Sinovac vaccine. The Centre for Health Protection's Chuang Shuk-kwan said that the Ming Pao report was inaccurate and has defended CorovaVac, saying "The issue is not about which jab offers more protection. The most important thing is whether you get vaccinated." Earlier in February 2022, health authorities refused to disclose data on which COVID-19 vaccine had been taken by Omicron patients, claiming the information "was not readily available." Hong Kong government data showed CoronaVac to be the preferred vaccine among those aged 70 and over, in part because some elderly care homes only offer this vaccine. However, CoronaVac's limited effectiveness compared to the BioNTech vaccine, along with the zero-COVID strategy, have been regarded as factors behind Hong Kong's spiking cases as of March 2022. Politicization CoronaVac has been championed by the governor of São Paulo, João Doria. A political showdown began in October 2020, when Bolsonaro vetoed a deal between the Brazilian health ministry and the São Paulo government for the purchase of 46 million doses of the vaccine. After Instituto Butantan announced CoronaVac's efficacy rate, Bolsonaro mocked the vaccine's effectiveness against COVID-19. In March 2021, the Paraná Pesquisas opinion polling institute found that the vaccines preferred by Brazilians are CoronaVac and the Oxford–AstraZeneca vaccine, chosen by 23.6% and 21.2% of Brazilians interviewed, respectively, against 11.3% of those who would prefer the Pfizer–BioNTech vaccine. During the pandemic parliamentary inquiry in Brazil, senators have expressed that anti-China rhetoric has contributed to delaying access to vaccines in Brazil. Delays in releasing results On 23 December 2020, researchers in Brazil said the vaccine was more than 50% effective, but withheld full results at Sinovac's request, raising questions about transparency as it was the third delay in releasing results from the trials. Scientists said the lack of transparency risked damaging CoronaVac's credibility. References Further reading External links Clinical Research Protocol for CoronaVac Phase III Trials in Brazil Clinical trials Chinese COVID-19 vaccines Inactivated vaccines Products introduced in 2020