Evaluating the experience of countries such as Indonesia, Sinovac's CoronaVac poses considerable risk of "vaccine breakthrough," says Singapore Ministry of Health's Director of Medical Services, Kenneth Mak.
Made-in-China vaccines have again raised concern after more than 350 healthcare professionals contracted novel coronavirus in Indonesia despite being vaccinated with the World Health Organization (WHO) approved Sinovac jab, officials said.
Badai Ismoyo, head of the health office in the district of Kudus in Central Java, said that most of these infected people were asymptomatic and self-isolating at home. But dozens of people have been admitted to hospitals with high fevers and low oxygen saturation levels. It was also reported that Kudus, which has around 5,000 people working in healthcare, is dealing with an outbreak caused by the more transmissible Delta variant, which has pushed bed occupancy rates beyond 90 per cent.
Healthcare workers, who were designated as a priority category, were among the first to be vaccinated when vaccinations began in January this year. According to the Indonesian Medical Association, almost everyone has received the Covid-19 vaccination made by the Chinese biopharmaceutical company Sinovac.
Between January and May, the number of healthcare workers in Indonesia dying from Covid-19 declined from 158 to 13. But the public health experts said that the unprecedented hospitalisation numbers in Java are concerning.
As per the WHO, a large Phase III trial in Brazil found that two doses, given 14 days apart, had a 51 per cent efficacy against symptomatic coronavirus infection, a 100 per cent efficacy against severe Covid-19 and a 100 per cent efficacy against hospitalisation commencing 14 days following the second dose.
It was also said that in an observational study, “the estimated effectiveness of Sinovac vaccine CoronaVac in health workers in Manaus, Brazil, where P.1 (Gamma variant) accounted for 75 per cent of SARS-CoV-2 samples was 49.6 per cent against symptomatic infection. Effectiveness has also been shown in an observational study in Sao Paulo in the presence of P.1 circulation (83 per cent of samples)”.
According to the WHO website, assessments in settings where the P.2 or Zeta variant was widely circulating in Brazil estimated vaccine effectiveness of 49.6 per cent following at least one dose of the vaccine and demonstrated 50.7 per cent two weeks after the second dose.
But Dicky Budiman, an epidemiologist at Australia's Griffith University told CNN: "The data shows they have the Delta variant (in Kudus) so it is no surprise that the breakthrough infection is higher than before, because, as we know, the majority of healthcare workers in Indonesia got Sinovac, and we still don't know yet how effective it is in the real world against the Delta variant”.
Amid one of Asia's worst outbreaks, with over 1.9 million infections and 53,000 deaths, Indonesia's doctors and nurses have suffered a heavy toll of 946 fatalities. Despite being vaccinated, at least five doctors and one nurse have died from Covid-19 in Indonesia. Dr Prijo Sidipratomo, a radiologist in Jakarta said that he knew of at least half a dozen doctors who had been hospitalised with Covid-19 despite having vaccinated in the previous month, with one still being treated in an ICU. He said: "It is alarming for us because we cannot rely on vaccinations only".
Apart from Indonesia, some other countries also witnessed a spike in cases even after launching a vaccination drive using Chinese jabs developed by Sinovac and Sinopharm. On 18 June, the Singapore Ministry of Health's (MOH) director of medical services, Kenneth Mak, said that the Sinovac’s CoronaVac poses a considerable risk of "vaccine breakthrough," with international evidence indicating that many people who received it later became sick with Covid-19.
While speaking to reporters at a virtual media briefing—while responding to questions on whether Singapore will introduce Sinovac jabs into the national vaccination program—Mak said that the authority has been evaluating the experience of countries such as Indonesia, which has used CoronaVac to vaccinate a "larger proportion" of the population.
According to him, "It's not a problem associated with Pfizer. This is actually a problem associated with the Sinovac vaccine, and in other countries, they are now starting to think about booster vaccinations, even six months out from an original vaccination for some of these vaccines as well”.
It gives the idea that the performance of different vaccinations will vary very dramatically, Mak said while adding that Singapore has "great confidence" in the Pfizer-BioNTech, as well as Moderna vaccines, of which over 4.7 million doses have been administered in the South-East Asian country.
Singapore MOH has granted licences to 24 healthcare institutions to distribute the Sinovac vaccine to anyone who chooses to get it. These institutions were chosen as licenced providers under the Special Access Route (SAR) under the Private Hospitals and Medical Clinics Act (PHMCA). However, Sinovac remains unregistered by the Health Sciences Authority (HSA) and will only be available through the SAR framework. It means that it will not be covered by the Vaccine Injury Financial Assistance Program (VIFAP), which is intended for the national vaccination programme.