Vaccination, hospitalizations… Five years later, covid has changed era

More than five years after its appearance in China, the virus causing covid-19 has officially reached 777 million people and caused more than seven million deaths – many more in reality -, according to the World Health Organization. health (WHO).

But, over time and waves, the impact of respiratory infection on deaths and hospitalizations has greatly diminished, thanks to the immunity acquired by populations via vaccination and/or infections.

Covid is still killing (more than 3,000 deaths from October to November 2024 in 27 countries, according to the WHO). But the overwhelming majority of deaths were recorded between 2020 and 2022. Since spring 2023 and the lifting, by the WHO, of the maximum alert level, the pandemic is over.

The virus does not have a specific season but seems to be gradually becoming endemic, with regular resurgences, a bit like the flu, observe various experts.

People want to send covid into the past

But “the world wants to forget this pathogen that is still with us, people want to put covid in the past – and in many ways, act as if nothing had happened – because it has been so traumatic”, observes the Dr Maria Van Kerkhove, head of epidemic and pandemic preparedness at WHO.

Since fall 2021, the Omicron era has continued: one sub-variant replaces another, without being more severe. However, we should not entirely “discard the scenario of new variants that are more virulent or evade immunity”, say some scientists. In any case, Sars-CoV-2 will remain among humans.

• 2 Vaccines, treatments

  Crucial against the pandemic, vaccination has been massive since the extraordinarily rapid development of serums. More than 13.6 billion doses have been administered worldwide, with very unequal access between poor and rich countries.

  Vaccines adapted against Omicron – in its JN.1 version – currently remain recommended, particularly for the most vulnerable, because they still protect against serious forms and the risk of long-term covid. But vaccination coverage is insufficient, particularly among seniors and caregivers, warns the WHO.

  The quest for vaccines that act longer and more powerfully against infection and transmission continues, as does the quest for new methods of administration (nasal, oral, cutaneous).

  In terms of treatments, the pharmacy has been reduced since Omicron: a few direct antivirals and a monoclonal antibody.

  But certain innovations brought about or accelerated by the pandemic, particularly messenger RNA vaccines, remain a source of hope for other pathologies, such as cancer.

• 3 Covid long

  Fatigue, cough, shortness of breath, intermittent fever, loss of taste or smell, difficulty concentrating, depression… Long covid manifests itself by one or more symptoms, generally within three months after infection, persisting for at least two months and cannot be explained by any other diagnosis. “Approximately 6% of people infected with covid experience this complex syndrome,” the WHO said at the end of December, noting that this remains “a significant burden for health systems”. Women and people with previous health problems are more affected. And reinfections seem to increase the risks.

  Scientists have made progress, but have not fully elucidated its mechanisms, following several avenues: persistence of Sars-CoV-2 in the body, maintenance of an inflammatory state post-infection, formation of microclots, etc.

• 4 Future pandemics

  Covid-19 is not the last pandemic, scientists are certain. The question is when the next one will come, and whether the world will be better prepared.

  Around 60% to 70% of emerging diseases are zoonoses, arising from pathogens transmitted from vertebrate animals to humans – they are multiplying due to deforestation, which increases contact with wildlife, a reservoir of unknown viruses.

  Avian flu is currently under scrutiny, especially since a first human death in the United States. This was an elderly patient who suffered from other pathologies and who had been infected via farmyard and wild birds.

  For more than two years, WHO member countries, which are negotiating an agreement to prevent pandemics, have been slipping. The memory of the damage caused by covid is fading, governments are changing, and a blockage persists between rich and poor countries.