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Vaccines: Busting the myths and laying out the science

Vaccines: Busting the myths and laying out the science

Close to a year into the pandemic, vaccines seem to be on everyone’s mind. It is nothing short of a tremendous feat that we now have not just one but three approved vaccine candidates either already deployed or preparing to be deployed around the world. Taking into context the standard vaccine (or drug) development timeline of ca. 5-10 years, it speaks to the brilliant abilities of scientists when able to work singularly towards one goal, have the funding available and the political will in place for science to succeed.
However this dichotomy of the “usual” vaccine timeframe and the 10 month COVID19 vaccine development timeframe has resulted in some murmurs of mistrust in certain sections of society across the world. Furthermore, the advent of the mRNA vaccines and the novel technology associated with it compared to previous vaccine platforms have also contributed to the same. Vaccines are the predominant method by which we can tackle this pandemic which is now stepping into its 2nd year. If we are to have any hope of getting back to a “normalcy” and saving millions of lives, widespread immunity through vaccine inoculation is essential. As such, we at oDoc have prepared a short primer to address your most pressing questions about the COVID19 vaccines currently available.

Part 1: were the vaccines rushed?

Short answer: no safety steps were cut.

Long answer: The drug development process is made up of several steps: 1) a preclinical trial 2) a clinical trial which is broken down into a) Phase I b) Phase II and c) Phase III.

Preclinical stage is about deciding on the desired effect of the drug and getting initial information on its efficacy and safety. The vaccine candidate is tested inside test tubes (in vitro) and in animals (in vivo). Of 100 drugs tested usually only about 32 moves to the next stage. That’s a high level of failure so it’s often hard to find financing for this phase.

The three phases of the clinical stage have different objectives. Phase 1 is about assessing the safety and tolerability of the drug in a small group of healthy people (usually has a 75.1% success rate). Phase 2 is designed to test efficacy of the drug and continue safety testing in a larger group of people (this has a 50% success rate). 

Finally, Phase 3 which follows the gold standard format of trials, the randomised control trial with a large group of volunteers (ca. A few thousands usually but in the 40-50,000 range for the COVID19 vaccines) split into a placebo or control group and the vaccine candidate group. These trials are expensive, time consuming and difficult to run and aim to evaluate the risk-benefit of the drug across a cross section of the target population. 

None of these steps were cut for any of the COVID19 vaccines. As it’s a pandemic and this disease is everywhere and because there is political & economic will to develop a vaccine – there were plenty of volunteers ready to be enrolled into trials and plenty of funds ready to be invested into the process. Both of which resulted in a rapid development process and enabled the deployment of the vaccines for emergency use as early as January 2021. If anything, we can be encouraged that if the money & interest were there, science could move much faster than it currently does.

Part 2, do the vaccines work and are they safe?

Short answer: Detailed studies taking place over ca. 9-10 months have shown them to be safe and effective in the fight against COVID19. Not only did the authorised vaccines reduce the chance of falling sick from COVID19 but they all seem to prevent death and hospitalisation! 

Important to note that none of the vaccines injects COVID19 into the body. No major reactions were seen in the trials since April 2020 or in the 200 million vaccinations made in the real world since December 2020. Minor side effects from vaccines occur very soon after vaccinations, these include injection site pain, fever, chills and end after a few days. We cover these extensively in our articles Three Reasons Why Vaccines are Safe and 200 Million Doses Later, How Have the Vaccines Fared in the Real World.

Long answer:


The Oxford vaccine (as it’s commonly referred to) is an adenovirus based vaccine however it was earlier developed and tested for a variety of diseases including on Ebola (2014) and Zika (2016). Those trials weren’t successful at fighting disease but helped researchers test the safety of the vaccine. 

ChAdOx1 was then adapted to COVID19, early clinical trials had safety issues and moved to Phase I trials in early April. Phase II/III trials began in August in four countries: UK, Brazil and South Africa and final results were published in November. In total, ca. 23,000 participants were enrolled in the study. 

AstraZeneca is a 2 dose vaccine, given 28 days apart but now studies show that a 12 week break may increase vaccine effectiveness. The vaccine provides 76% protection after 1st dose, and 82% after 2nd dose (with a 12 week break). It’s shown to prevent deaths and hospitalisation by 100% and even may lower the chance of you infecting other people! Furthermore, it can be stored at normal fridge temperatures making handling it easier for those of us in the tropics. 

Against the UK variant, this vaccine shows 71.4% efficacy after two doses but against the more infectious South African variant, it’s down to 22% (albeit not a large and varied trial).


As mRNA technology is highly customisable, BioNtech developed 20 candidates for early stage research as soon as Chinese laboratories released the genetic sequences of Sars-Cov-2 in Jan 2020. 

As shown in the timeline below, they then teamed up with Pfizer and began Phase I and II trials simultaneously. The results were reviewed by the FDA, it then moved the best performer to Phase II / III trials  enrolling 44,000 people across US, Germany, Turkey, South Africa and Brazil. They then met the objective in November 2020 and conducted safety and efficacy assessments on over 38,000 people that took part in the trials. 

Pfizer/BioNTech is a 2 dose vaccine, given 28 days apart and is shown to reduce the chance of getting sick from COVID19 by 94% (i.e. vaccine efficacy is 94% after 2nd dose). It needs to be stored at -70C making it an expensive and difficult option for tropical countries such as Sri Lanka.


The Moderna vaccine, mRNA-1273, is also based on mRNA technology. The short list of vaccine candidates was ready to enter into the research process by January 16th, an amazing 2 days after the Chinese laboratory released the genetic sequence but long before the first cases were detected in the US. Phase I trials began in mid-March with Phase II & III running concurrently from end July with 30,000 participants in the US. 

Moderna is also a 2 dose vaccine, given 28 days apart, reducing the chance of developing COVID19 symptoms by 94%. It also requires cold storage but around -20C which makes it the better mRNA vaccine for Sri Lanka. 


This vaccine, NVX-CoV2373 is also 2 doses (beginning to sound familiar) 28 days apart however this is a protein subunit vaccine. That means it injects a lab made version of the outer shell (spike proteins) of the Sars-CoV-2 virus. This vaccine method is used in existing vaccines like the flu vaccines, HPV and Hepatitis B vaccines. Novavax Phase 3 trials spanned multiple countries and enrolled 30,000 people – none of whom had a serious reaction to the vaccine. 

Its UK trial showed that its 89.3% effective at preventing COVID19 symptoms and its South African trial showed a 60% reduced risk against the South African variant. The Novavax vaccine is another suitable candidate for Sri Lanka given its ability to be stored at 2 to 8C. 

Part 4: Do the vaccines alter my DNA?

Short answer: None of the vaccines alter your DNA. mRNA doesn’t hang around in your body for long and disintegrates after a certain short time period and as such are safer than traditional vaccines. The four main vaccines discussed here only allows your body to recreate the outer shell of the virus (a dummy version!) so your body can arm itself against it. When the real thing comes, the body is able to attack it faster now that it knows what the dummy looks like. 

Long answer: The aim of a vaccine is to teach the body how to recognise the virus. When a virus infects you, it enters into your cells and uses your cells to create more versions of itself. If your immune system can’t catch it early, all havoc breaks loose. Vaccines just give your immune system a blueprint of what to expect so it can prepare itself. 

  • None of the vaccines carries the entire viral structure. Much like our blueprint is our DNA, the virus blueprint is its DNA or RNA. We simply recreate an artificial part of this blueprint to help the body build the outer shell of the virus (or the spike proteins). Human equivalent would be to use your DNA to only recreate your skin. 

  • mRNA creates proteins, it doesn’t create DNA. When mRNA vaccines enter your cells, it releases the mRNA. The mRNA does not enter into the nucleus where your DNA is hosted. Helpers called ribosomes come alongside the mRNA strands and like construction workers laying brick after brick following an architect’s blueprint – starts to assemble the spike proteins or dummy outer shell of the virus. 

  • The spike proteins do not cause any harm on their own because they don’t have the ability to replicate. That ability lies within the virus’ RNA or DNA and we didn’t recreate that. The spike proteins are sent to the cell surface and held out (like waving a flag from a window) or released into the bloodstream. 

  • Vaccines help our immune system arm up against a potential intruder. Our immune system recognises Sars-Cov-2 via the spike protein. By sending some “placebo” spike proteins we give them an early chance to get prepared. Immune cells are usually patrolling around looking for potential intruders. When these sentries come across the spike proteins, they launch an immune response. 

  • All four vaccines activate both arms of our immune system: the innate and acquired arm. Once the immune system recognises the intruder, it will start to create antibodies to fight against it and more importantly, activate memory cells that will remember this knowledge for a time period. 

Want to know if the vaccines are safe? Read the next blog! 


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COVID. Quarantine. Isolation. Explained.

COVID. Quarantine. Isolation. Explained.


COVID, quarantine, isolation are words which we have heard for the last eight months, but do you know what exactly they mean and how they all differ? Let’s take a look. 

 A little background hurts no one

COVID-19 is an infectious disease caused by a group of viruses called coronavirus. Coronavirus means a crown, and it gets its name from its structure. The virus looks like it has a crown around it.

There are many different types of coronaviruses, and they infect a wide range of mammals and birds. Some even cause mild respiratory disease in people every year, so coronaviruses are not new. However, the virus that causes COVID-19 is new. 

SARS-CoV-2 causes COVID-19, and it originated from bats. The virus has been present in bats for a long time, but now the virus has evolved to be able to infect humans and be transmitted between humans. This is the 3rd type of coronavirus that has developed in the same manner. The earlier two coronaviruses caused Middle East Respiratory Syndrome (MERS) in 2012 and Severe Acute Respiratory Syndrome (SARS) in 2003.

Symptoms of COVID-19

Symptoms of COVID-19 include fever, cough, sore throat, tiredness, headache, loss of taste and smell and many others. The combination of symptoms and the severity of them varies from person to person and within regions. The most common symptom seen in patients with COVID-19 is cough, fever and loss of taste. However, most who have the virus may be asymptomatic, showing no symptoms at all and can still infect those around them.

If you are experiencing any of these symptoms call 1390 or use the COVID-19 self-assessment on the oDoc app to understand your symptoms and measures you need to take.  

How does COVID-19 get transmitted so rapidly from one person to the other? 

The virus in infected individuals lives in their respiratory tract, in their mouths, noses, and throats. 

There are two ways transmission of the virus can take place between individuals. 

  • When an infected person speaks, laughs, sneezes or coughs the virus can spread in forms of droplets. This droplet can be inhaled by non-infected people, thereby infecting them.
  • Likewise, the droplets can land and live on surfaces, and when a non-infected person touches these surfaces and then goes on to touch their nose, mouth or eyes, the virus can be transmitted into the non-infected person, thereby infecting them. 

Something to keep in mind is that SARS-CoV-2 is transmitted very easily. So this virus is transmitted between people in ways that make it very difficult to detect and prevent. People are infectious before they have symptoms, so they may be infecting others and not even know it. 


Keep reading!

The infection – a timeline

Let’s say, on day 1, a person gets infected, and enters the incubation period. 

Incubation period – the time between contracting the virus and starting to show symptoms. An infected person  cannot transmit the disease to others during this period. The incubation period for COVID-19 lasts from 2-14 days with an average of about five days, and then the infected person  enters the infectious period. 

The incubation period for this particular individual lasts 14 days, so they will start showing symptoms on day 14. Day 1 of symptoms  (day 14 of the incubation period in this case) is when they are most infectious. An important thing to note is, even though signs only show itself on day 14, the infectious period begins two days before symptoms show (day 12). 

Infectious period – when the infected person  can transmit the virus to others. The infectious period starts two days before the infected person starts showing symptoms. An infectious person  needs to be isolated, and anyone who comes into contact with them needs to be quarantined. 

The infectiousness of an individual gradually decreases with time. A person is said to be completely free of COVID-19 only when they don’t show any signs of fever for more than 24hrs, and symptoms get better.  In Sri Lanka, a patient is only declared as recovered if the PCR test comes out negative. 

Mild COVID-19 illness can last for about ten days, whereas severe conditions last for more than two weeks. 

Aren’t quarantine and isolation the same thing?

Contrary to popular belief, they are very different. 

When an individual is tested positive for COVID-19, they need to be isolated. This is practised to keep infected individuals away from the healthy population. Isolation period is usually up to 10 days or until signs, and symptoms get better or no sign fever for 24hrs. 

If an individual comes in contact with someone who has tested positive but hasn’t developed any symptoms themselves, they need to be quarantined. This helps prevent spread of disease that can occur before a person knows they are sick or if they are infected with the virus without feeling any symptoms. An individual needs to quarantine themselves for 14 days from the day they came in contact with the positively tested person. 

Suppose you live with a person who has tested positive and is isolating themselves in the same house/ shares communal space with you. In that case, you need to quarantine for the period they are isolating themselves and an additional 14 days from the last day they showed symptoms and signs of COVID-19. 

For example, if your family member tested positive on the 1st of November and recovered on the 14th of November, your quarantine will only end on the 28th of November (14 days from family members recovery). 

The future 

Until a vaccine or treatment for COVID-19 is found and distributed it is up to each one of us to follow safety protocols given by the government to keep ourselves and our local communities safe. Following the DREAM guidelines set out by the government is vital as we slowly resume into normalcy. Adjusting to the new normal may be difficult and frustrating but it is important that we avoid crowded places and gatherings in the near future. It is in our own hands to ensure the safety of ourselves and our loved ones. If you are experiencing any of these symptoms quarantine yourself and call 1390 immediately or use the COVID-19 self-assessment on the oDoc app to understand your symptoms and measures you need to take.


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Understanding Post Traumatic Stress Disorder

Understanding Post Traumatic Stress Disorder


Understanding Post Traumatic Stress Disorder

Our little island nation has experienced much trauma in our long history, this last year and a half being no exception. With the devastating Easter Sunday attacks last year and the current COVID-19 pandemic, many of us are dealing with the loss of loved ones and the stress of financial instability. As COVID-19 cases continue to rise, the government has imposed curfews or severe restrictions on movement. The aftereffects of these actions have challenged Sri Lankans, some of us harder than others. 

Historically, Sri Lanka has not placed enough emphasis on the role of the emotional impact of traumatic events such as these on a person’s psyche. Our system lacks sufficient psychological & psychiatric support for people who’ve lived through traumatic circumstances, be it through the stress of the pandemic, Easter Sunday attacks, the 30 year long civil war that devastated our nation or the abuse happening in our own homes. 

To that end, we’ve compiled a short primer on one of the most prevalent disorders that arise out of such events in the hope that it will prove of worth to help a loved one or your own self. 

What is PTSD? 

People who have lived through a traumatic event can find themselves experiencing emotional challenges long after the event has taken place. 

PTSD can develop after either a single isolated event or more recurring traumatic experiences. 

Not everyone who has undergone a traumatic event is likely to suffer from PTSD. Some may have strong feelings of sadness, stress, helplessness or fear but these symptoms can lessen over time as they continue to heal. However, a person who struggles with PTSD can experience symptoms that continue to cause them significant emotional disturbances and distress. 

Symptoms of PTSD

A person who maybe suffering from PTSD may have 4 main types of difficulties:

  1. Re-living the traumatic event – the person relives the event through recurring nightmares or memories and feels as though the event were happening again. They can have strong physical responses such as increased heart rate, sweating or panic. 
  2. Avoiding reminders of the event – The person actively avoids thoughts, feelings, conversations, even people and places that remind them of the traumatic event. 
  3. Being overly alert – The person may experience sleeping difficulties, irritability, lack of concentration, becoming easily startled and constantly on the lookout for danger. 
  4. Feeling emotionally numb – the person may feel distant from others, a loss of interest in day to day activities and experience difficulty in positive feelings such as happiness or love. 

If these symptoms persist for longer than a month and are not due to medication, substance use or other illness, it is likely that the person is suffering from PTSD.

Coping with PTSD

Many people suffering from PTSD turn to unhealthy coping strategies such as alcohol or drug abuse or deliberate self-harm. As such, it is important to seek out a qualified professional to speak with – this may help bring back hope through the sharing of experience and helping learn healthy & effective ways of coping. 

What can I do to help if I see a loved one suffering from PTSD? 

Finding ways to support a loved one with PTSD can be complicated but one of the most helpful things you can do yourself is learn about the symptoms and trials of living with PTSD. Familiarising yourself with what your friend or family member is going through can make it easier for them to have conversations. 

Actively listening to your loved one instead of trying to “fix” their problems is helpful. Just give them a safe space free of judgement and criticism. 

Encouraging your loved ones to seek help from a trained professional is of paramount importance. There are also many online support groups in Sri Lanka (links below) that can help your loved one connect with others who may be going through similar traumatic experiences. 

What does PTSD look like in children? 

Adults are not the only ones to suffer from PTSD and given the recent cases of child abuse in the news with perhaps countless cases happening behind closed doors, it is useful to understand how we can determine whether a child is suffering from PTSD. Symptoms vary depending on age as described below. 


  • Cry or scream a lot
  • Eat poorly due to loss of appetite
  • Experience nightmares of night terrors
  • Overwhelming fear of being separated from parent or caregiver

School age

  • Have a hard time concentrating at school
  • Experience insomnia or nightmares
  • Have feelings of guilt or shame
  • Very anxious or fearful in certain situations


  • Eat poorly
  • Self-harm
  • Feels depressed or alone 
  • Takes alcohol or drugs
  • Engage in risky sexual behavior
  • Make impulsive dangerous decisions

How can we help children suffering from PTSD? 

Try to keep your child’s schedules and lives as similar as possible to before the traumatic event. This might mean having your child continue with school and other activities with little time off in the beginning. 

Let them talk about the traumatic experience when and if they feel ready. Encouragement and praise helps them talk about their feelings but be careful not to force the issue if they don’t feel like sharing. If not through speaking, drawing and writing may help. 

Validate and reassure them that their feelings are normal. 

Seek out professional help immediately if you have any concern that a child has thoughts of self-harm. Thoughts of suicide are serious at any age and should be treated right away.

Build their self-confidence by encouraging them to make everyday decisions where appropriate. Children suffering with PTSD can feel powerless and helpless, so making decisions, however minor, can help them get control over some parts of their lives. 

Tell them that the traumatic incident is not their fault. They can talk about their feelings of guilt or shame but don’t let them blame themselves. 

Stay in touch with caregivers. It’s important to talk to teachers, babysitters, and other people who are involved in your child’s life.

Resources & References

Sri Lankan Resources

You can get in touch with medical professionals on the oDoc app who are trained to help people suffering from PTSD. You can even purchase an oMind subscription package which gives you unlimited access to mental health professionals.


Online Support Groups

PTSD Blogs

Mindfulness Apps


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How To Manage Stress

With the cost of living rising rapidly by the day, the currency devaluing, and the country falling into economic decline, it is no surprise that

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Breaking out of the cycle of anxiety

Breaking out of the cycle of anxiety


Sudden heaviness in the chest, an unsettled feeling you can’t place, your heart beating over time and you feel frozen in the moment. Hands start to clam up, your gut feels funny and breathing becomes short and shallow. 

For over 280 million people around the world suffering from an anxiety related disorder, this is often a reality. Triggered by a sound, a photograph, a smell, a memory – the options that revert our bodies back to the ancient fight or flight mode are endless.

What is anxiety?

Anxiety is defined by the American Psychological Association as “an emotion characterized by feelings of tension, worried thoughts and physical changes like increased blood pressure.” Normal feelings of anxiety are common given the complex situations we find ourselves in however it is important to identify the difference between regular anxiety and an anxiety disorder to seek the help we need.

Anxiety is an important emotion to keep us safe from harmful situations – since the ancient days, when our ancestors encountered a dangerous situation, e.g. a sabre-tooth tiger, an internal danger alarm has been triggered. The alarm releases a rush of the hormone adrenaline in the brain and adrenaline’s main task is to facilitate the “flight or fight response” against the impending threat. 

Noticeable signs of the flight or fight response is an elevated heartbeat, sweating and increased sensitivity to surroundings. Blood is diverted away from processes such as digestion towards the muscles of the limbs to allow the body to flee the situation if needed.

The limbic system

The limbic system is a group of brain structures (i.e. hippocampus, amygdala, hypothalamus) that work to elicit our behavioral and emotional responses, in particular those we’ve required for survival from ancient times (i.e. eating, sleeping, taking care of our young, staying alive).

When our eyes see danger, they send information to the amygdala which is responsible for emotional processing. The amygdala processes the information and if there is perceived danger, it sends a signal to the hypothalamus (or the command centre). The hypothalamus communicates with the rest of the body by releasing hormones that affect the autonomic nervous system. It can either push gas to the pedal via the sympathetic branch of the autonomic nervous system OR it can press the brakes via the parasympathetic branch. When sensing danger, its gas to the pedal via release of adrenaline (hormone) to trigger the flight or fight response to give the body enough energy to flee the danger. 

All this feels like: increased heart rate, more blood to muscles, heart and other vital organs, higher blood pressure, quicker breaths to allow more oxygen uptake, senses become sharper. And all this can happen in a second which is why before you’ve even truly clocked onto the car that’s coming at you, you’ve already jumped out of its way.

When does it become a problem?

So whilst the limbic system controlled flight or fight response may no longer be required to flee from predators, sustained exposure to modern day stressors like traffic jams, work pressure or family issues could cause the stress response to overfire and result in an anxiety disorder. 

As a result, some people become stuck in a cycle of stress which they are unable to break leading to chronic stress. Chronic stress or anxiety results in elevated levels of certain hormones that can harm the body in the long run. 

5 tips to break the cycle

As the limbic system reflex is so quick that we suddenly feel all the reactions in our bodies before we even know what’s happened, it’s important to rely on the basics to activate the parasympathetic nervous system (“PNS” or the brakes) which literally calms your body. The focus is on activating the vagus nerve (one of the main nerves of the body and part of the PNS) which has an effect on the breath, heart rate and digestive system and vice versa.

Here are five tips that are known to help calm the brain during episodes of anxiety:

1. Take deep breaths

Given the shallow breathing that’s associated with anxiety, taking the time to focus on taking deep breaths allows the body to stop the sympathetic nervous system in its tracks. This pause two fold benefits: 1) deep breathing stimulates the vagus nerve and 2) focussing on the breath allows the mind to hone in on a repetitive soothing pattern. 

Close your eyes if possible. Inhale for a count of 3, opening up your rib cage as the air flows in (like its a balloon), hold the breath for a count of 3 and slowly exhale through the nose for a count of 3.

Can be done anywhere you feel anxiety is being triggered: in the car, in the middle of a meeting or whilst shopping. 


2. Hum or sing to yourself (or to others!)

As the vagus nerve is connected to your larynx (or vocal chords) and the muscles of your throat, the gentle vibrations associated with humming activates these muscles and stimulates the nerve. Humming also forces you to control your breath and we know how much this helps!


3. Exercise

Physical activity is important for a myriad of reasons and helping you break the stress cycle is just one of the many. Exercise releases our happy hormones, or endorphins which counteract the effect of elevated adrenaline in the body. Physically moving the body allows for the dissipation of the built up tension in the muscles but also forces the body to breath deeply. 

4. Journal

Making your mind stop and take notice of the present helps it re-evaluate the threat level (and often realise, there’s nothing around to truly trigger this response). However, if there is something that is triggering the response, journaling also helps provide perspective to yourself. 

Take a note pad, a piece of paper or even your phone and write out everything you are feeling and thinking. Continue till you have written it all out. The act of writing takes our thoughts out of our mind and acts as a form of release. 

5. Speak to someone

Counsellors and psychologists are trained to help us decipher our thoughts, patterns and behaviours in a way that’s not possible alone. They provide perspective, ask questions and customise activities to help us break out of cycles that are causing us harm. 

With oDoc you can speak to a certified counsellor, psychologist or mental health professional from the safety and privacy of your own home via our app. 

2020 has been a year that has thrown most of our plans in the year, created numerous situations that could trigger anxiety and as such, what you feel is perfectly okay. You are, after all, human. Having to continue to suffer under the hand of an invisible threat is not the best way to live your life. Take hold of these ideas, speak to a professional and take control of your mind, body and your life! We are rooting for you!



The Limbic System, Queensland Brain Institute  

Understanding the Stress Response, Harvard Health Publishing

Calming Your Brain During Conflict, Harvard Business Review

This Might be the Simplest Scientific Way to Get Rid of Stress You’ve Ever Heard Of, Inc Publishing


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