The Sinovac Vaccine Shows a Decrease in Efficacy, and It Turns Out AstraZeneca and Pfizer Are the Same

The Indonesian people are shocked by research results showing that the Sinovac vaccine's efficacy decreases 3-6 months after the vaccine. As it turned out, not only the Sinovac vaccine but the AstraZeneca and Pfizer vaccines also showed a decrease in efficacy after several months.

Have you had the COVID-19 vaccine? If you are considering which vaccine to choose, read the following article to learn the types, methods, and efficacy of the COVID-19 vaccine circulating in Indonesia.

1. Sinovac vaccine

The Sinovac vaccine is the most widely used in Indonesia, Africa, Latin America, and Southeast Asia. The vaccine produced in China is a whole virus type vaccine that utilizes the inactivation of the SARS-CoV-2 virus. This inactivated virus can trigger the formation of immunity in the body without infecting it.

Studies in Indonesia show that the efficacy of the Sinovac vaccine is 65.3%. However, efficacy decreased to 50% after 3-6 months post-vaccine. Meanwhile, a study from the University of Hong Kong laboratory proved that the two-dose Sinovac vaccine failed to produce detectable antibodies against Omicron. The World Health Organization also recommends that Sinovac users get a booster vaccine immediately.

2. AstraZeneca vaccine

The AstraZeneca vaccine is produced by a biopharmaceutical from England in collaboration with the University of Oxford. Several countries that have used this vaccine include Vietnam, India, Malaysia, the Philippines, Taiwan, and Korea.

This vaccine is a viral vector type by utilizing an attenuated chimpanzee adenovirus. This vaccine was developed by taking a virus that usually infects chimpanzees and genetically modifying it to carry the spike protein from Covid-19. When it reaches human body cells, this vaccine will trigger an immune response and produce antibodies and memory cells that can recognize the virus that causes Covid-19.

The efficacy of the AstraZeneca vaccine was at 68%. It decreased to 61% in the second week after the second dose of the vaccine. This decline in efficacy was more pronounced in those aged 35 years and over.

3. Pfizer vaccine

The Pfizer vaccine is a vaccine from Germany that was first used in the United States. This type of vaccine was developed based on messenger RNA (mRNA) technology. Because it uses a synthetic gene, this vaccine is easier to create. It can be produced more quickly than conventional technology.

Unlike the two traditional vaccines mentioned earlier, vaccines come from weakened or inactivated viruses that trigger an immune response. Vaccines with mRNA technology work to teach cells to produce a protein, or a piece of protein, that triggers an immune response in the body.

The Pfizer vaccine has an efficacy rate of 95%. With a high level of efficacy, World Health Organization recommends using the Pfizer vaccine in a country, even if a new variant is endemic in that country. However, according to data from the Israeli Ministry of Health, this vaccine also showed a decrease in efficacy from 94% to 64%.

Those are the characteristics of the three vaccines most widely circulated in Indonesia. It can be concluded that each vaccine has a different level of efficacy which will decrease over time.

It should be remembered that even though the efficacy level of the vaccine has decreased. Everyone needs to get the vaccine to prevent the severe consequences of Coronavirus infection. You can also get a third or booster dose of the vaccine, which will be implemented in Indonesia to increase the body's immune response against the new Omicron variant.