| Abstract |
: |
Vaccine-induced population immunity is a key global strategy to control the COVID-19 pandemic, and to date eight COVID-19 vaccines have received Emergency Use Listing (EUL) by the WHO. Indonesia has been one of the global epicenters of the COVID-19, only behind India in the Asian region. By June 2022, the reported total number of Indonesian people infected with SARS-CoV-2 is 6,1 million people (approximately 3.5% of the Indonesian population), and the death toll has reached 157,000. In Indonesia, vaccination roll-out was initiated in January,2021, and as many as 167 (80%) and 44 (21%) million people have received their second and third dose, respectively. Most people received two primary doses of Coronavac (SinoVac, an inactivated SARS- CoV-2 virus) or, in lesser amounts, ChAdOx1-S (AstraZeneca, a viral vector vaccine), BNT162b2 (Pfizer- BioNtech) or m1273 (Moderna, both mRNA vaccines). In August 2021, the Indonesian government implemented a heterologous booster vaccine strategy for health care workers that received the third (booster) dose vaccine with an mRNA vaccine (Moderna); in January, 2022, the general population was offered a booster of a half dose of Moderna or Pfizer vaccine (after two doses of AstraZeneca), or a half dose of Pfizer or AstraZeneca (after two doses of Coronavac). A lot of uncertainty remains around which vaccines are the most effective, how many doses are needed to induce long-term immunogenicity, what is the role of natural infection, and whether homogenous or heterogenous vaccine combinations confer better protection, and further investigations are needed in real-world vaccine effectiveness (VE) studies. One of the specific challenges with the rapid emergence of novel SARS-CoV-2 variants is whether the available vaccines and booster regimens confer optimal protection against the new variants. There has been limited scientific evaluation of the effectiveness of the Government of Indonesia vaccine programme, including the various booster combinations, especially in the face of Omicron. Therefore, this study aims to investigate the effectiveness of COVID-19 vaccinations against symptomatic COVID-19 among the general population in Indonesia. |
