SINGAPORE - The demand for flu vaccines has spiked in the past few months, as people look to safeguard their health with the looming winter flu season, and as travel gradually resumes.

Doctors and infectious diseases experts here have been encouraging people to take the flu vaccine even though the number of influenza cases remains low, so as to guard against a possible "twindemic" of Covid-19 and the flu.

Even as countries battle the coronavirus pandemic, another viral wave caused by influenza not only threatens to overwhelm stretched healthcare systems, but it is also much more likely to kill those unlucky enough to catch both viruses.

Locally, the number of influenza cases has remained low, with polyclinics seeing fewer than half the number of patients seeking treatment for acute respiratory infections (ARI) compared with the same period last year.

According to the latest statistics from the Ministry of Health's Weekly Infectious Disease Bulletin, there was a daily average of 1,038 patients seeking treatment for acute respiratory infection (ARI) from Sept 27 to Oct 3, versus 2,619 cases last year.

But among those who had sought treatment for ARI, the number of patients with influenza-like illness was below 5 per cent, and the number of those who tested positive for influenza has remained at zero since June.

This is likely a result of mandatory mask wearing, safe distancing and enhanced personal hygiene, coupled with less travelling this year, said doctors here.

Dr John Cheng, head of Primary Care and Family Physician, Healthway Medical Group, said: "In Singapore, the flu season tends to arrive during the cooler periods between December and February, and between May and July, which coincides with the Northern Hemisphere and Southern Hemisphere winter epidemics, as well as the conventional peak travel seasons."

Hence, with notably fewer travellers coming in and out of the country, along with the safeguards taken by the public, the flu's chain of transmission is thus reduced during this period, he added.

Despite this, Dr Cheng has seen a 40 per cent increase in people getting flu vaccines in August and September, compared to the same period last year, as many are "becoming more conscious about their overall health and well-being".

Medical director of Parkway Shenton Edwin Chng said that this was also the case for the chain's clinics, with there being a 40 per cent increase in the demand for vaccines between July and October, compared to last year.

"Many people are hoping to stay well and healthy by taking the flu vaccine, as it gives them some sense of security, especially since there's no vaccine currently available for Covid-19," he said, noting that further economic reopenings and the anticipation of general travel resuming could account for the increased demand.

Likewise, Dr Asok Kurup, an infectious diseases specialist at Mount Elizabeth Hospital, said he has seen a 10 to 20 per cent increase in interest for flu vaccines, which could be largely attributed to increased education and awareness of public health, a spillover effect from the Covid-19 crisis.

"Especially with all this talk about a Covid-19 vaccine, people are more well-informed of the need to take precautionary measures to safeguard their health from infectious diseases which are preventable," he said.

Dr Chng anticipates that the demand for vaccines will continue to increase in the coming months, especially with enhanced subsidies for the influenza vaccine from November.

Singaporean adults can get higher subsidies of between $35 and $125 for nationally recommended vaccines under the National Adult Immunisation Schedule.

According to the schedule, one dose of influenza vaccination is recommended annually or every flu season, particularly for vulnerable groups, such as individuals with chronic illnesses, young children, seniors and pregnant mothers.

Hence, Dr Chng noted that doctors have been "more proactive" in recommending flu vaccinations, particularly for patients of high-risk groups.

"By reducing the spread of the virus, which have symptoms similar to Covid-19, it helps to reduce the noise interfering with diagnosing the Covid-19 virus,'' he said.

Dr Cheng added that "in the absence of a Covid-19 vaccine, we should continue to safeguard our health by protecting ourselves against vaccine-preventable illnesses''.

"With the flu vaccine, individuals are also protected against the possibility of being infected with both influenza and Covid-19 at the same time. If this were to occur, the fatality rate would greatly increase."

According to an article published by The Guardian on Sept 22, a study conducted in the United Kingdom among a group of 58 people found that 43 per cent of those co-infected with flu and Covid-19 had died, versus 26.9 per cent who had tested positive solely for Covid-19.

Respiratory viruses tend to thrive in cold climates, as people gather in crowded indoor environments, which facilitates the transmission of the virus.

Fearing the possibility of flu and other respiratory illnesses circulating over the winter period, the UK government bought 30 million doses of flu vaccine, with priority given to the elderly and those with pre-existing medical conditions for immunisation.

Infections in the UK have reached record levels with more than 17,000 new cases reported on Thursday (Oct 8), and Europe alone has reported 96,996 new cases - the highest total for the region recorded by the World Health Organisation (WHO).

Professor Dale Fisher, a senior consultant in the division of infectious diseases at the National University Hospital, said that, in winter, temperate countries tend to experience a higher incidence of influenza.

"So the major concern is that these European countries, as well as the United States, will experience this in addition to the Covid-19 problems, which in itself is stressing the healthcare system," said Prof Fisher, who is also the chair of WHO's Global Outbreak and Alert and Response Network.

"However, since the mitigation measures for Covid-19 transmission also prevent flu, countries with poor implementation of Covid-19-relevant interventions are therefore likely to suffer this twindemic, making health systems very at risk," he added.