The updated version of the guidelines explained that when five or more cases that are linked by the same location of exposure are confirmed, it is regarded as an infection cluster
China’s National Health Commission has released updated COVID-19 prevention and control guidelines by revising etiological and epidemiological features and epidemic monitoring.
The revised guidelines highlight that respiratory droplets remain the main route of COVID-19 transmission, but there is still a risk of infection through contaminated objects or to people exposed to environments under certain conditions.
The updated version of the guidelines explained that when five or more cases that are linked by the same location of exposure are confirmed, it is regarded as an infection cluster. In its previous versions, however, it identified the occurrence of two or more such confirmed cases as an infection cluster.
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.
For epidemiological investigations, the latest version has revised the definition of imported cases. It will now include, new infections linked to imported cases, and close contacts of close contacts, among other terms.
With that it has also revised the requirements for centralised isolation and home medical observation.
The revised guidelines state that after taking a COVID-19 test at ports of entry, passengers entering the mainland will be required to spend seven days in isolation centres for medical observation and take another test before completing quarantine.If the COVID-19 test result is negative, passengers from outside the mainland can isolate themselves at home for another seven days before they are free to travel around, the guidelines added.