It’s been almost
four years since the first human cases of COVID-19 infection caused by
SARS-CoV-2 were reported.
Though the global health
emergency was declared over on May 5, 2023, COVID-19 remains a major public
health threat. As we enter the fall/winter respiratory virus season, it’s a
good time to review current COVID-19 risks and recommendations.
What are the
current COVID subvariants in circulation?
The dynamically
evolving nature of SARS-CoV-2 represents a major hurdle for vaccine scientists.
Omicron XBB.1.5 was the globally dominant subvariant during the first half of
2023, one which led to the development of the updated mRNA vaccines.
However, the
predominant subvariants circulating in the United States, United Kingdom,
European Union and Canada at the time of writing include Omicron subvariants
EG.5, FL1.5.1, XBB.1.16, XBB.1.9 and XBB.2.3.
Do they cause
serious illness?
The capability of
currently circulating subvariants of SARS-CoV-2 to cause serious illness
appears similar to that of other Omicron lineages, including XBB.1.5. The main
risk factors for developing more than just a mild respiratory tract infection
include increasing age, immunosuppression, cancer, pregnancy and the presence
of chronic medical conditions.
The predominant
strains of SARS-CoV-2 in circulation in fall 2023 are Omicron subvariants.
(NIAID), CC BY
Comorbidities such
as diabetes, obesity and diseases of the lungs, heart, liver, kidneys and
neurologic system are all risk factors for hospitalization, critical illness
and death due to COVID-19.
In adults, the
odds of dying with COVID-19 increase by approximately three- to six-fold with
obesity and four-fold with pulmonary disease. In children, the odds of dying
increases by about 63-fold with obesity, 20-fold with Down’s syndrome and
1.4-fold with asthma. In adults with COVID-19 infection, men are almost twice
as likely to die as women.
Long COVID (also
known as post COVID-19 condition) is one of the most discussed complications of
SARS-CoV-2 infection. However, it is rare in children and adolescents without
chronic health conditions. Furthermore, vaccination does not appear to prevent
long-COVID in children.
Is there a
possibility of a fall surge in COVID-19 cases?
In contrast to
pandemics, which are global in nature and involve sustained virus transmission,
outbreaks are time-limited and geographically restricted.
During the last
three respiratory virus seasons in the U.S. and Europe, COVID-19 transmission
patterns were somewhat reminiscent of seasonal influenza. The fall/winter
outbreaks of COVID-19 were characterized by a sudden increase in infection
rates above the baseline pandemic level.
These
observations, along with recent wastewater surveillance and clinical data,
suggest that a spike in hospitalizations and deaths from COVID-19 is likely to
occur this fall and winter.
Are current
vaccines protective?
In September 2023,
policymakers in the U.S., the U.K., Canada and the EU announced the approval of
updated COVID-19 mRNA vaccines.
These “next
generation” products were formulated to target the XBB.1.5 subvariant.
Unpublished pre-clinical studies that led to regulatory approval have
demonstrated these vaccines to be safe and efficacious in all age groups.
The astonishing
ability of the virus to mutate at every given opportunity has made it extremely
challenging for scientists to develop a vaccine that offers long-term
protection. The XBB.1.5 subvariant now accounts for only two to five per cent
of circulating SARS-CoV-2 viruses, and is on the verge of becoming extinct.
Newer circulating subvariants such as EG.5 possess novel mutations that may
reduce the effectiveness of vaccine-mediated immunity.
What are the
current vaccine recommendations?
Recommendations
for the updated vaccines vary according to country/region, vaccine product,
presence of chronic health problems, age and history of prior COVID-19
vaccination or infection.
Public health
authorities in Canada, the U.K. and the EU have strongly emphasized the need to
prioritize vaccination for those at highest risk of illness, including those
providing essential community services.
In contrast, the
U.S. Food & Drug Administration has provided the general public with
vaccine recommendations that are not risk-stratified.
Dosing guidelines
for these newer vaccines are summarized in the table below:
How can I protect
my health?
In addition to
vaccination, standard infection control practices are recommended at all times
to prevent the acquisition and transmission of respiratory tract viruses such
as SARS-CoV-2. These measures include staying at home when ill, wearing a
surgical or N95 mask in crowded indoor areas and frequent hand-washing.
Research evidence
supports a non-universal vaccination strategy that focuses on high-risk
individuals. Healthy children and adolescents are low-priority candidates for
COVID-19 vaccination according to the World Health Organization and renowned
experts.
The mortality rate
for unvaccinated children under the age of 18 years is around 1/400,000, with
most deaths occurring in those with comorbidities. Therefore, parents and their
children should consult with their health-care provider for personalized
recommendations.
Public health
messaging for vaccine-preventable illnesses often ignores other
health-promoting activities such as regular physical exercise, a healthy diet,
restful sleep and avoidance of harmful substances (smoking, alcohol, illicit
drugs). These lifestyle practices can improve and protect health, but are not a
substitute for vaccination.
What if I’m
hesitant about getting a vaccine?
Research has
clearly shown who is at greatest risk of developing severe COVID-19 illness, and
who stands to benefit most from vaccination. Yet, misinformation may
compel some
high-risk individuals to avoid vaccination altogether.
These doubts may
be fuelled by a perceived lack of transparency of governments and the
pharmaceutical industry. In these instances, a shared decision-making approach
involving patients and their trusted health-care providers is recommended to
dispel any myths about vaccines.
Source:Econotimes
Date:2023-10-06