TechCentralTechCentral
    Facebook Twitter YouTube LinkedIn
    Facebook Twitter LinkedIn YouTube
    TechCentralTechCentral
    NEWSLETTER
    • News

      Google’s giant Equiano Internet cable has landed in South Africa

      8 August 2022

      The African tech start-ups eyeing global markets

      8 August 2022

      Karpowership loses bid to overturn environmental ruling

      8 August 2022

      New app launched to tackle potholes in South Africa

      8 August 2022

      Rogue database felled Capitec in its worst-ever IT outage

      7 August 2022
    • World

      Nvidia issues profit warning on slump in demand for graphics cards

      8 August 2022

      Buterin: Mining on Ethereum Classic won’t affect Merge

      8 August 2022

      Musk challenges Twitter CEO to a public debate

      7 August 2022

      Amazon splashes $1.7-billion on Roomba maker iRobot

      5 August 2022

      Nigeria asks Google to block banned groups from YouTube

      5 August 2022
    • In-depth

      The length of Earth’s days has been increasing – and no one knows why

      7 August 2022

      As Facebook fades, the Mad Men of advertising stage a comeback

      2 August 2022

      Crypto breaks the rules. That’s the point

      27 July 2022

      E-mail scams are getting chillingly personal

      17 July 2022

      Webb telescope’s stunning images of the cosmos

      12 July 2022
    • Podcasts

      How South Africa can woo more women into tech

      4 August 2022

      Book and check-in via WhatsApp? FlySafair is on it

      28 July 2022

      Interview: Why Dell’s next-gen PowerEdge servers change the game

      28 July 2022

      Demystifying the complexity of AI – fact vs fiction

      6 July 2022

      How your organisation can triage its information security risk

      22 June 2022
    • Opinion

      SIU seeks to set aside R215-million IT tender

      19 July 2022

      No reason South Africa should have a shortage of electricity: Ramaphosa

      11 July 2022

      Ntshavheni’s bias against the private sector

      8 July 2022

      South Africa can no longer rely on Eskom alone

      4 July 2022

      Has South Africa’s advertising industry lost its way?

      21 June 2022
    • Company Hubs
      • 1-grid
      • Altron Document Solutions
      • Amplitude
      • Atvance Intellect
      • Axiz
      • BOATech
      • CallMiner
      • Digital Generation
      • E4
      • ESET
      • Euphoria Telecom
      • IBM
      • Kyocera Document Solutions
      • Microsoft
      • Nutanix
      • One Trust
      • Pinnacle
      • Skybox Security
      • SkyWire
      • Tarsus on Demand
      • Videri Digital
      • Zendesk
    • Sections
      • Banking
      • Broadcasting and Media
      • Cloud computing
      • Consumer electronics
      • Cryptocurrencies
      • Education and skills
      • Energy
      • Fintech
      • Information security
      • Internet and connectivity
      • Internet of Things
      • Investment
      • IT services
      • Motoring and transport
      • Public sector
      • Science
      • Social media
      • Talent and leadership
      • Telecoms
    • Advertise
    TechCentralTechCentral
    Home»In-depth»Why even with vaccines, Covid will always be with us

    Why even with vaccines, Covid will always be with us

    In-depth By Agency Staff22 June 2021
    Facebook Twitter LinkedIn WhatsApp Telegram Email

    The road to ending the Covid-19 health crisis is long and paved with uncertainty. Many countries are counting on vaccines to build sufficient immunity in their populations so that Sars-CoV-2 isn’t able to find susceptible people to infect, causing transmission of the coronavirus to slow and eventually stop. But even with the roll-out of highly effective vaccines, immunisation coverage may not reach that level — the so-called herd immunity threshold — anytime soon. Researchers warn that the virus is apt to be circulating among us forever, although it’s likely to become a less potent foe.

    1. Can Covid be eradicated?

    No. So far, only one human disease — smallpox — has been officially eradicated; that is, reduced to zero cases and kept there long term without continual countermeasures. That was thanks to a highly effective vaccine plus the fact that humans are the only mammals naturally susceptible to infection with the smallpox virus. It’s not feasible to banish Sars-CoV-2 from every species susceptible to it, including horseshoe bats, minks, cats and gorillas. The next best thing would be what’s known as disease elimination. That’s when there are zero new cases of an infection or disease in a defined area over a sustained period, such as 28 days. Some countries, such as New Zealand, have achieved zero new cases for lengthy periods using lockdowns, diligent case detection and isolation, and border closures. But keeping this up over the long run is challenging as citizens hunger for a return to normal life.

    2. Will vaccines eliminate Covid-19?

    There’s considerable uncertainty about that. Authors of a scientific paper published in November in the Lancet calculated that if a vaccine could provide a lifelong, fail-safe shield against infection with Sars-CoV-2, it would need to reach 60% to 72% of people to establish herd immunity. While the Covid vaccines in use around the world are good, they aren’t perfect, which means immunisation rates will need to be higher. The shots have been shown to offer 50% to 97% protection against becoming sick, but it’s mostly unknown how well they prevent people from getting an asymptomatic infection that could be passed on. If a vaccine is 80% effective at preventing any infection, 75% to 90% of people would need to be immunised, according to the Lancet paper. That would be a high bar given that large numbers of people are hesitant to get the vaccines and most of the shots are authorised only for adults and older children. Another unknown is the duration of protection. The shorter it is, the higher the rates of immunisation required to establish herd immunity. Vaccines might not have to do all the work to get there: Some people who’ve already had the virus will be protected against it, although not as well as those who’ve been inoculated.

    3. How do variants of the virus factor in?

    The more the coronavirus circulates, the more opportunity it has to mutate in ways that enhance its ability to evade the immunity people have gained from natural infection and vaccination. This year, more infectious variants that were first reported in the UK, South Africa, Brazil and India — where Covid epidemics have been particularly severe — have proliferated and spread internationally. Scientists say the vaccines should still work at stopping severe disease in the vast majority of cases, but some shots may be less effective at protecting against mild infections caused by a variant. Inoculations may need to be updated periodically to maintain their efficacy, and several vaccine makers have begun testing new versions and booster shots.

    Image: Daniel Schludi

    4. Do Covid vaccines have to prevent infection to curb cases?

    No. Vaccines don’t have to be perfect to have a public health benefit. New Zealand vaccinologist Helen Petousis-Harris points to rotavirus and chickenpox as examples of diseases that have been “virtually eliminated using vaccines that are very good at preventing severe disease, quite good at preventing any disease, but that do not completely prevent infection in everyone”. Since Sars-CoV-2 spreads through respiratory particles from an infected person’s throat and nose, a vaccine that reduces the amount of virus in the respiratory tract or how often an infected person coughs may decrease the likelihood of it being transmitted to others and lower the effective reproduction number (Re), which is the average number of new infections estimated to stem from a single case. Mike Ryan, head of the World Health Organisation’s emergencies programme, told reporters on 25 January that rather than focusing on eliminating Sars-CoV-2, success should be seen as “reducing the capacity of this virus to kill, to put people in hospital, to destroy our economic and social lives”.

    5. What if Covid isn’t eliminated?

    In a poll of more than 100 scientists conducted by the journal Nature in January, nearly 90% said they expected Sars-CoV-2 to become endemic. Viruses that are endemic continuously circulate in the community, often causing periodic spikes when conditions favour transmission. Examples include norovirus, the notorious cause of gastroenteritis on cruise ships, and the myriad viruses, including four coronaviruses, that cause the common cold, especially over the winter.

    6. What might the implications be?

    People who have survived Covid and those vaccinated against it will probably be shielded against the disease for some time. It’s likely that re-exposure to the virus will bolster their protection. In the absence of herd immunity, the virus will continue to find those who don’t have protection. That will mean people who don’t get vaccinated, or can’t — because their immune systems are compromised, or they have allergies to vaccine ingredients, or are too young — will remain vulnerable. Some scientists have predicted that, once the endemic phase is reached, then primary exposure to the virus will occur in childhood, when the infection mostly causes mild or no disease. At that point, Covid may be regarded much like the common cold.  — Reported by Jason Gale, (c) 2021 Bloomberg LP

    top WHO
    Share. Facebook Twitter LinkedIn WhatsApp Telegram Email
    Previous ArticleEchoes of neurodegenerative disease in fatal Covid cases
    Next Article ‘Make or break time for crypto’ as bitcoin price tumbles

    Related Posts

    The length of Earth’s days has been increasing – and no one knows why

    7 August 2022

    As Facebook fades, the Mad Men of advertising stage a comeback

    2 August 2022

    Crypto breaks the rules. That’s the point

    27 July 2022
    Add A Comment

    Comments are closed.

    Promoted

    You don’t need a call centre to take advantage of call centre technology

    5 August 2022

    Black man, you are still on your own

    5 August 2022

    UC&C interoperability offers businesses operational cost relief in tough times

    4 August 2022
    Opinion

    SIU seeks to set aside R215-million IT tender

    19 July 2022

    No reason South Africa should have a shortage of electricity: Ramaphosa

    11 July 2022

    Ntshavheni’s bias against the private sector

    8 July 2022

    Subscribe to Updates

    Get the best South African technology news and analysis delivered to your e-mail inbox every morning.

    © 2009 - 2022 NewsCentral Media

    Type above and press Enter to search. Press Esc to cancel.