de santé de l'Ontario

Dr. Paul’s Vax Facts

If you haven’t been vaccinated yet, if you have concerns, if you have questions… we encourage you to read on. A series of articles about the COVID-19 vaccine will be shared here over the coming days and weeks.



Containing the Fourth Wave with Increased Rates of Fully Vaccinated Residents

We are now seeing local COVID-19 case numbers creep back up, officially bringing us into this fourth wave. The biggest difference between this wave and previous ones is the number of people that are vaccinated vs. unvaccinated and the presence of the Delta variant. 

As of September 8th, 2021, current data showed that 85% of eligible residents within the EOHU region had received at least one dose of a COVID-19 vaccine — while 78.3% were fully vaccinated. Data shows the majority of Ontarians facing severe outcomes related to COVID-19 are unvaccinated or only partially protected (Figure 1).

The first dose of the COVID-19 vaccine gives good, but only partial protection. The second dose is what will boost the first one to give optimal protection. We also know that the Delta variant responds well to the vaccine, but only after the second dose. Therefore, it is important to get the second dose.

Figure 1: Proportion of confirmed COVID-19 cases, hospitalizations (including intensive care unit admissions), and deaths among unvaccinated, partially vaccinated, and breakthrough (fully vaccinated) cases: Ontario, December 14, 2020 to August 7, 2021

Source: Ontario Agency for Health Protection and Promotion (Public Health Ontario). Confirmed cases of COVID-19 following vaccination in Ontario: December 14, 2020 to August 7, 2021. Toronto, ON: Queen’s Printer for Ontario; 2021.


The Second Dose Trifecta: Protection from Delta, Lower Severity of Illness & Decreased Hospitalizations

As with any immunization, when you receive a COVID-19 vaccine, protection from infection does not happen immediately. Immunity develops over time. The COVID-19 vaccine is very effective (60-80%) at preventing COVID-19 infection 3-4 weeks after receiving a single dose. Following the second dose, this protection increases (greater than 85%).

The vaccine has been shown to be effective against the Delta variant. This, however, is only true for individuals who have received two doses. Those who have received only one dose are still at great risk of infection. Fully vaccinated individuals (14 days after receiving the second dose) benefit from protection against the Delta and other currently known variants.

In the slight chance that COVID-19 cases occur in fully vaccinated individuals, the vaccines are shown to reduce the severity of illness, if symptomatic at all. This in turn reduces transmission because these breakthrough cases have a decreased viral load and are not shedding it as much.

Full vaccination offers substantial protection against severe health outcome needing hospital care. Unvaccinated people have a 30-fold higher risk of being in the hospital and 48-fold higher risk of being in the ICU compared to the fully vaccinated (Figure 1). Increasing the rate of full vaccination will help ensure hospitals don’t become overwhelmed.

Figure 1. Analysis: Secretariat of the Science Advisory Table (https://covid19-sciencetable.ca/ontario-dashboard/). Data: https://data.ontario.ca/ and CCM plus; estimates of patients in hospital and ICU are age standardized.

Source: https://covid19-sciencetable.ca/wp-content/uploads/2021/09/Update-on-COVID-19-Projections_2021.09.01_English-1.pdf


Breakthrough Infections: Still Benefitting from the Protection of the Vaccine

The COVID-19 vaccine is very effective at preventing infection; however, a small number of infections ‘break through’ among fully vaccinated individuals (14+ days since 2nd dose). This is known as breakthrough infection, which only 6.4% of all fully vaccinated individuals in Ontario have experienced.

Breakthrough infections are more commonly occurring among elderly populations and other vulnerable people with a lower immune response to vaccines. While it is possible and expected for some who are fully vaccinated to get COVID-19, this does not mean the vaccine doesn't work. Individuals experiencing a breakthrough infection are more mildly affected, still benefiting from the protection of the vaccine against severe outcomes.

Vaccines are most importantly intended to prevent severe illness, hospitalization, ICU admission and death. The COVID-19 vaccine is doing that very effectively, even in those who experience a breakthrough infection. Please don’t let the possibility of a breakthrough infection discourage you from receiving the vaccine.


Third Dose for Some: Does This Mean Two Doses Are Not Effective?

For most fully vaccinated individuals (two doses), the COVID-19 vaccine provides strong protection against illness and severe outcomes. However, a third dose is being offered to certain vulnerable populations who, compared to the general population, have a waning or a decreased immune response to the vaccine.

This does not mean that two doses are not effective. A complete two-dose COVID-19 vaccine series provides strong protection against COVID-19 infection and severe outcomes, including against the Delta variant of concern, in the general population.

Given the specific needs and circumstances of individuals in the identified vulnerable groups, a third dose will help to provide an improved immune response and decrease their risk of becoming a breakthrough case.

The recommendation for a third dose for individuals in these groups is to bring their level of protection up to the level that the general population gets from two doses. It is a response that will help safeguard the health of our region’s residents.


For the Kids: How Your Vaccination Protects Others Who Can’t

Without the COVID-19 vaccine, anyone who comes into close contact with someone who is infected is at risk of becoming infected themselves, and of potentially infecting others.

If a fully vaccinated individual (14+ days since second dose) comes into close contact with someone who is infected, their risk of becoming infected themselves, and of potentially infecting others is greatly reduced.

If they don’t become infected, then they will not spread it to others.

If they do become infected, they may be less likely to spread it to others because with most variants they will have a smaller amount of the virus present in their bodies and release less of it while they talk, exhale or do other normal daily activities.

Children under 12 years of age make up a large portion of the population who are not yet vaccinated. Those who are eligible and who do receive the vaccine, help stop the spread of COVID-19, protecting children and others who cannot be vaccinated themselves.


Achieving Herd Immunity Through COVID-19 Vaccines

Herd immunity happens once enough people are immune to a disease, making its spread unlikely. As more and more residents receive the COVID-19 vaccine, we come closer to achieving this.

Herd immunity even provides a layer of protection for those who cannot be vaccinated because the immune people weaken the potential chain of transmission, so the virus has little opportunity to spread within the community.

Unlike COVID-19 infection, COVID-19 vaccines create immunity without causing illness or resulting in severe disease, hospitalization, or death. We must continue to increase the rate of COVID-19 Vaccination Within the EOHU Population to achieve herd immunity.

The percentage of a population that needs to be vaccinated to achieve herd immunity depends on how contagious the disease is. The Delta variant is highly contagious, meaning that a greater proportion of the population needs to be vaccinated to stop the spread of COVID-19.


COVID-19 Vaccines: Your Concerns on Fertility, Pregnancy and Breastfeeding

Getting the COVID-19 vaccine is a safe way for people to protect themselves from severe illness. This includes people who are pregnant, trying to get pregnant, or might want to become pregnant in the future and their partners. There is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems in women or men.

The vaccine is safe and recommended for pregnant people because they are at higher risk of complications if a COVID-19 infection occurs during pregnancy. COVID-19 vaccines can also be safely given to breastfeeding people. Antibodies that a vaccinated pregnant or breastfeeding person makes are likely to pass on to the baby. This is safe for the baby and helps protect the baby from COVID-19.


Five Reasons to Receive the Vaccine

If you become infected, you may recover quickly, but some are more severely impacted. Here are five reasons to receive the vaccine.

  1. Vaccines are most importantly intended to prevent severe illness, hospitalization, ICU admission and death. The COVID-19 vaccine is doing that very effectively. Increasing the rate of full vaccination will help ensure hospitals don’t become overwhelmed.
  2. The vaccine is effective, even against the Delta variant for individuals who are fully vaccinated.
  3. In the small chance that a fully vaccinated person gets COVID-19, the vaccines are shown to reduce the symptoms and severity of illness. This in turn reduces transmission because, with most variants, they tend to have a smaller amount of the virus present in their bodies and release less of it while they talk, exhale, or do other normal daily activities.
  4. As more and more people receive the COVID-19 vaccine, we come closer to achieving herd immunity which happens once enough people are immune to a disease, making its spread unlikely.
  5. Unlike COVID-19 infection, the COVID-19 vaccine creates longer term immunity without causing severe disease, hospitalization, or death. If you have had COVID-19, the vaccine is still recommended. Natural immunity from COVID-19 infection may not last as long, making it possible to get it and spread it again.

Infection Causes Much More Serious Health Outcomes Than the Vaccine

COVID-19 Infection

Complications from COVID-19 infection can include serious conditions, like pneumonia or kidney failure and, in some cases, death. There is no specific treatment for COVID-19. The majority of COVID-19 cases are mild and most people who get it will recover on their own. However, an infected person can spread the virus to others who may be more vulnerable and more severely impacted.

Though most recover quickly, some people have symptoms for several months after having the COVID-19 infection. Long-term symptoms may include extreme tiredness, cough, shortness of breath, pounding heartbeat, dizziness, headaches, sore throat, fever, chest pain, joint pain, or rash.

Treatments like ivermectin are not effective and can be highly dangerous. Vaccines, however, are effective in helping to prevent serious health outcomes.

COVID-19 Vaccine

Some people may experience side effects from the vaccine, but these will likely be mild to moderate and resolve after a few days. The most common side effects include pain at the injection site, headache, tiredness, muscle or joint pain, chills and fever.

Severe allergic reactions are rare but can occur within 2 hours of vaccination. They include hives, swelling of the mouth and throat, trouble breathing, hoarseness or wheezing. Other serious side effects are very rare but can occur within days or weeks of vaccination. They include fever over 40˚C or 104˚F, flu-like symptoms, seizures or other unusual or unexpected events.

Ontario is not administering first doses of the AstraZeneca vaccine out of an abundance of caution due to a rare blood clotting condition after vaccination. Rare cases of myocarditis/pericarditis following mRNA vaccination have been reported. Investigations into the association between myocarditis/pericarditis and mRNA vaccines continue.

Bottom Line

The short-term side effects of the COVID-19 vaccine are less than the risk and potential long-term health damage caused by the COVID-19 virus. Long-term side effects are not expected with the COVID-19 vaccines. For the vast majority of people, side effects of the vaccine are mild or moderate and last only for a few days. They’re a normal sign that your immune system is working to build protection against COVID-19.


This concludes Dr. Paul's Vax Facts, a series of articles about the COVID-19 vaccine.

Eastern Ontatio Health Unit / Bureau de santé de l'Ontario