Several COVID-19 vaccines have already been approved by health authorities
common is that they all are zoonotic , meaning that they come from other animals ,” he said .
While population growth is putting pressure on land , climate change is adding massively to the risk of new diseases emerging and proliferating as a result of greater personal mobility that allows viruses to cross the world in a day .
Dr Piot believes that global warming is enabling mosquitoes to thrive in many more places than before , turning them into vectors for new diseases . Extreme weather events are also leading to more floods and an increase in waterborne infections , while deforestation means that humans are invading the habitats of animals carrying viruses .
“ We need to take good care of the health of other animals and of the planet . What all these diseases have in common is that they are zoonoses that originate in animals . It happens all the time that viruses are transmitted from animals to humans where in most cases nothing bad happens ,” Dr Piot said . “ Once a virus adapts and then can spread to others , that ’ s when we run into problems . Like HIV originated in chimpanzees , bats are notorious as a reservoir for corona viruses or Ebola . Then for influenza , we have a whole range of animals that can be the source , particularly all types of birds and also pigs ,” he explained .
Although it ’ s still not known what percentage of the population needs to be vaccinated in order to help protect the whole of society from COVID-19 through herd immunity , the figure is likely to be around 70 percent .
This means that 60-80 percent of the population needs to be vaccinated to protect everybody . To put this into perspective , for measles , there needs to be a minimum of 93 percent vaccination to avoid a pandemic . For pneumococcal pneumonia , the figure can be 50 percent .
“ It ’ s very important that we vaccinate to these percentages of the population to protect everybody and go back to normal . That ’ s why dealing with vaccine hesitancy is important , because if we drop from a coverage of 70 percent to 60 percent , then we ’ re all in trouble . It ’ s not just for individuals , but vaccines are there for societal hope ,” said Dr Piot .
One issue that could limit the chances of global herd immunity is lack of access to the various approved vaccines by all those who need it , not just citizens of wealthy countries with developed healthcare systems .
GlobalHealthAsiaPacific . com APRIL 2021
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