A woman being tested for Covid-19 in an adapted center in Helmond (North Brabant, Netherlands) on July 25, 2022 ©BelgaImage
Since mid-September, the Covid figures have been rising. According to the latest epidemiological bulletin from Sciensano, cases are up 26%, hospitalizations by 28%, deaths by 42%, and intensive care bed occupancy by 32%. In short, if the figures are still low compared to the waves already crossed, the lights are all red.
It was expected, autumn being conducive to the return of diseases such as Covid or the flu, but the population had time to forget which health rules were in force. A little reminder is therefore in order. To complicate the deal, there is an additional problem: now, it is the BA.5 version of the Omicron variant that is circulating. In Belgium, it represents 92.37% of cases according to Sciensano. Should we adapt our prevention rules in view of the characteristics of this newcomer (for barrier gestures, tests, quarantines, etc.)? We take stock.
When do you become a high-risk contact?
For the moment, the health rules enacted on the official Info-coronavirus website are still those dated March 2022, when the first versions of Omicron were essential in our country. Since then, a high-risk contact has been defined as a person six years of age or older who has come into contact with an infected individual for more than 15 minutes and less than 1.5 metre.
Why make such a distinction at six? According to Yves Van Laethem, interfederal Covid-19 spokesperson, “it would be purely linked to the fact that we did not do tests in very young children except in the case of serious pathology“, he confides to us. It would not be linked to the particular profile of BA.5.
What if you are a high risk contact?
The recommendations distinguish between contacts of this kind within the family home or outside. If your high-risk contact was outside the home, you just have to be careful for seven days (limitation of contacts, barrier gestures and teleworking, but no PCR test or quarantine) except for people with fragile health. Whether your contact was made in the family home but you have no symptoms, the recommendation is the same. You can possibly do a self-test, especially if you are not wearing a mask, and if it is positive you can ask for a code on www.masanté.be to do a PCR or antigen test in the pharmacy. Finally, if you are a high-risk household contact with symptomsyou go immediately to the PCR or antigen box in the pharmacy, with preventive isolation before the test is carried out.
Yves Van Laethem specifies that these distinctions between intra- and extra-family backgrounds come from the idea that overall, contacts are closer and longer within the same household. This is not a question related to the intrinsic risk of the type of contact, nor a desire to reduce the use of tests, according to him. He clarifies that this advice is specifically given for Covid and not for other respiratory diseases, although the disease is “becoming commonplace“. With Omicron and BA.5,”we are no longer in the mood to say ‘vade retro satanas’ as soon as a person sneezes or coughs at a party“, he says.
Which symptoms should alert with BA.5?
To assess its symptoms, the Info-Coronavirus site lists these potentially warning signs of a case of Covid: cold, headache, fever, loss of taste and smell, body aches, breathing difficulties, fatigue and diarrhea. A self-assessment is also possible on www.masanté.be, then indicating whether or not a test is required.
Yves Van Laethem recalls in passing that “with BA.1 and BA.2, perhaps also a little with BA.5, we are with a virulence five to eight times lower compared to the variants from Wuhan, Alpha and Delta“. The characteristics of Omicron would explain this trend but only in part. It should also not be forgotten that the vaccine also plays in the reduction of the overall risk, then “the most fragile have already been victims in previous years by the Covid“. All of this played a role in the lull in the epidemic. The other side of the coin: “Omicron is more transmissible, probably because it likes the top of the lungs better than the bottom“.BA.5 has proteins that can give it some nuances but the profile is also not totally different compared to BA.1 and BA.2, the first sub-variants of Omicron.
When to do a test exactly?
Now you may be wondering when it would be best to get a test to have the best chance of it being correct, whether you are asked to do one or not, especially following a high-risk contact. For Yves Van Laethem, “as soon as the symptoms are presentwe can consider that a test can be done“. In this specific case, a negative test “has a high predictive power and tends to show that you have caught another virus“.
For asymptomatic who learn that they have had contact with a positive person, the virologist advises to act in two stages. During the first 48 hours following this contact, it is better to take the first precautions, for example not to visit people in fragile health, or even wear a mask at work. “After 48-72 hours, you can possibly do a test even if you don’t have any symptoms. If it turns out negative, I’ll pretend nothing happened. Perhaps, despite everything, the symptoms might appear followingwards” and that it was a false negative, but he judges that the balance of risks is low and that it is possible to release the pressure.
Yves Van Laethem also reassures on one point: there is no noticeable drop in the effectiveness of the tests with BA.5. “I was never told that Omicron escaped the tests more than the others“, he says.
What regarding quarantines?
If you are positive for Covid, it is at least seven days of isolation from the precise moment of your test, “or from the onset of symptoms“, specifies the interfederal spokesperson Covid-19. Once you have reached the end of this period, you can end the quarantine provided you have not had a fever for at least three days and notice an improvement in other symptoms. You will also have to ensure absolute respect for barrier gestures (indoor mask, limitation of contact, especially no activities without a mask, avoid seeing people in fragile health, etc.) If you still have strong symptoms, isolation continues.
Does this mean that following having complied with all these rules, one can live without the slightest fear of infecting someone with BA.5? “Not 100%“, assure Yves Van Laethem. “Omicron have a rather short incubation and sometimes a slightly longer persistence. I think following a fortnight it’s fine, but not following 10-11 days“. In this sense, the 14-day quarantine, which was imposed for a time, would be more suitable to protect oneself more calmly from BA.5. However, the virologist specifies that this rule no longer exists for two reasons: one must take take into account the harshness of this duration for a population that is fed up with the Covid, but also the economic impact of such a measure in view of the number of quarantines necessary.
And for the vaccine?
There remains the question of the new bivalent vaccine which is currently used for the second booster dose. Immunological studies show that the bivalent allows “to produce more antibodies once morest Omicron“, recalls Yves Van Laethem. Recently, doses adapted to BA.5 have appeared but the virologist specifies that there have not yet been clinical studies really testing the effectiveness once morest BA.5, which is a sub -variant too recent to have precise data on this subject.”The BA.5 bivalent should not be inferior to the BA.1 bivalent, but is it superior? We do not know“.
Finally, the epidemiological projections predicted that the fall wave of BA.5 to come should be rather well contained if at least half of the over-65s were vaccinated. But this is already the case. 62% of over 65s received the second booster, as did 63% of 75-84 year olds and 55% of 65-74 year olds (same for 32% of 55-64 year olds). This reassures Yves Van Laethem, even if he hopes that the vaccination campaign will continue in view of his role which he considers “essential”.
©IPM Graphics
However, he recalls that these percentages are at the national level. At the regional level, the picture is somewhat different. Only 38% of Walloons and 23% of Brussels residents aged 65-84 have received the second reminder so far (compared to 72% on the Flemish side). For those over 85, these percentages are 37% in Wallonia, 30% in Brussels and 76% in Flanders. This is why as it stands, the virologist does not rule out a stronger resumption of the epidemic in the south of the country, even if there is still time to vaccinate and the projections are quite optimistic for to say that the wave of this end of the year should not be as high as the previous autumns.
