Should Singaporeans brace themselves for a bad flu season?
In the midst of warnings of a “tripledemic” in the United States and the United Kingdom, how concerned should Singaporeans be about influenza? According to Yvonne Su of Duke-NUS, now is the best time to get a flu vaccine.
SINGAPORE: It’s that time of year when everyone you know seems to be getting sick. Isn’t it, however, “just the flu”?
Since September, global influenza activity has been on the rise. The United States and the United Kingdom are bracing for bad flu seasons this winter, with health officials already reporting an earlier-than-usual increase in cases. They warn of a “tripledemic,” in which concurrent outbreaks of COVID-19, flu, and RSV (respiratory syncytial virus) will put additional strain on the healthcare system.
Should Singapore also brace itself for a bad flu season? According to Health Minister Ong Ye Kung, a new COVID-19 wave is expected around the end of the year.
In most places, influenza activity peaks during the winter months. In Singapore, influenza virus circulates all year, with two distinct peaks from May to July and December to February, coinciding with the rainy seasons.
Singapore’s influenza activity typically increases near the end of the year, as the December school holidays and festive celebrations such as Christmas and New Year’s tend to involve travel overseas or large group gatherings. Traveling to colder Northern Hemisphere destinations where influenza transmission is active may also result in people catching the flu and carrying the virus when they return.
On May 13, 2022, passengers walk through a transit hall at Changi Airport in Singapore. (AFP/Roslan Rahman photo)
Seasonal influenza is responsible for 290,000 to 650,000 deaths worldwide each year. According to studies, the hospitalization rate in Singapore is 50.1 per 100,000 person-years, but rates are higher in young children and the elderly over the age of 65.
RESPIRATORY ILLNESSES RETURN WITH A VIOLENCE
Experts have warned that once pandemic measures are lifted, common respiratory illnesses could resurface with a vengeance. Strategies such as aggressive testing, travel restrictions, lockdowns, and mask use were effective in preventing the spread of not only the coronavirus but also influenza and other respiratory viruses such as RSV.
During the COVID-19 pandemic, the number of influenza cases dropped dramatically, resulting in almost no human influenza virus circulation for more than two years. This, combined with lower influenza vaccination rates, is likely to have resulted in waning population immunity, making all of us more vulnerable as influenza strains resume global circulation.
Another reason could be the prevalent H3N2 subtype this time around. The seasonal impact of influenza varies according to the predominant strain. There are currently four influenza virus subtypes circulating among us: two subtypes of influenza A (H1N1 and H3N2) and two subtypes of influenza B. (Victoria and Yamagata).
H3N2 viruses have the highest mutation rate of the four. Influenza viruses, like the SARS-CoV-2 virus, are RNA viruses that mutate over time and generate new variants.
Influenza subtypes, like coronaviruses and their spike proteins, are distinguished by the hemagglutinin protein (such as H3 in H3N2), which binds to the cell to cause infection. Mutations in this protein can allow the virus to avoid detection by our immune system.
This means that the H3N2 strain in the influenza vaccine will need to be updated more frequently or risk losing effectiveness against currently circulating viruses.
VACCINES THAT WORK AGAINST INFLUENZA
The good news is that there are effective influenza vaccines available, known as quadrivalent vaccines because they contain – and thus protect against – all four subtypes of influenza.
However, due to the time required to manufacture the vaccines, the World Health Organization consults global scientific experts to determine the strains that will comprise the vaccine for the upcoming flu season – twice a year to recommend the composition for vaccines in the Northern and Southern Hemispheres. The vaccine’s effectiveness is affected by how well the vaccine strains match the circulating viruses.
This season’s H3N2 virus belongs to a genetic group or clade known as 3C.2a1b.2a2. Current vaccines for both the Northern and Southern Hemisphere influenza seasons (2022-2023) contain an H3N2 strain of this clade and should provide protection against circulating viruses – regardless of which flu vaccine your doctor stocks.
As we approach the holiday and peak travel seasons, flu shots can be administered two weeks before departure to allow our bodies to develop the necessary immune response.
Flu vaccine formulas must be updated on a regular basis due to mutating strains, and they currently provide only limited protection. JOE RAEDLE/AFP
WOULD YOU LIKE MORE INFLUENZA TESTING?
The pandemic has highlighted diagnostic testing as a critical tool in combating COVID-19 and has normalised self-testing. Given the availability of similar antigen rapid test (ART) kits for influenza, could more influenza testing be beneficial?
With COVID-19 now considered endemic, incorporating influenza diagnostic testing would be beneficial in determining whether the sick person is infected with flu, SARS-CoV-2, or both.
Knowing what virus is causing the illness can help doctors prescribe appropriate antiviral medications for treatment sooner, as some antiviral influenza drugs work best within 48 hours of symptom onset. Furthermore, early diagnosis and treatment can help to reduce the health burden, including disease complications and hospitalization rates.
It all comes down to cost and utility. Who would foot the bill for self-testing kits? Is it necessary to test everyone who exhibits symptoms of respiratory illness? If a healthy person is up to date on their flu and COVID-19 vaccinations, the illness will be mild and self-limiting if infected with either virus.
Comment: You should take more sick days, even if you work from home.
People believe they do not require a fourth COVID-19 vaccine shot. They are incorrect.
Testing could be better targeted at highly vulnerable groups, such as young children, the elderly, pregnant women, immunocompromised individuals, and people with chronic medical conditions, who face severe clinical outcomes if infected with influenza.
IN THE DIRECTION OF A COVID-FLU SHOT
The next critical question is whether different rules should be applied in COVID-19-positive cases versus flu-positive cases.
People with COVID-19 are currently advised to stay at home for at least 72 hours. People with flu are not given such instructions, though the hope is that they are responsible enough to stay home or at the very least wear masks after nearly three years of pandemic-heightened vigilance.
Is it necessary to continue testing every sick person if no additional preventive measures are required, whether from the flu or COVID-19? Early diagnostic and detection are critical from a scientific standpoint for monitoring any emerging novel variants and early signs of outbreaks so that additional preventive measures can be implemented quickly.
Commentary: New COVID-19 variants are now available. Should you be concerned?
Commentary: COVID-19 booster shots must be updated to accommodate newer variants.
SARS-CoV-2 and influenza will continue to circulate and evolve, and new variants will emerge. Currently, the flu and COVID-19 vaccines can be administered concurrently. A combined COVID-flu vaccine, which Pfizer and BioNTech are investigating, could be ideal, but more research is needed to answer questions about safety, side effects, and effectiveness.
Finally, getting a flu shot every year is a great way to protect ourselves and avoid serious illness, in addition to the good habits we’ve developed like washing our hands, wearing masks, and staying home when sick.
if you need to get a flu shot to protect yourself, you may visit clinic near me, Healthcare united Toa Payoh Clinic for the vaccination. Beside flu vaccination, we do have HPV vaccination like Gardensil 9. We do provide other services like GP consultation, Health Screening, and Medical Checkup. Have you done your annual Health Screening?