AstraZeneca’s preventive COVID-19 therapy administered in Hainan, hospitals ‘considers double dosage against BA.4 and 5 subvariants’

Evusheld, AstraZeneca’s preventive COVID-19 therapy, had been used on two healthy subjects on July 9 in a hospital in South China’s Hainan Province. The drug, sold at 13,300 yuan ($1,985) for two injections, reportedly could provide protection for at least six months. However, considering the potential for an epidemic caused by the BA.4 and 5 subvariants, it requires a higher dosage of neutralizing antibodies to provide protection, media reported on Sunday citing experts.

The first administration of the therapy was conducted in the Boao Super Hospital in Hainan’s Boao Lecheng International Medical Tourism Pilot Zone, according to Chinese online news outlet Yicai.

Evusheld is a neutralizing antibody cocktail used in people with low immunity that should be effective for six months, though vaccination is still recommended as the best defense against the novel coronavirus. It was approved for sale in the US late last year and in Europe this March, according to media reports.

Although it has not been authorized in China nationally, the therapy was recently given green light to be imported and used in the Ruijin Hainan Hospital and Boao Super Hospital in Hainan’s Boao Lecheng International Medical Tourism Pilot Zone.

The hospitals will each administer Evusheld to more than 10 patients starting July 9, Yicai reported. The treatment is not covered by China’s medical insurance program.

Currently, it is mostly students who are preparing to go overseas who come to the Boao Super Hospital and register for injections, according to Yicai.

AstraZeneca still needs to conduct clinical trials specifically on the Chinese population to gain authorization and officially enter the whole country, Yicai said.

According to the report, the authorized Evusheld dosage in Hainan was 150 milligrams of tixagevimab and 150 milligrams of cilgavimab, administered as two separate consecutive intramuscular injections.

However, a source close to the issue told Yicai that, considering the potential for an epidemic caused by the BA.4 and 5 subvariants in China, the dosage would possibly be doubled. The adjustment would be made in the near future if necessary, according to the source.

As the BA.4 and BA.5 sub-variants seem to be able to substantially escape antibody response, it is necessary to increase the dosage of neutralizing antibodies to maintain its efficacy, Yicai said citing experts.

The increase in dosage would prolong the half-life period of the drugs in order to provide a longer period of protection and reduce the risk of secondary infections, Lu Hongzhou, head of the Third People's Hospital of Shenzhen, told the Global Times on Sunday.

The BA.5 sub-variant was reported on the Chinese mainland for the first time in May. Last week, infections caused by the BA.5.2 strain were first discovered in Xi’an, capital of Northwest China’s Shaanxi Province.

Following Xi’an, infections caused by the BA.5.2 strain have also been found in Beijing, Tianjin and Shanghai. A Shanghai health official said at a press conference on Sunday that gene sequencing showed that an infection discovered on Friday was caused by BA.5.2and related to a previous imported case.