Omicron's BA.4 and BA.5 sub-variants are responsible for the spike in cases.
Ontario and Quebec are at the start of a new wave of COVID-19. The situation is much different than last summer, but some basic advice remains just as valid. Here's the straight-forward on wearing a mask, using self-tests, vaccination, and the risks of reinfection.
Right now, BA subvariants .4 and BA.5 from Omicron are responsible for the increase in the number of cases. These subvariants are much more contagious than those seen since the start of the pandemic.
The reproduction number (R0) of the original strain of the COVID-19 virus (Alpha) is 3.3, which means that one infected person infects approximately three others.
Someone who is infected with BA.4 or BA.5 infects an average of 19 people. These variants are therefore as contagious as measles, the virus that was once considered the most contagious in the world.
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It is still too early to say for sure if these subvariants cause more severe symptoms.
Some analyzes show that they are no more severe than those of other Omicron strains, but a Japanese study (not peer-reviewed) shows that they seem to reproduce better in the lungs than other variants from Omicron. This suggests that they could lead to more serious complications than other Omicron subvariants. Moreover, in several countries, the number of hospitalizations and deaths is increasing.
Is this increase caused by a more virulent strain or by a very high number of infections? The answer is not yet clear.
This is why experts are keen to remind that even though the authorities have lifted most restrictions and obligations, the virus has not disappeared. It is therefore necessary to be vigilant and careful.
Without tests, it is not possible to distinguish with certainty whether the symptoms are those of COVID-19 or those of another disease infectious.
Even with these new subvariants, rapid self-tests are still very effective in determining whether a person – asymptomatic or not – has a high viral load and, therefore, whether they are contagious at the time of testing.
< p class="e-p">Home self-tests can detect infections even in asymptomatic people.
When should you get tested? When you have symptoms or when you want to check your contagiousness before visiting a vulnerable person.
Remember that you have to rub the swab against the inside of both cheeks, then against the back of the tongue, before performing the two rubs in each nostril.
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The results of a self-test are good for a few hours. You can get a positive result the next day, hence the importance of testing yourself a few times.
An infected person – especially if they have been vaccinated – can get a positive result a few days after the onset of symptoms. This is why, if you have been in contact with an infected person or if you have symptoms similar to those of COVID-19, you must continue to test yourself for a few days and wear a mask in public, as a precautionary measure.
In Quebec, a person is entitled to a box of five free self-tests per month; they are available in pharmacies. In Ontario, five free tests per family are offered at some pharmacies and grocery stores.
The presence of a colored band – even a very faint line – indicates a positive result. The risks of a false positive result are very slim.
The intensity of the color of the strip does not indicate whether you are highly or slightly contagious. It only indicates whether you are contagious or not.
The result is positive? Since public health is almost no longer tracing contacts, we must try to notify people we have recently encountered. These people may be on the lookout for symptoms, a gesture that can help stop the chain of transmission.
In Quebec as well as in several other provinces and territories of Canada, public health recommends that an infected person (including those without symptoms) self-isolate at home for five days. No grocery store, no restaurants; we don't show up to work and we don't take public transport.
Remember that the Government of Quebec requires that an unvaccinated person who is in contact with an infected person isolate themselves even before having received a positive test.
If a member of family is positive, other members of that family should test themselves for a few days. Pending confirmation of the results of these tests, as a precaution, it is recommended that these people wear a mask in public.
The rules state that a person can be released from self-isolation after five days to do essential activities if symptoms improve and they have been fever-free for 24 hours without taking fever medication. /p>
However, you must continue to wear a mask for five additional days.
Why? It is that after five days, many people continue to be contagious. The absence of symptoms after a few days does not guarantee that you are no longer contagious.
This analysis from Harvard University and MIT indicates that approximately half of people infected with Omicron (regardless of their vaccination status) are still infectious after eight days.
A another study observed that 80% of infected people still had a positive result after five days; same thing in 61% of cases after 10 days.
Do you absolutely have to go back to work or leave the house after five days? Wear a mask at all times (preferably a KN95 or N95 mask), reduce contact (especially with vulnerable people), and avoid crowded places (eg: festivals, restaurants, etc.).
KN95 masks offer better protection than cloth and surgical masks.
Wearing a mask is no longer required in most public places. However, public health authorities and health experts strongly recommend wearing one in certain circumstances:
on public transport;
in closed and crowded places;
in healthcare establishments;
While non-medical (cloth) masks can help prevent the spread of COVID-19, medical masks and respirators (N95/KN95) offer better protection, especially against the highly contagious subvariants that are circulating.
Surgical masks are 95% effective at filtering out virus particles, compared to just 37% for cloth masks, according to a study by Yale and Stanford universities.< /p>
Do you gather indoors? Improve ventilation by opening a door or window for a few minutes every hour or turning on your kitchen hood and bathroom fan.
A reminder regarding outdoor gatherings. #x27;outdoors: transmission of the virus is less frequent outdoors, but not impossible, especially if you are close to an infected person.
SARS-CoV-2 is transmitted not only by large droplets when sneezing or coughing but also by exhaled aerosols when talking or singing. Thus, the virus can remain suspended in the air we breathe for several minutes or even hours, like second-hand smoke.
At the start of the pandemic, the reinfections were rare. Authorities estimated that an infected person was protected for about 90 days and it was believed that one infection could offer the same protection as one dose of vaccine.
However, since the arrival of Omicron, due to its many mutations, this is no longer the case, as the newer sub-variants – and especially the BA.5 – are more successful in escaping the virus. ;natural or vaccine immunity.
Yes, an infection makes it possible to acquire a certain immunity. However, this is generally shorter than vaccine immunity and does not protect against other circulating subvariants.
Researchers at Imperial College London have shown that a person infected with Omicron acquires almost no natural immunity against the virus. This, the researchers say, puts people at risk for re-infection ad nauseam.
In this context, a recent infection is not the equivalent of one dose of vaccine. Immunity acquired through vaccination is preferred.
If we talk a lot about the fourth dose, we must remember that 45% of Quebecers have not yet received their third dose (or booster dose).
Why receive a third dose if the Government of Quebec continues to consider as adequately vaccinated those who have received two doses of vaccine? Because the number of antibodies produced by the immune system decreases over time.
The booster dose does not prevent infection, but it does allow the immune system to restore sufficient antibody levels to prevent serious complications from an Omicron infection. Antibody counts quickly rise to an adequate level one to two weeks after receiving the booster dose.
The fourth dose is currently recommended for people who are more vulnerable or at risk complications from COVID-19, but it should be remembered that in Quebec, it is available to all adults who wish to obtain it. The only condition: wait three months since an infection or a last dose before going to get a new dose.
These tips were developed with the help of Dr. Anne Bhéreur, family physician in palliative care, Matthew Oughton, infectious disease specialist and assistant professor in the Department of Medicine at McGill University, and Nimâ Machouf, consultant in infectious disease epidemiology and responsible for course at the School of Public Health of the University of Montreal.