PCR Testing is the most sensitive test that is currently available, able to detect active infection some days before the patient is infectious or symptomatic. It is recognised worldwide as the gold standard test. PCR testing is performed in machines that cycle through different temperatures. The analysis of the samples takes around 5 hours to perform, but as analysis sometimes have to be repeated, a turnaround time of 36 hours is often given.
LAMP Testing is another form of genetic test, able to detect the RNA of the virus. It is a more recent development than PCR and is performed all at one temperature. It is generally faster and cheaper than PCR but is not considered to be as sensitive – but is still more sensitive than antigen testing. LAMP tests might be able to detect patients immediately before symptoms are displayed but this is not verified at present. Rapid LAMP testing can add a significant degree of confidence if performed before flying, for example, when all aboard have had a LAMP test prior to departure.
Antigen Testing is the fastest and cheapest of all lab tests for COVID-19. Unlike PCR and LAMP, the genetic material of the virus is not searched for, but rather the protein structures on a virally infected cell produced by COVID-19; usually the so-called ‘spike’ protein. Antigen tests often become positive after having had symptoms for a couple of days. Their use is particularly powerful when patients are attending communal events and a quick check needs to be performed to see if attendees are infectious with COVID-19. Furthermore, during winter months, when people often have symptoms of the common cold or flu, performing an antigen test will ascertain whether the condition is the coronavirus or not.
Antibody testing is a blood test that identifies the presence of antibodies manufactured by the body in response to infection by COVID-19. A positive test for IgM antibodies indicates that the patient may have been infected and their immune system has started to respond to the virus or that the patient may have recently recovered from a COVID-19 infection. This type of test is required for most passengers entering China. Please check specific requirements with the Chinese Embassy.
Flights to mainland China require negative results from nucleic acid and IgM antibody tests conducted within 48 hours prior to departure. Passengers departing Singapore to China (effective from 17 Aug) who are vaccinated with mRNA vaccines (Pfizer-BioNTech/Comirnaty and Modena) will need to take the nucleic acid and N protein antibody tests within 48 hours prior to departure (IgM antibody test is not required).