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Why can you still get influenza if you’ve had a flu shot?

<p>Restrictions have eased, international borders are open and influenza is back in Australia after a two-year absence.</p> <p>Suddenly, major <a href="" target="_blank" rel="noopener">flu outbreaks</a> are occurring across the country, catching many off guard.</p> <p>Flu vaccinations aim to protect against four influenza viruses that cause disease in humans (two subtypes from influenza A and two from influenza B).</p> <p>But vaccine-mediated protection varies each year depending on how well the vaccine matches the disease-causing influenza viruses that are circulating at a given time. Vaccine effectiveness – a real-world measure based on the proportion of vaccinated people who still develop the flu – <a href="" target="_blank" rel="noopener">ranges</a> from <a href="" target="_blank" rel="noopener">16%</a> to <a href="" target="_blank" rel="noopener">60%</a>.</p> <p>However, it’s still important to get your flu shot. If you’ve been vaccinated and still get the flu, you’re <a href="" target="_blank" rel="noopener">less likely</a> to get as sick.</p> <h2>Why it’s difficult to predict which subtypes will dominate</h2> <p>Of the four types of influenza viruses that exist in nature, two cause significant disease in humans: influenza A and influenza B.</p> <p>The 2022 influenza vaccine is quadrivalent (targets four distinct viruses): two influenza A viruses (subtypes H3N2 and H1N1) and two influenza B viruses from distinct lineages.</p> <p>Within each flu A subtype further genetic variation can arise, with mutations (known as genetic drift) generating many viral variants that are classified into “clades” and sub-clades.</p> <p>H3N2 is particularly good at generating lots of diversity in this way. So predicting exactly which H3N2 virus to target in the vaccine is especially difficult.</p> <p>A key challenge for flu vaccines is the decision for which virus to target has to be made months ahead of time. The the H3N2 virus in the Australian flu vaccine (A/Darwin/9/2021) was chosen in September 2021 to enable the vaccine to be manufactured and distributed in time for the 2022 winter.</p> <p>There is no guarantee a different H3N2 virus that isn’t so well targeted by the vaccine won’t arrive in the country in the months leading into winter and start causing disease.</p> <p>Another factor that has made predicting which H3N2 virus to target in the vaccine uniquely difficult for 2022 is the lack of data on which viruses were dominant in the preceding flu seasons, both in Australia and on the other side of the Equator.</p> <p>With travel restrictions easing towards the end of 2021, flu cases did start to reappear during the northern hemisphere 2021-22 winter. But the lack of flu cases during the preceding seasons (due to COVID) meant the data used to predict which viruses to target was inadequate.</p> <p>The US Centers for Disease Control (CDC) analysed data from more than 3,000 children and <a href="" target="_blank" rel="noopener">found</a> a vaccine effectiveness of just 16% protection from mild to moderate disease from H3N2. Protection from more severe disease was just 14%.</p> <h2>We don’t know which subtypes will circulate in Australia</h2> <p>Data about flu vaccine effectiveness in the southern hemisphere 2022 winter isn’t yet available, and it’s unclear how protective the current vaccine is against the currently circulating disease-causing subtypes.</p> <p>While H3N2 viruses appears to be <a href="" target="_blank" rel="noopener">driving some disease now</a>, other flu viruses may become more prevalent later in the season.</p> <p>The flu vaccine is a quadrivalent vaccine, so in addition to influenza A H3N2, it will protect against another influenza A subtype (H1N1) and two distinct lineages of influenza B virus. These viruses don’t change as rapidly as H3N2, so it’s more likely the vaccine will give better protection against these other influenza viruses.</p> <p>Even if vaccine protection against H3N2 is lower than usual this year, the vaccine <a href="" target="_blank" rel="noopener">could make the difference</a> between recovering at home versus ending up in hospital.</p> <h2>So who should get a flu shot and when?</h2> <p>The flu vaccine offers the highest level of protection in the first three to four months months after vaccination. The season <a href="" target="_blank" rel="noopener">generally peaks</a> between June and September – although this year we have seen a much earlier than usual start to the flu season. It’s unclear whether this early start will mean a longer flu season or an early finish. So it’s not too late to get vaccinated.</p> <p>Flu vaccines <a href="" target="_blank" rel="noopener">are recommended</a> for everyone aged six months and over, but are particularly important for people who are more at risk of complications from influenza, including:</p> <ul> <li>Aboriginal and Torres Strait Islander people aged six months and over</li> <li>children aged six months to five years</li> <li>pregnant women</li> <li>people aged 65 years or over</li> <li>people aged six months or over who have medical conditions that mean they have a higher risk of getting serious disease.</li> </ul> <h2>What if you still get the flu?</h2> <p>If you develop flu symptoms, isolate and <a href="" target="_blank" rel="noopener">see your GP</a> for an influenza PCR test to determine whether you are indeed infected with influenza, particularly if you’re in the higher-risk groups.</p> <p>Specific antivirals for influenza <a href="" target="_blank" rel="noopener">can help</a>, if given early. To ensure rapid access to particularly vulnerable aged-care residents, aged-care facilities are being <a href="" target="_blank" rel="noopener">stocked</a> with the flu antiviral drug Tamiflu.</p> <p>In New South Wales, free <a href="" target="_blank" rel="noopener">drive-through clinics</a> now offer testing for influenza, respiratory syncytial virus (RSV) and SARS-CoV-2, the virus that causes COVID. Other states and territories may follow.</p> <p><em><strong><span id="docs-internal-guid-b2ed596f-7fff-517f-5af4-3572469f8c42">This article originally appeared on <a href="" target="_blank" rel="noopener">The Conversation</a>.</span></strong></em></p> <p><em>Image: Shutterstock</em></p>


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Can your mobile phone get a virus?

<p>With nearly <a href="" target="_blank" rel="noopener">84%</a> of the world’s population now owning a smartphone, and our dependence on them growing all the time, these devices have become an attractive avenue for scammers.</p> <p>Last year, cyber security company Kaspersky detected nearly <a href="" target="_blank" rel="noopener">3.5 million</a> malicious attacks on mobile phone users. The spam messages we get on our phones via text message or email will often contain links to viruses, which are a type of malicious software (malware).</p> <p>There’s a decent chance that at some point you’ve installed <a href="" target="_blank" rel="noopener">malware</a> that infected your phone and worked (without you noticing) in the background. According to a global report commissioned by private company Zimperium, more than <a href="" target="_blank" rel="noopener">one-fifth</a> of mobile devices have encountered malware. And four in ten mobiles worldwide are <a href="" target="_blank" rel="noopener">vulnerable</a> to cyber attacks.</p> <p>But how do you know if your phone has been targeted? And what can you do?</p> <p><strong>How does a phone get infected?</strong></p> <p>Like personal computers, phones can be compromised by malware.</p> <p>For example, the Hummingbad virus infected <a href="" target="_blank" rel="noopener">ten million</a> Android devices within a few months of its creation in 2016, and put as many as <a href="" target="_blank" rel="noopener">85 million</a> devices at risk.</p> <p>Typically, a phone virus works the same way as a computer virus: a malicious code infects your device, replicates itself and spreads to other devices by auto-messaging others in your contact list or auto-forwarding itself as an email.</p> <p>A virus can limit your phone’s functionality, send your personal information to hackers, send your contacts spam messages linking to malware, and even allow the virus’s operator to “spy” on you by capturing your screen and keyboard inputs, and tracking your geographical location.</p> <p>In Australia, Scamwatch received <a href="" target="_blank" rel="noopener">16,000 reports</a> of the Flubot virus over just eight weeks in 2021. This <a href="" target="_blank" rel="noopener">virus</a> sends text messages to Android and iPhone users with links to malware. Clicking on the links can lead to a malicious app being downloaded on your phone, giving scammers access to your personal information.</p> <p>Flubot scammers regularly change their <a href="" target="_blank" rel="noopener">target countries</a>. According to cyber security firm Bitdefender, FluBot operators targeted Australia, Germany, Poland, Spain, Austria and other European countries between December 1 2021 and January 2 of this year.</p> <p><strong>Is either Apple or Android more secure?</strong></p> <p>While Apple devices are generally considered more secure than Android, and <a href="" target="_blank" rel="noopener">less prone</a> to virus attacks, iPhone users who “jailbreak” or modify their phone open themselves up to security vulnerabilities.</p> <p>Similarly, Android users who install apps from outside the Google Play store increase their risk of installing malware. It’s recommended all phone users stay on guard, as both Apple and Android are <a href="" target="_blank" rel="noopener">vulnerable</a> to security risks.</p> <p>That said, phones are generally better protected against viruses than personal computers. This is because software is usually installed through authorised app stores that vet each app (although some malicious apps can occasionally slip through <a href="" target="_blank" rel="noopener">the cracks</a>).</p> <p>Also, in comparison to computers, phones are more secure as the apps are usually “<a href="" target="_blank" rel="noopener">sandboxed</a>” in their own isolated environment – unable to access or interfere with other apps. This reduces the risk of infection or cross contamination from malware. However, no device is entirely immune.</p> <figure class="align-center zoomable"><a href=";q=45&amp;auto=format&amp;w=1000&amp;fit=clip"><img src=";q=45&amp;auto=format&amp;w=754&amp;fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset=";q=45&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=1 600w,;q=30&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=2 1200w,;q=15&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=3 1800w,;q=45&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=1 754w,;q=30&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=2 1508w,;q=15&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=3 2262w" alt="A smartphone with a virus alert warning is held up by a hand in front of a dark background." /></a><figcaption><em><span class="caption">Apple devices are generally considered more secure against malware than Android devices, but they’re still at risk.</span> <span class="attribution"><span class="source">Pixabay/ (edited)</span>, <a class="license" href="" target="_blank" rel="noopener">CC BY</a></span></em></figcaption></figure> <p><strong>Watch out for the signs</strong></p> <p>While it’s not always easy to tell whether your phone is infected, it will exhibit some abnormal behaviours if it is. Some signs to watch out for include:</p> <ul> <li> <p>poor performance, such as apps taking longer than usual to open, or crashing randomly</p> </li> <li> <p>excessive battery drain (due to the malware constantly working in the background)</p> </li> <li> <p>increased mobile data consumption</p> </li> <li> <p>unexplained billing charges (which may include increased data usage charges as a result of the malware chewing up your data)</p> </li> <li> <p>unusual pop-ups, and</p> </li> <li> <p>the device overheating unexpectedly.</p> </li> </ul> <p>If you do suspect a virus has infected your device, there are some steps you can take. First, to prevent further damage you’ll need to remove the malware. Here are some simple troubleshooting steps:</p> <ol> <li> <p>Use a reliable antivirus app to scan your phone for infections. Some reputable vendors offering paid and free protection services include <a href="" target="_blank" rel="noopener">Avast</a>, <a href="" target="_blank" rel="noopener">AVG</a>, <a href="" target="_blank" rel="noopener">Bitdefender</a>, <a href="" target="_blank" rel="noopener">McAfee</a> or <a href="" target="_blank" rel="noopener">Norton</a>.</p> </li> <li> <p>Clear your phone’s storage and cache (in Android devices), or browsing history and website data (in Apple devices).</p> </li> <li> <p>Restart your iPhone, or restart your Android phone to <a href="" target="_blank" rel="noopener">go into safe mode</a> – which is a feature on Android that prevents third-party apps from operating for as long as it’s enabled.</p> </li> <li> <p>Delete any suspicious or unfamiliar apps from your downloaded apps list and, if you’re an Android user, turn safe mode off once the apps are deleted.</p> </li> </ol> <p>As a last resort, you can back up all your data and perform a factory reset on your phone. Resetting a phone to its original settings will eliminate any malware.</p> <p><strong>Protecting your phone from infection</strong></p> <p>Now you’ve fixed your phone, it’s important to safeguard it against future viruses and other security risks. The mobile security apps mentioned above will help with this. But you can also:</p> <ul> <li> <p>avoid clicking unusual pop-ups, or links in unusual text messages, social media posts or emails</p> </li> <li> <p>only install apps from authorised app stores, such as Google Play or Apple’s App Store</p> </li> <li> <p>avoid jailbreaking or modifying your phone</p> </li> <li> <p>check app permissions before installing, so you’re aware of what the app will access (rather than blindly trusting it)</p> </li> <li> <p>back up your data regularly, and</p> </li> <li> <p>keep your phone software updated to the latest version (which will have the latest security patches).</p> </li> </ul> <p>Continually monitor your phone for suspicious activity and trust your gut instincts. If something sounds too good to be true, it probably is.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="" alt="The Conversation" width="1" height="1" /></p> <figure><iframe src=";start=38" width="440" height="260" frameborder="0" allowfullscreen="allowfullscreen"></iframe><figcaption><em>Google’s tips on how to spot malware.</em></figcaption></figure> <p><em><a href="" target="_blank" rel="noopener">Ritesh Chugh</a>, Associate Professor - Information and Communications Technology, <a href="" target="_blank" rel="noopener">CQUniversity Australia</a></em></p> <p><em>This article is republished from <a href="" target="_blank" rel="noopener">The Conversation</a> under a Creative Commons license. Read the <a href="" target="_blank" rel="noopener">original article</a>.</em></p> <p><em>Image: Getty Images</em></p>


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How does the Wuhan coronavirus cause serious illness?

<p>We usually think of viral respiratory infections, like the common cold, as mild nuisances that pass in a few days. But the Wuhan coronavirus has proven to be different. Of those infected, <a href="">around 2%</a> are reported to have died but the true mortality is unknown.</p> <p>There’s much we’re yet to learn about this new virus, but we know it often causes <a href="">pneumonia</a>, an infection of the lungs which produces pus and fluid and reduces the lungs’ ability to absorb oxygen.</p> <p>Of the first <a href="">99 people with severe infection</a>, three-quarters had pneumonia involving both lungs. Around 14% appeared to have lung damage caused by the immune system, while 11% suffered from multi-organ system failure, or sepsis.</p> <p>Others are at risk of complications from being treated in hospitals, such as acquiring other infections.</p> <p>At this stage, we know some people develop only a mild infection, while others become critically ill, but the exact proportion of each is not yet clear.</p> <p>Overall, there are four key ways the Wuhan coronavirus can cause severe disease – and some can occur at the same time.</p> <p><strong>1. Direct viral damage</strong></p> <p>For the SARS (severe acute respiratory syndrome) coronavirus, <a href="">direct viral damage</a> was probably the most common way the infection caused disease. This is likely the case with the Wuhan coronavirus.</p> <p>Early <a href="">studies</a> have found the Wuhan coronavirus attaches to a particular receptor found in lung tissue. This is like a lock and key mechanism allowing the virus to enter the cell, and is the same receptor the SARS coronavirus used.</p> <p>Viruses “hijack” the host cell’s mechanisms to make more copies of itself. Damage results from either viruses taking over the cell completely and causing it to die, or immune cells recognising the viral infection and mounting a defence, triggering cell death.</p> <p>If large numbers of cells die, then the affected organ can’t function effectively.</p> <p><a href="">Studies</a> from patients who died from SARS coronavirus showed the virus caused damage to not only the lungs, but also other organs in the body. <a href="">Early research</a> suggests the Wuhan coronavirus can also damage other organs, including the kidneys.</p> <p><strong>2. Pneumonia</strong></p> <p>While we’re still piecing together the relationship between the Wuhan coronavirus and pneumonia, there’s much we can learn from influenza.</p> <p>Influenza is a virus but it commonly <a href="">leads to bacterial pneumonia</a> – this is what’s known as a secondary infection.</p> <p>It’s thought the influenza virus weakens the usual protective mechanisms of the lung, allowing bacteria to establish and multiply. This is especially true in children, older people and those with compromised immune systems.</p> <p>Secondary bacterial pneumonia is <a href="">more severe</a> than influenza alone – in hospitalised patients, around 10% of those with influenza and pneumonia die, compared to around 2% of those who don’t have pneumonia.</p> <p>The Wuhan coronavirus appears to cause pneumonia in two ways: when the virus takes hold in the lungs, and through secondary bacterial infections, however, the first way appears to be more common.</p> <p><strong>3. Sepsis</strong></p> <p><a href="">Sepsis</a> is a serious condition that can be caused by many infections.</p> <p>When we get an infection, we need to mount an immune response to fight off the pathogen. But an excessive immune response can cause damage and organ failure. This is what happens in the case of sepsis.</p> <p>Although it can be difficult to determine whether organ damage from the Wuhan coronavirus is a result of direct viral infection or indirect “collateral damage” from the immune system, <a href="">initial reports suggested</a> around 11% of people severely ill with the Wuhan coronavirus experienced sepsis with multi-organ failure.</p> <p>So far no drugs or interventions have <a href="">been able to dampen this immune response</a>. Although several treatments have been proposed for Wuhan coronavirus, none have yet been shown to work.</p> <p><strong>4. Complications of hospital care</strong></p> <p>Finally, patients who require hospital care may have complications. These include infections from intravenous lines (for drips/medication) or urinary catheters (flexible tubes inserted into the bladder to empty it of urine), pneumonia, or non-infectious complications such as falls or pressure sores.</p> <p><a href="">Studies</a> have found 10% of patients in hospital have some sort of health care-acquired infection, and around 5% have a pressure sore.</p> <p>Hospitals work hard to try to prevent these complications, by making sure health care workers disinfect their hands and other equipment. However, complications still occur, particularly in patients who are debilitated from long hospital stays.</p> <p>While most respiratory viral infections are mild, some can trigger serious complications, either directly or indirectly. It’s too early to tell how often this occurs with the Wuhan coronavirus. While we have initial data on those who were severely affected, many others may not have required medical care.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: --></p> <p><em><a href="">Allen Cheng</a>, Professor in Infectious Diseases Epidemiology, <a href="">Monash University</a></em></p> <p><em>This article is republished from <a href="">The Conversation</a> under a Creative Commons license. Read the <a href="">original article</a>.</em></p>

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