Epidemiologist: Transmission of Covid-19 in Indonesia is 100 Percent from Delta Variant

Image Credit: Jakarta Post

The transmission of new cases of Covid-19 that is still occurring in Indonesia has entirely come from the Delta variant of SARS-CoV-2. Having a basic reproduction number of 5-8, this variant of the virus makes the vaccines used today have to be expanded to cover more than 100 percent of the population. This means herd immunity will never be achieved.

An epidemiologist from Airlangga University in Surabaya, Windhu Purnomo, revealed this calculation when contacted on Friday, November 19, 2021. “Now we have caught the Delta virus. From the whole genome sequence data, since the beginning of October or the end of last September, the existing samples are one hundred percent Delta,” he said.

The basic reproduction number of a virus is a term in epidemiology used to describe the infectiousness of a virus. The number 5-8 means that the Delta variant of the Covid-19 virus is able to spread from one infected person to 5-8 other people.

Compare this with the infectiousness of the Covid-19 virus when it first spread in Wuhan, China, which was only 2.4-2.6. Another comparison can be made to when the virus created the first Covid-19 wave in Europe last year, which had a contagiousness of 3, as well as the Alpha variant that spreads from the UK, which is 4-5.

In his calculations, Windhu uses an average vaccine efficacy value of 75 percent to represent a number of Covid-19 vaccines used in Indonesia, such as Sinovac, AstraZeneca, Pfizer, and Moderna. For the record, the largest number of doses used was Sinovac and then AstraZeneca.

As a result, the proportion of the population that must be vaccinated to achieve herd immunity is 111 percent, aka exceeding the population of Indonesia. “Especially if we include a more contagious Delta subvariant, like AY.4.2.? By now, we are already overwhelmed and herd immunity has not been achieved,” said Windhu.

That is why, Windhu assessed, the government is right to guard all entrances to this country from the possibility of the entry of new variants of Covid-19. Likewise with the quarantine and screening rules that are carried out. He hopes that no more mafia can ignore all the rules that have been made.

In addition, he emphasized the fixed principle that everyone should be vaccinated. The government must be able to achieve the target of one hundred percent, including educating those who have been resisting and avoiding. “At least try to 100 percent of the protective dose (full dose for each type of vaccine used), especially the elderly,” said Windhu.

He added that the government must also prepare a booster dose for the elderly and those with comorbidities that allow them to get the Covid-19 vaccine. “It should be free with a risk-based gift,” said Windhu.

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