As the world is seeing spikes in hospitalization and deaths caused by predominantly BA.4 and BA.5 Omicron subvariants in the past weeks, China's health officials said its latest COVID-19 control measures still provide the best protection to its people while minimizing the impact on its economy.

Dong Xiaoping, chief expert of virology at the Chinese Center for Disease Control and Prevention (CDC), said at a press conference on Thursday that there's no evidence showing ineffectiveness of non-pharmaceutical interventions against the increased transmissible BA.4 and BA.5 subvariants of Omicron. 

"In other words, the country's current prevention and control measures are still effective," Dong said.

China updated its guidelines for prevention and control of COVID-19 to the 9th version last month, which largely cut down quarantine days for international arrivals and streamlined testing and control measures for close-contacts of COVID-19 patients, a move that the officials claimed to be up-to-date in accordance with the characteristics of the virus.

After running under the new protocol for nearly a month, the country has seen multiple and repeated outbreaks with seven provinces reporting over hundreds of cases in the past week, according to He Qinghua, deputy director of the Disease Control and Prevention Bureau at the National Health Commission.

However, He said the local outbreaks are well controlled within a short period of time, which demonstrates the progress of the country's ability to contain the disease at provincial level. 

He attributed the recent rise to the increased internal travels during summer breaks and the surge at international levels.

'COVID-19 is nowhere near over' 

Globally, the number of new COVID-19 cases rose for the fifth week in a row, according to the World Health Organization (WHO) weekly report as of July 14. 

"New waves of the virus demonstrate again that COVID-19 is nowhere near over," said WHO Director-General Tedros Adhanom Ghebreyesus during a press briefing last week. 

"The virus is running freely and countries are not effectively managing the disease burden," he added.

Coronavirus will keep mutating

The contagiousness of a disease is measured by its basic reproduction number (R0), which calculates the average number of people an initial case infects in a population with no immunity (from vaccines or previous infection).

Some recent calculations have suggested that the R0 of BA.5 is 18.6, which would be nearly six times that of the original strain of the SARS-CoV-2 virus that emerged in 2019 and was estimated to have an R0 of about 3.0 to 3.3.

Although the result is questioned by other scientists, the trend does suggest the growing transmissibility of Omicron subvariants.

With BA.4 and BA.5 becoming the dominant strains, these more infectious subvariants appear to be masters at evading immunity, causing experts' concern for more mutations.

Dong said that the mutation of the coronavirus is an intrinsic characteristic, and Omicron will not be the last variant. 

New variants turn up when they have a chance to continue to infect people, but the most significant changes occur when someone is immunocompromised and chronically ill with COVID-19, which gives the virus more opportunity to change, according to virologist Stuart Turville from the Kirby Institute.

"China will continue to monitor and study the transmissibility, pathogenicity and immune evasion of the variants," Dong said.