The spread of the coronavirus is being increasingly driven by people aged in their 20s, 30s and 40s and many are not aware that they have been infected, the World Health Organisation's regional director for the Western Pacific said on Tuesday.
WHO officials said this month the proportion of younger people among those infected had risen globally, putting at risk vulnerable sectors of the population worldwide, including the elderly and sick people in densely populated areas with weak health services.
"The epidemic is changing," WHO Western Pacific regional director, Takeshi Kasai, told a virtual briefing.
"People in their 20s, 30s and 40s are increasingly driving the spread. Many are unaware they are infected."
"This increases the risk of spillovers to the more vulnerable: the elderly, the sick people in long-term care, people who live in densely populated areas and underserved areas," Takeshi Kasai told a virtual briefing.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
A surge in new cases has prompted some countries to re-impose curbs as companies race to find a vaccine for a virus that has battered economies, killed more than 770,000 people and infected nearly 22 million, according to a Reuters tally.
Surges were reported in countries that had appeared to have the virus under control, including Vietnam, which until recently went three months without domestic transmission due to its aggressive mitigation efforts.
"What we are observing is not simply a resurgence. We believe it's a signal that we have entered a new phase of pandemic in the Asia-Pacific," Kasai said.
He said countries were better able to reduce disruption to lives and economies by combining early detection and response to manage infections.
While mutations had been observed, the WHO still saw the virus as "relatively stable", Kasai said.
WHO also reminded drugmakers to follow all necessary research and development steps when creating a vaccine.
Socorro Escalante, its technical officer and medicines policy advisor, said the WHO was coordinating with Russia, which this month became the first country to grant regulatory approval for a COVID-19 vaccine.
"We hope to get the response in terms of the evidence of this new vaccine," Escalante said.Follow our full coverage of the coronavirus pandemic here.