Emerging new sub-variants of the coronavirus and waning population immunity are likely to lead to an increase in infections Covid-19 in the northern hemisphere - where Greece is also located - at the same time that the flu returns. That's what a number of scientists are predicting, now finding increasing evidence that the northern hemisphere has entered an exacerbating trajectory of Covid-19 for this fall and winter.
The new strains of the Omicron variant that more effectively evade immune defenses (vaccinal or natural after infection), the changes in the behaviors of many people (who no longer adhere to protective measures) and the increasing weakening of antibodies in the population as it passes time, are combined, with the result that many countries, as estimated, will soon again be faced with a large number of cases - and possibly hospitalizations - Covid-19.
But the new generation of updated vaccines that specifically target Omicron is hoped to put a damper on the new coming wave, according to the scientific journal Nature which explored future developments. However, the realization of these new vaccines Covid-19 it is happening at a relatively slow pace, while at the same time Omicron does not stop evolving and "giving birth" to new subvariants, which have begun to be found internationally and which may trigger a new wave in the coming months. An increase in hospitalizations is already being recorded in European countries.
For the time being, however, it is estimated - according to evolutionary biologist Tom Wenceleers of the Belgian Catholic University of Louvain - that the recent increase in cases is not so much due to these new strains of the coronavirus, as on the one hand to declining immunity, which now provides a short-term only protection against the possibility of infection, on the one hand the increased crowding of people without masks and keeping distances, to an extent approaching pre-pandemic levels.
Previous waves caused by Omicron sub-variants (BA.2, BA.4, BA.5) are receding, but evolutionary "descendants" of these sub-variants are now gaining ground, with new mutations helping them to spread. According to virologist Tom Peacock of Imperial College London, an unprecedented variety of new subvariants from different branches of the Omicron "tree" is being recorded. Some have drawn particular attention, such as BQ.1 (derived from BA.5 with additional key changes) which has shown rapid rise, BA.2.75 and the related BA.2.75.2 (which tend to dominate in India ) and BA.2.3.20 (which is growing rapidly in Singapore and has also appeared in Denmark and Australia).
"I'm pretty sure that at least one of these variants or a combination of them will lead to a new wave of infections, although ultimately it's not that important which one will bring the next wave, as they all behave similarly," Venceleers said.
All the new sub-variants carry multiple changes (mutations) in the spike protein with which the coronavirus penetrates and infects human cells, which explains why it is increasingly common for vaccinated people to become infected, especially if it has been a while since they had the vaccine. last dose. A Chinese study, led by immunologist Yunlong Richard Cao of Peking University, found that BQ1.1. (a member of the BQ.1 family with one extra mutation) and BA.2.75.2 are those with the greatest ability to evade neutralizing antibodies. "The degree of immune escape is amazing right now, crazy," Dr. Cao said.
Experts such as Venceleers initially estimate that the autumn-winter wave (or waves) will be similar in size - at least in terms of the number of cases - to the outbreak caused by BA.5. More difficult to predict is how hospital admissions will develop. Hospitalizations are expected to remain lower than in previous winters, but how much lower is unknown.
"Although it's a completely different game compared to 2020 and 2021, a new outbreak would probably be associated with an increase in deaths and hospitalizations," said infectious disease epidemiologist Justin Lesler of the University of North Carolina. He believes a strong re-emergence of the flu is likely after its near-extinction the past two winters, sparking fears of a double epidemic. Covid-19 and flu. If, indeed, this happens, then the hospitals and the health systems in general will be "pressured".
Booster doses with the new updated Omicron vaccines are thought to be likely to provide some protection against infection with the new subvariants, but not for long, according to the scientists. According to Kao, it will probably take two doses of these updated vaccines to develop high levels of neutralizing antibodies, specifically against Omicron.
Fortunately, all evidence suggests that vaccines Covid-19 -old and new- remain highly effective in preventing the risk of serious illness. That's why, he points out, countries' autumn-winter vaccination programs with booster/booster doses should prioritize those people who face the greatest risk of becoming seriously ill from the coronavirus, such as the elderly and people with chronic conditions.
Source: RES-EAP