Over 200,000 Hongkongers who have overcome their Covid infections have registered for "recovery QR codes," which are equivalent to a vaccine pass, to enter places of business such as restaurants, malls and supermarkets, just a day after the system was thrown open for registrations on Tuesday.

However, the Centre for Health Protection has also received more than 100,000 email enquiries about infection records.

Some of them centered around their inability to download codes despite having recovered from infections that they had declared to authorities.

One said she tested positive in rapid tests early last month and reported her infection through the Department of Health's self-declaration system, but her case fell through the cracks with the "recovery code" generation website indicating it did not have her record.

The center's principal medical and health officer, Albert Au Ka-wing, said his team is still updating the database amid a fifth wave that has seen over 1.18 million cases.

"There could be two major reasons for not getting the code, the first being the cases are not in our system yet and the second that they have yet to report positive rapid test result."

He advised people who encountered problems in getting the code to call the hotline 2569-5777 - which runs between 9am and 9pm. The center, Au said, is mulling over adding manpower to the call center.

People who recently contracted Covid infections, he said, have already received recovery codes in quarantine orders issued by the department, which will also be valid for 180 days.

Test contractor Prenetics said human errors in inputting data of 482 people - including 25 who tested positive - who did not receive phone messages on test results.

Those affected were among 1,002 people who submitted deep throat saliva samples to the Hospital Authority's outpatient clinics from February 21 to March 1.

Prenetics said it had apologized to those affected.

The 200,000 mark was reached at 5pm yesterday since the system went online Tuesday but doesn't include those who went for eHealth app codes.

Deputy government chief information officer Tony Wong Chi-kwong said most users completed registration in one to two minutes.

On the issue of the system failing to show recovery records in some instances, he said it could be the result of wrong information such as one's Hong Kong ID card number, date of infection, or even that they had never reported their infection to health authorities before.

This came as businesses, including restaurants, got the green light to forge ahead with a special sound alert system upon repeated scans of vaccine pass codes within a short period.

QR code race as glitches bug those beating Covid