The World Health Organization (WHO) warned that there are no evidence proving that people who have recovered from the 2019 Coronavirus Disease (COVID-19) and have antibodies will not contract the illness again.
The WHO stressed that the organization continues to review antibody responses to Severe Acute Respiratory Syndrome Coronavirus-2, the virus that causes COVID-19), infections.
“Most of these studies show that people who have recovered from infection have antibodies to the virus. However, some of these people have very low levels of neutralizing antibodies in their blood, suggesting that cellular immunity may also be critical for recovery,” the WHO said in their website.
“As of 24 April 2020, no study has evaluated whether the presence of antibodies to SARS-CoV-2 confers immunity to subsequent infection by this virus in humans,” the organization added.
The Department of Health (DOH) in the Philippines has also confirmed that two discharged COVID-19 patients at the Southern Philippines Medical Center (SMPC) in Davao City have once again tested positive for the virus.
DOH Usec. Maria Rosario Vergeire said on Sunday, April 26, that the patients showed mild symptoms of the illness and the results of their Polymerase chain reaction tests proved that they contacted the disease.
Vergeire admitted that the patients got discharged after testing negative for the virus. However, they got re-admitted to SMPC due to testing positive again for COVID-19 after completing two weeks of home quarantine.
“Ang unang pasyente ay na-discharge na ulet dahil negatibo na ulet ang kanyang resulta, habang ang pangalawang pasyente ay naghihintay pa ng resulta ng kanyang swab (test). Mabuti ang kalagayan ng parehong pasyente,“ the DOH official said.
“Patuloy ang pag-aaral ng DOH at ng ating mga eksperto tungkol sa posibilidad ng re-infection or re-activation ng COVID-19. Wala pang sapat na ebidensya upang magbigay ng pahayag dito sa ngayon,” she added.
Vergeire, however, raised the possibility that the PCR tests detected remnants of the dead virus, which can no longer infect other people.
Australia’s Department of Health also mentioned that PCR tests cannot distinguish between ‘live’ virus and non-infective RNA (ribonucleic acid), the genetic material of a virus.
Aside from the Philippines, South Korea announced on April 12 that 111 recovered COVID-19 patients have tested positive for the illness again.
Reports also stated that around 14 percent of COVID-19 patients in China have tested positive for the disease for the second time after being cleared and discharged from the hospital.