Most people think of influenza as a seasonal sickness. But in Thailand, the severity of this common complaint is getting more aggravating each year.
Statistics from the Bureau of Emerging Infectious Diseases, under the Minister of Public Health's Department of Disease Control, show that in 2003, Thailand saw more than 43,000 suffering from H1N1 seasonal influenza, with zero deaths.
Only eight months into 2015 and there have been more than 43,000 cases of seasonal influenza across the country, with 24 deaths reported.
"People who suffer from influenza often suffer from severe symptoms such as high fever, body ache and fatigue," explained infectious medicine specialist Dr On-Umar Banpamai. "In some cases, complications are fatal."
Given the fact that influenza is likely to result in hospitalisation or even death, with approximately 250,000 to 500,000 people dying globally, according to the World Health Organization (WHO), an influenza vaccine has been promoted by healthcare practitioners around the world.
"In the United States, for example, there are campaigns encouraging people to receive the flu vaccine regardless of age and gender," said Dr On-Umar.
But one problem which stems from the vaccine is that people still fall victim to the disease even after being vaccinated, making many feeling sceptical about its efficacy and cost-effectiveness. But all this, said paediatric infectious disease specialist clinic professor Emeritus Sanay Chearskul, is caused by the fact that the flu vaccine only covers three different flu viruses, leaving one strain uncovered.
"There are three influenza virus strains: A, B and C," he said. "The C strain does not have any epidemiological significance because it hardly leads to the disease. The A strain with the H1N1 and H3N2 subtype is the most important one given it is responsible for most outbreaks. The influenza B virus has two lineages: the Victoria and Yamagata."
For years, flu vaccines were designed to protect against only three different flu viruses, namely influenza A H1N1, influenza A H3N2 and one B virus. But whether it is the Victoria or Yamagata to be added into a certain lot of vaccine to be used in a specific year depends on an agreed-upon discussion among 141 National Influenza Centres around the world, which is based on physical examination and data collection from patients worldwide.
This means the vaccine did not protect against the entire group of B viruses, said Dr Sanay.
"During the past decade, both influenza virus B Victoria and Yamagata lineages were responsible for flu outbreaks," he added. "Therefore, if the vaccine does not cover both lineages, the chances that people who get a shot would still get the flu are high."
Since 2009, studies and research have been conducted about the benefits of adding another B virus to the vaccine. And eventually the quadrivalent flu vaccine, or the shot that protects against four different flu viruses, namely two influenza A viruses and two influenza B viruses came into existence.
Since 2012, the WHO has promoted the quadrivalent flu vaccine. In the US, of the 151-156 million doses of influenza vaccine projected to be available for the 2014-2015 season, manufacturers estimate that 76 million doses will be quadrivalent flu vaccine, according to figures from the Centre for Disease Control and Prevention.
In Thailand, however, the shot was introduced for the first time last week at a private hospital in Bangkok. The vaccine is not available in public hospitals, yet.
Like the vaccine that covers three flu viruses, this new shot is not a one-off injection. "Those who get injected are still advised to be vaccinated regularly. The duration of protection can be five-six months or up to a year depending on each individual," explained Dr On-Umar.
The new vaccine is not 100% effective. But according to Dr On-Umar, the quadrivalent protection is relatively more powerful especially when compared to the previous type.
"The trivalent flu vaccine [which covers three viruses] is reported to have 50-70% effectiveness in protecting people against influenza," said the doctor. "The quadrivalent vaccine yields an additional 18% efficacy to the previous type."
Basically anyone above the age of six months who is healthy can get the flu shot. Those with severe allergies to egg, however, cannot get the injection because the ingredient is used during the manufacturing process of the vaccine.
"Speaking of the egg allergy criteria to get the flu shot, the bottom line is, if you can eat scrambled eggs the vaccine is safe for you," said Dr Sanay.
"Also you must not have a fever on the day you are to receive the shot," he continued. "In case you have a cold without fever, then you can take the injection. But it is always advisable that you inform your physician before you get the shot."
Severe side effects from the vaccine are rare, the most common one being redness around the injected area. Only 3% of those receiving the vaccine develop a fever which does not last long.
The body will be immunised against the flu viruses from seven to 14 days after the infection, added Dr Sanay. Some might need a booster shot in four weeks, especially those below the age of eight.
But getting the flu shot does not mean putting a lid on other measures against the infection. Universal precautions such as quality sleep, regular exercise, a stress-free life and healthy eating habits are still a good way to shield yourself against seasonal flu.
"To protect yourself against influenza viruses, wash your hands frequently especially when touching shared objects," advised Dr Sanay. "This is because the virus outside the body can stay alive on hard surfaces for hours. Also stay at least a metre away from flu-infected patients and frequently clean the areas around them with disinfectant. Good health is also crucial as it may lower the severity of the symptoms should you be infected."
"For patients, avoid going to public places," concluded Dr On-Umar. "Separate your eating utensils from others' and always wear a face mask if you cough or sneeze because the virus can go as far as 2m away from you. In most cases, patients suffering all types of flu will recover in five to seven days after symptoms develop, even without medication but only when the body's immune system gets stronger."
