PUTRAJAYA: The Delta variant of the Covid-19 virus is at least two times more transmissible, being able to infect the next person within 15 seconds.
Health director-general Tan Sri Dr Noor Hisham Abdullah said the normal Covid-19 virus has an infectivity rate or R-naught (Rt) of between 2.5 and 3.
The Delta variant, in comparison, has a higher Rt of between 5 and 8.
"This means that for every 100 people infected, it could spread to 500 to 800 others.
"In the past, positive cases happen if someone comes in close contact with an infected person for 15 minutes or less than one-metre apart.
"Now with the Delta variant, infections can happen within 15 seconds, and the infection is now airborne," he said in a joint press conference on Covid-19 and the Greater Klang Valley with Health Minister Datuk Seri Dr Adham Baba.
Dr Noor Hisham added that the high transmissibility of the Delta variant required everyone to increase public health practises, including putting on face masks, physical distancing, and avoiding crowded and confined places.
"Vaccination is also one way to curb the spread within the community, as seen clearly in Labuan, where the Delta variant was detected through genomic surveillance."
He said the infectivity rate in Labuan was very high, with the highest number at 1,340 cases per week.
The majority of the cases there, he added, originated from workers in the shipping industry.
"For two weeks, we conducted public health measures and ramped up vaccinations.
"To date, 52 per cent of the people in Labuan have received their second dose, and 87 per cent have been vaccinated with their first dose. With this, we have managed to control and lower the number of cases in less than three weeks," said Dr Noor Hisham.
He said an additional five million doses of vaccines would be administered in the Klang Valley soon to ensure that all in the area were vaccinated with at least their first dose by Aug 1.
With the increase in people being vaccinated, the number of patients being admitted into hospitals for Covid-19 would decrease, he added.
Meanwhile, Dr Noor Hisham also said the ministry forecasted that cases would see a decline by the end of November if the country administers at least 100,000 second vaccination doses per day, provided the Rt remained at 1.2.
Cases would see a decline by October if at least 150,000 second vaccination doses were administered per day, he said.