2 Sinovac plus Pfizer booster less effective against Omicron variant
While Sinovac said they are still awaiting enough data to show the level of efficacy, a study at Yale University in the US shows that 2 doses of the Chinese-made vaccine with a booster shot of Pfizer look to be less effective against the Omicron variant of Covid-19 than the previous variants. The study was a collaboration between several institutions as well as the Ministry of Health of the Dominican Republic.
Full vaccinations of 2 doses of many different brands of vaccine have shown to be far less effective against the Omicron variant but the third booster shot for several vaccines including AstraZeneca, Moderna, and Pfizer have been tested to be effective against the variant. But this new study shows that a mixture of 2 Sinovac vaccines and one Pfizer shot yields results in protection similar to having only 2 doses of an mRNA vaccine.
Compared to the Delta variant, the antibody level of protection against Omicron was 2.7 times lower with this 3 vaccine mix, and 6.3 times less effective against the original strains. The study sampled 101 people in the Dominican Republic and showed that just 2 doses of Sinovac did not offer any significant protection against the Omicron variant.
It was suggested that those who were originally vaccinated with 2 doses of Sinovac may be best off getting not just one booster but a second booster to offer full protection against the new variant, according to a tweet by one of the researchers involved in the study.
In Hong Kong, another study last week found that those who had received even 3 doses of Sinovac may still not produce enough Omicron-fighting antibodies to be effective and that a booster shot of Pfizer should be administered. Hong Kong has been using Sinovac and Pfizer for the majority of its vaccinations.
Sinovac is also the most used vaccine globally because of the mass production and distribution throughout China, Southeast Asia, and worldwide, so another round of boosters might be in order for millions of people around the world.
SOURCE: Asian News Today
