Will there be waves of COVID-19 this fall and winter?

There is growing evidence that the Northern Hemisphere is responding to a surge
in COVID-19 cases this fall and winter.
Scientists say the new immune evasion strain, behavioral changes and reduced immunity of the SARS-CoV-2 Omicron variant mean that many countries may soon see a large number of COVID infections
.

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Author: Kope

Justin Lessler, an infectious disease epidemiologist at the University of North Carolina at Chapel Hill, said other factors on the horizon could spell trouble
.
The launch of the new "trivalent" booster is "a bit slow," Lessler said
.
There are now subtle signs that Omicron is evolving and producing a new variant of immune evasion
.
"As we enter the fall and winter, this could lead to some uplift," he said
.

Are new variants available?

 01 

Probably not yet, says
Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium.
The current increase in SARS-CoV-2 infection may be mainly due to a decrease in people's immunity , which provides a transient period of protection against infection and an increase
in mixing between people.
Health officials say social dynamics in many countries, including the UK, have returned almost to pre-pandemic levels
.
Factors that contribute to the growth of other respiratory viruses in colder months, including the extra time spent indoors, may also be at play
.

As the Omicron subvariants (BA.
2, BA.
4, and BA.
5) that drive past waves fade, the evolutionary offspring of these lineages are acquiring mutations that appear to be helping them spread
.

Researchers are paying close attention to certain sublineages
.
For example, the UK and some other European countries are witnessing the rapid rise
of BQ.
1 (a descendant of BA.
5, with several key changes).
In India, the BA.
2.
75 variant that triggered the infection wave a few months ago is now laying more eggs than all the others, said microbiologist Rajesh Karyakarte, the Maharashtra coordinator
for SARS-CoV-2 sequencing in Pune.
Of the samples his team sequenced in late September, a subvariant called BA.
2.
75.
2 was the most common (followed by close relatives
).
Another BA.
2 branch, BA.
2.
3.
20, developed rapidly in Singapore and emerged
in Denmark and Australia.

big will the autumn and winter waves be?

 02 

According to preliminary estimates, the size of the fall-to-winter wave will be similar to the BA.
5 surge, at least in terms of the number of infections
.
More difficult to predict is the impact on
hospitalization.
Researchers say vaccinations and the build-up of immunity in populations caused by previous infections could make hospital admissions lower than past waves of COVID-19, but it's unclear how low
.
"While the game is completely different from 2020 or 2021, the surge may still be related to an increase in the number of deaths and an increase in hospitalizations," Lessler said
.

But even a relatively mild wave of COVID-19 can put pressure on hospitals, which face backlogs and other conditions that place a heavy burden on
health systems during the winter months.
The flu has barely registered over the past two winters and could make a comeback in the Northern Hemisphere this season, raising concerns about
the flu and COVID-19 "twins.
" "During a year of severe flu, the hospital system became very tense.
"

What about the new vaccine?

 03 

Enhancers, including novel bivalent vaccines against the Omicron lineage, may provide some protection against infection with emerging variants
.
But scientists say that may not last long
.
Part of the bivalent vaccine is based on the Omicron subvariate, BA.
1 in the UK-approved vaccine and BA.
5
in the US.
But there are indications that vaccines tend to stimulate the production of neutralizing antibodies that best recognize progenitor viruses, and the first vaccines are based on ancestral viruses rather than Omicrons
.
A second dose of these vaccines may be needed to produce high levels of Omicron-specific neutralizing antibodies
.

Fortunately, all the evidence suggests that the COVID-19 vaccine is still very effective in preventing serious diseases, which Nuzzo believes should be the main goal
of countries' autumn and winter strengthening programs.
That means stepping up campaigns will focus on those at highest risk of serious illness, including the elderly and those with underlying health conditions, who benefit the most from the
extra protection.

Resources:

This article is intended to introduce medical research advances and cannot be used as a reference for
treatment options.
For health guidance, please visit a regular hospital
.

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